Re: Topband: KD9SV-OK1RR relays ??? (RX Front End Protector)
Perhaps common-mode isolation of currents induced in the antenna coax shield?? Charlie, K4OTV Lee K7TJR k7...@msn.com wrote: Hmmm, I wonder why the Array Solutions circuit board picture shows MCL 1:1 transformers. Sounds fishy to me. Even the waveform pictures show clipping at a 1:1 with one diode voltage. Hmmm? Lee K7TJR _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Which is best for copying the weakest DX - DSP or the ear-brain combo?
Some years ago, a few of us would occasionally have QSOs that we called Martin Luthers -as in I had a DREAM last night! and we'd send off the QSLs and would often get one back! This was especially true on 160. I still, occasionally , have a Martin Luther! Straining right down into the noise level and QSB for ESP-level signals! 73 Charlie, K4OTV Greg Zenger n...@gregzenger.com wrote: I suspect a well trained and practiced brain may be able to out perform a DSP assisted average brain... However over the course of a contest (24-48 hours of [near] continuous operating) a DSP assisted average brain may have an advantage due reduced listening fatigue... Of course some DSP can positively contribute to listening fatigue and others negatively... Quality of DSP and operators ability to adjust are key factors here. This is a topic I follow closely, but can't think of any articles or studies off hand that would answer your question... A sold PhD thesis topic this would be. Greg N2GZ On Aug 4, 2015 9:02 PM, Roger D Johnson n...@roadrunner.com wrote: Although I don't consider myself among the highly-skilled and talented, I can't think of an instance where DSP made the difference between making a contact or not. I do have an Autek QF-1A wired into the audio of the main receiver of the K3 as the AudioPeakingFilter on the K3 is too sharp. 73, Roger N1RJ On 8/4/2015 8:25 PM, Art Snapper wrote: Mike, Are you referring to a specific modulation mode? How about adjacent channel interference issues? I like your question. Art ᐧ On Tue, Aug 4, 2015 at 7:39 PM, Mike Watersmikew...@gmail.com wrote: I'd like to know whether it's ever been established that some very talented hams can out-hear the best SDRs and/or DSP available. Can a skilled ear-brain combo (such as some highly-skilled and talented 160 meter contesters) beat state-of-the art digital signal processing when it comes to copying the very weakest of signals buried in the noise? I always thought Linrad was the best DSP software, though I never got it working right here (older sound card issues in Xubuntu). I asked the following question at http://www.eham.net/ehamforum/smf/index.php?topic=104388.msg861047#msg861047 : Are there any people who can hear weak signals with a good analog receiver, who --if they could instantly switch their antenna and headphones from the analog RX over to the best SDR made today-- simply couldn't hear any better with today's best SDRs and/or DSP software? There's been a few opinions, but how about multiple valid tests? 73, Mike www.w0btu.com _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: 160 Tower on 80
Hi, Glenn There's a lot to be said for Rich's approach if you can manage the additional tower. It does need to be well separated from the 160 tower as some interaction is likely. You might want to do some modeling in EZNEC before installing the additional tower. Still phased, or parasite arrays can provide substantial results for 80 and 160! I built a large 5- element steerable array for a friend for 80 meters. It had a central 1/4 wave GP radiartor and 4 surrounding GPs that could be switched between reflector and director tuning with stubs of ladder line that could be remotely shorted with relays to achieve different directions. It was a KILLER antenna for 80 and 75 meters and Jim didn't wait fr anything!! - Even to breaking EU pile-ups for A61 with ONE CALL from Virginia!! It was a HUGE success! So, some variatiom of Rich's approach might well have merit! I would strongly recommend some advance modeling and experimentation with EZNEC before installing the second tower. I have thought of putting an 80m trap in the top horizontal wire for my inverted L, but I didn't like the idea of an 80 m trap 70' in the air. So I elected to add a 2nd vertical radiator for 80m and feed it in parallel with the 160 inverted L. That's also an option for you, if you add an 80m radiator in parallel and run it up the side of your tower. If you are using elevated radials, you[ would need to add an additional set for 80m. Anyway, GL and have fun! 73, Charlie, K4OTV -Original Message- From: KL7RA [mailto:kl...@ptialaska.net] Sent: Saturday, February 28, 2015 10:53 PM To: Charlie Cunningham; 'Glenn Biggerstaff'; topband@contesting.com Subject: Re: Topband: 160 Tower on 80 Any thoughts or alternative ideas would be greatly appreciated. Glenn WW4B Hi Glenn, all of Charlie's, K4OTV ideas work of course but you did mention alternate ideas. I also have a Rohn 25 insulated base tower that is 142 feet to the top of the stinger that I use for 160. By far and the easiest solution 100% guaranteed to work for a clean switch from 80 to 160 is a second tower some distance away. Used 25 is relatively cheap and Philly now is sold by a lot of folks. The only switching is in the shack, etc. Simple is good. I chose not to use the 2nd tower as a vertical and it supports a 4 square using the DXE hybrid. For the radiating elements I used dipoles with shield end sharply folded back to the tower. Because the elements come pretty close together at the top you do lose a little gain but not that much over verticals and verticals require a lot of radials where this array just has the one element folded back for each direction. This array seems to work so well I build another for 40 meters under a full size 40 Yagi. At times the Yagi is better as expected but the ops here like the instant switching and use it a lot. Added bonus these arrays survive the winter storms here with 100 mph + winds. 73 Rich KL7RA (now on topband but no one can hear me yet.) Well, Glenn, I would lean toward voltage-feed at the base, since you have that insulated tower! Because of the lower current, the ground-losses would be minimized, and the current maximum would be fairly high on the tower, resulting in a nice low-elevation angle, omni-directional radiator for long haul 80m DX work. Of course you would need a robust tapped parallel LC network with a robust inductor, probably mad of copper tubing and a really high voltage air variable capacitor, or better, a vacuum variable and there would be some substantial switching challenges to switch the feed between 80 and 160, that would be avoided with your trapped top loading approach, but full-power 80m traps 90' in the air are non-trivial components also! I LIKE the voltage-fed 1/2 wave vertical approach and have had wonderful success with it on 40m, where I fed the vertical 1/2 wave through a 1/4 wave 450 om line for an almost perfect match!! Great antenna. And I used it as the driver for a wide-spaced 3-element vertical 40m yagi for Peter 1 Island and Bouvet and it was a killer antenna for SE Asia on the evening LP. So, that's my $0.02! If it were me, I'd leave the top-loading alone and do the work to voltage feed that insulated tower! Should be a great antenna for both 80 and 160, and has the advantage that all the tinkering and tweaking can be done at ground level! GL and have fun!! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Glenn Biggerstaff Sent: Saturday, February 28, 2015 8:16 PM To: topband@contesting.com Subject: Topband: 160 Tower on 80 Hi all, I have a 90 foot Rohn 25 tower with an insulated base and insulated guy wire sections for top loading ,base fed for 160 meters. It work great ,but I would like to use it on 80 meters as well. The 3 ideas I have considered are voltage feed at the base with a resonant LC network at the base
Re: Topband: 160 Tower on 80
Well, Glenn, I would lean toward voltage-feed at the base, since you have that insulated tower! Because of the lower current, the ground-losses would be minimized, and the current maximum would be fairly high on the tower, resulting in a nice low-elevation angle, omni-directional radiator for long haul 80m DX work. Of course you would need a robust tapped parallel LC network with a robust inductor, probably mad of copper tubing and a really high voltage air variable capacitor, or better, a vacuum variable and there would be some substantial switching challenges to switch the feed between 80 and 160, that would be avoided with your trapped top loading approach, but full-power 80m traps 90' in the air are non-trivial components also! I LIKE the voltage-fed 1/2 wave vertical approach and have had wonderful success with it on 40m, where I fed the vertical 1/2 wave through a 1/4 wave 450 om line for an almost perfect match!! Great antenna. And I used it as the driver for a wide-spaced 3-element vertical 40m yagi for Peter 1 Island and Bouvet and it was a killer antenna for SE Asia on the evening LP. So, that's my $0.02! If it were me, I'd leave the top-loading alone and do the work to voltage feed that insulated tower! Should be a great antenna for both 80 and 160, and has the advantage that all the tinkering and tweaking can be done at ground level! GL and have fun!! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Glenn Biggerstaff Sent: Saturday, February 28, 2015 8:16 PM To: topband@contesting.com Subject: Topband: 160 Tower on 80 Hi all, I have a 90 foot Rohn 25 tower with an insulated base and insulated guy wire sections for top loading ,base fed for 160 meters. It work great ,but I would like to use it on 80 meters as well. The 3 ideas I have considered are voltage feed at the base with a resonant LC network at the base, but I am a little worried about the voltages present at legal limit power. Second idea,disconnect the top loading and put a trap between the top loading and the tower to divorce the top loading on eighty then an L network at the base for 80. Third idea, run a wire as a sloper either a quarter wave fed against ground or a 1/2 wave dipole from the tower. Any thoughts or alternative ideas would be greatly appreciated. Glenn WW4B _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: 160M CQ WW SSB this weekend - Frequencies
Í would leave it alone, Mike! Your tuner or amplifier should be able to tune out that small bit of reactance, I would think! And on 160 the excess loss in the coax from a bit of VSWR is really negligible! GL! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Mike Waters Sent: Friday, February 27, 2015 2:03 PM To: topband Subject: Topband: 160M CQ WW SSB this weekend - Frequencies Can anyone suggest the best freqs. to tune our 160m inverted-L for the CQ WW SSB contest this weekend? The antenna is a long way from the house, andt's tough to do that in the pitch dark and cold. :-) It seems to me that in the past, it's been about where the CW contests always take place, and mine is now tuned for 1810 to 1850 or so. Is that OK as it is now, or should I move it up? www.cq160.com/rules.htm Thanks. 73, Mike www.w0btu.com _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: K1N 5,399 q's on 160 M
The joys of Internet DXing!! Everybody that comes on is swamped by packet-rats!! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Kenneth Grimm Sent: Thursday, February 19, 2015 10:37 AM To: GALE STEWARD Cc: topband@contesting.com Subject: Re: Topband: K1N 5,399 q's on 160 M And how about the clown last night, around 10pm his local time, when TI9/3Z9DX was working EU, who got on his frequency and said, NA NA NA, I'm tired and need my sleep. I didn't know whether to laugh or cry. 73, Ken - K4XL On Thu, Feb 19, 2015 at 8:18 AM, GALE STEWARD via Topband topband@contesting.com wrote: Exactly the point, Steve! A bunch of the guys around here worked them on 160 at 0800Z (that's 3AM here). My 160 QSO was around 1030Z. I'm really dating myself but back in the day the only way to snag some new ones on 80/160 was to be checking the bands in the middle of the night. No internet cluster, etc. It's actually a lot easier these days (my opinion). When my daughter was an infant this was easier as I was usually up in the middle of the night at least once! 73, Stew K3ND From: Steve Flood kk...@bresnan.net To: topband@contesting.com Sent: Thursday, February 19, 2015 6:25 AM Subject: Re: Topband: K1N 5,399 q's on 160 M Great points Chet. Under the Be there category, consider getting up in the middle of the night to work them on the low bands. Even in the first days of their operation, I got up at 2 a.m. and worked them easily on 160-80-40 with 100 watts and no pileups. Steve KK7UV --- This email has been checked for viruses by Avast antivirus software. http://www.avast.com _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband -- Ken - K4XL BoatAnchor Manual Archive BAMA - http://bama.edebris.com Show me a politician who is poor, and I'll show you a poor politician. - Carlos Hank González _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: K1N 5,399 q's on 160 M
True, George1 Those were excellent times for 160, 80 and 40m and worked well for me! There's a lot to be said for keeping an eye on the daylight map and being where the competition isn''t! My 160 antenna has been down for a few years, but I had a very easy 160 QSO with K1N using the remnant of my 80m GP with only one radial! Great job! Thanks! 73. Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of GeorgeWallner Sent: Tuesday, February 17, 2015 9:28 PM To: jon jones; topband@contesting.com Subject: Re: Topband: K1N 5,399 q's on 160 M Jon, I was one of the 160 m operators. NA callers were thick during the evening hours when they were competing with EU, making for some difficult pile-ups, but after midnight (and EU sunrise), often there were very few NA callers. George AA7JV On Tue, 17 Feb 2015 22:57:38 + jon jones n...@hotmail.com wrote: I consider VP6DX to be one of the top all time 160 meter DX operations. Despite being thousands of miles from North America, they worked many small stations including me (at the time had just moved so a random wire thrown over the house and 100 watts). K1N had a great signal on 160, well over S-9 most nights - but seemed to be having difficulty hearing callers. Despite a full size inverted L, I was not QSO 5,400... - Jon N0JK IMHO the operations at 5A7A, K5D, K1N, R1MVW, HK0NA, TS7C,and TX5K did an extremely good job and were able to take advantage of the proximity to major population areas. They had to have a good station and great operators, and had to be on the ground long enough to take make the large amount of Qs. But, and again IMHO, the operations at VP6DX, T32C, and ZL8X are OUTSTANDING because they had to overcome the big one; DISTANCE, for nearly 100% of their Qs. Now to separate those three just a bit. ZL8X did 4,206 Qs with a crew of 14 operators and 18 days of operation. T32C did 4,985 Qs with a crew of 41 operators and 32 days of operation. VP6DX did 6,671 Qs with a crew of 13 operators and 17 days of operation. 73 de Milt, N5IA _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: K1N 5,399 q's on 160 M
Jon, If you haven't already, check this app out! It was just great figuring out time slots to try the various bands for the K1N expedition! It's a VERY useful tool for DXers - especially low-band DXers! Sure beats the old plastic DX Edge that we used in the old days. Very useful for looking at the gray-line (terminator ) as it changes daily throughout the year and watching in real time as the sun and daylight and darkness move over a Mercator projection of a map of the earth. Try it! You'll like it!! Enjoy! 73, Charlie, K4OTV http://www.world-timezone.com/daylight-map/ -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of jon jones Sent: Tuesday, February 17, 2015 10:45 PM To: topband@contesting.com Subject: Re: Topband: K1N 5,399 q's on 160 M George: Thanks for the note. All the K1N ops did an outstanding job ! That is an excellent tip re. getting on after European sunrise and before JA sunset for DXpeditions on the low bands. I got up a number of nights ~ 2 am - 4 am CST to try for K1N. I was successful on 40 and 80 meters with K1N during this time slot. - Jon Jon, I was one of the 160 m operators. NA callers were thick during the evening hours when they were competing with EU, making for some difficult pile-ups, but after midnight (and EU sunrise), often there were very few NA callers. George AA7JV _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: HC1PF on TB Tuesday 17th February 2015
Well, do keep in mind, Rune, that it's summertime in Ecuador, and he has summertime QRN, whereas it's wintertime in LA , so the band is quieter where you are! J 73, Charlie,K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Rune Øye Sent: Tuesday, February 17, 2015 2:29 AM To: topband@contesting.com Subject: Topband: HC1PF on TB Tuesday 17th February 2015 HC1PF was literally 5NN around 10 min before my local SR this morning. Most of the time he is 559 to 579. Seems there is many EU stations on but many suffer the same as me :-) still not in log. I guess he has an RX issue noisy band none RX antenna etc. However we cant complain about his effort. 73 Rune LA7THA _ Topband Reflector Archives - http://www.contesting.com/_topband http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: K1N DQRM Tracking Project
Actually ,Jim, the velocity of propagation of radio waves (or light waves) in free space is about 1 foot/nanosecond, NOT 1 foot per microsecond. It would seem to me that one needs to have a measure of directivity as well a s time, an the time factor might boil down to phase difference measurements. Thinking of applying all of this to something complex like SSB modulation sounds pretty messy. And a lot of the interference originates outside our borders, so I don't see who would be the enforcement body? Just my $0.02 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Jim Garland Sent: Sunday, February 08, 2015 9:08 PM To: 'Lee K7TJR'; Topband@contesting.com Subject: Re: Topband: K1N DQRM Tracking Project I agree, Lee. Locating a DQRM station involves accurately time stamping the arrival time of their transmissions, at (at least) three receivers at known locations. Once the arrival times are known, one can use trigonometry to calculate the location of the interfering station. Since radio waves travel about one foot in a microsecond, and since a microsecond is an eternity by modern frequency counter standards, it should be possible to get very precise locations. The city block mentioned earlier should be readily doable. Of course, this requires that the three receivers be able to copy the DQRM ground wave signal, since the arrival times would otherwise be dependent on ionispheric reflections. More than three receivers would result in more accurate position measurements.. There's no need to use direction finding equipment, which are very low resolution by comparison with time measurements.. I'm no authority on FCC rules, but I'm under the impression that deliberately interfering with other licensed transmissions is against the law. Every month or so, the FCC nails some renegade ham or CBer for doing just that. Probably just publicizing the callsign of the culprits would be a large deterrant for all but the most sociopathic offenders. 73, 'Jim -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Lee K7TJR Sent: Sunday, February 08, 2015 4:47 PM To: topband@contesting.com Subject: Re: Topband: K1N DQRM Tracking Project Greetings top-band community, Interestingly enough the technology exists right here in our own Ham community that could go a long way toward finding these DQRM culprits. There are some beam forming arrays that operate with SDR technology where a recording can be made of a target bandwidth and later reviewed with beam forming techniques to DF using a peak or notch completely after the event has long gone. In fact directional and strength data can be stored in perpetuity. So my comment is don't underestimate the ability to identify these idiots. Being able to actually replay an entire contest and do a strength and directional analysis in a narrow bandwidth after the fact to me is the ultimate receiving system. Lee K7TJR OR I'd be interested in some project like that, but I'm afraid it would only get to a general area. With maybe 3-10 idiots at any one time, and the 3-10 active at any time probably varying every hour, it might be pretty tough to do anything meaningful. Since attention is what they want, I wonder if this effort would not encourage participation in jamming at a faster rate than it solves anything? Has anyone ever looked to see if there is any correlation between intentional QRM and the DX station spreading people over a wide swath of the band? More than once, I've heard people intentionally threaten to QRM DX because they were POed that their QSO was interrupted by a pileup. 73 Tom _ _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: K1N DQRM Tracking Project
Amen! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Doug Renwick Sent: Sunday, February 08, 2015 2:34 PM To: topband@contesting.com Subject: Re: Topband: K1N DQRM Tracking Project A poster on the cluster said it the best: DQRM triangulation = nonsense idea! There is no way this is going to identify the offending station(s). IMO at best a bluff. Doug -Original Message- Is anyone using this DQRM Tracking Project report? They want reports of deliberate QRM like 'tuner uppers' and other types, but not QRMers like cops or 'no splitters'. I don't know how accurate they can be to identify the guilty station on any band especially 160m with or without a directional antenna. --- This email has been checked for viruses by Avast antivirus software. http://www.avast.com _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: K1N DQRM Tracking Project
I surely don't think so! I don't expect that there is any way, unless ALL amateur transmitters were equipped with an embedded address encoder and supplied the owner/operator's call and the station GPS coordinates!! My $0.02 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Peter Voelpel Sent: Sunday, February 08, 2015 9:12 PM To: topband@contesting.com Subject: Re: Topband: K1N DQRM Tracking Project Are you sure that will work with sky wave signals? 73 Peter -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Lee K7TJR Being able to actually replay an entire contest and do a strength and directional analysis in a narrow bandwidth after the fact to me is the ultimate receiving system. _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: K1N On Line Log
And another more important point, Kevin in the case of such a massive need as K1N. Several of the operators were complaining about the number of dupes in the logs. That's caused by guys not knowing if they had a good QSO and just continuing to call. I Tune around in the CW pileups a LOT to find where the stations are calling that the DX is working and to find a slot where I can insert my call. I have personally heard a number of guys that were worked by K1N and went right on calling in the pile because they simply didn't know they had worked them!! What's wrong with that picture?? In those cases the operators just weren’t adept enough to enact the simple procedures that I outlined, and they just continued to add to the pandemonium in the pile-up and making things more difficult for everyone! That just adds to the QRM and slows everyone down!! 73.l Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of kol...@rcn.com Sent: Saturday, February 07, 2015 1:36 AM To: topband@contesting.com Subject: Re: Topband: K1N On Line Log Charlie, I don't think many here didn't know if they made a contact or not. The question was if K1N had lost their QSO from the computer log. No matter how sure you are you made the contact, if it's not in their computer log, for whatever reason, it can't be confirmed. Kevin K3OX - Original Message - From: Charlie Cunningham charlie-cunning...@nc.rr.com To: Eddy Swynar deswy...@xplornet.ca, topband@contesting.com Sent: Saturday, February 7, 2015 12:46:02 AM Subject: Re: Topband: K1N On Line Log Well, we did survive just fine, Eddy and lots of folks mad the Honor Roll, 5BDXCC etc.. All this nonsense about the online logs is just so much Bull!!! Can all be avoided if folks would do the following:\ 1.0COPY your own call!!! No guesswork, no fragments, no bluffing etc. 2.0 Copy your report 3.0Reply with your call, followed by an acknowledgement of DX Station Report (TU or thanks) and Send report to DX station followed (or preceded) by Thanks or TU 4.0LISTEN for the DX operator to acknowledge your report 5.0 Thanks or TU -or even dit-dit Do those things completely and there won't be much guessing or wondering if you had a legitimate QSO that's logged!! We may have to have some patience and perseverance to work through the jammers, and QRM and the packet-rats tuning up on the DX QRG! It may be reassuring to see the online logs, but we should KNOW if we had a good contact or not! WITHOUT a computer to tell us we did!! I KNEW that my 7 QSOs with K1N were there BEFORE the logs came out! And NO DUPES or INSURANCE CONTACTS!Just my $0.02. 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Eddy Swynar Sent: Friday, February 06, 2015 3:17 PM To: topband@contesting.com Subject: Re: Topband: K1N On Line Log How did we EVER collectively survive the dark ages of hardcopy QSL cards, s.a.s.e.'s, QSL bureaus, DX news sheets, and I.R.C.s, I wonder...? Is everyone that impatient while attempting to WORK a rare station, too...? All this angst and trepidation being displayed here...! I thought DX'ing, Ham radio, Topband were all supposed to be FUN, and not a hand-wringing exercise in anger worry management... ~73~ de Eddy VE3CUI - VE3XZ _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Is self-spotting ALWAYS wrong?
I agree, Gary. Over the years I've seem a number of DX stations do that - especially on quiet bands or if they have more modest stations, or are in really far-away places. It's never bothered me and I've always just viewed as an invitation and an announcement that they are QRV. Of course, alerting the packlet-rats, is likely to get a lot of action! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Gary Smith Sent: Saturday, February 07, 2015 5:38 PM To: Topband@contesting.com Subject: Re: Topband: Is self-spotting ALWAYS wrong? I don't think it's wrong, it says you're QRV here's where to find me. Sounds good to me. 73, Gary KA1J --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: K1N DQRM Tracking Project
I haven't bothered with it, Doug. I see it mostly as an exercise in futility. The cops never ID, and the MOST TROUBLESOME QRM is from packet-rats seeing the spots and then tuning up interminably on to he DX QRG - of course they never ID either - and they are too lazy and inconsiderate to move off the DX QRG to tune up!! :( 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Doug Renwick Sent: Saturday, February 07, 2015 6:05 PM To: topband@contesting.com Subject: Topband: K1N DQRM Tracking Project Is anyone using this DQRM Tracking Project report? They want reports of deliberate QRM like 'tuner uppers' and other types, but not QRMers like cops or 'no splitters'. I don't know how accurate they can be to identify the guilty station on any band especially 160m with or without a directional antenna. See below: THE DQRM TRACKING PROJECT --- Recently, the amount and intensity of DQRM (Deliberate QRM) has been growing logarithmically, targeting DXpeditions all over the world. DQRMers attempt to spoil communications and disrupt the joy of chasing DX. Without going into the motivation of DQRMers, the DX Community is taking steps to eliminate this practice. The KP1-5 Project, which is producing the 2015 K1N Navassa DXpedition, has been working with tele-communications agencies around the world. The objective is to identify stations who are acting as DQRMers and use legal means to stop this behaviour. The technology is in hand to solve this problem and, with your assistance, we can stop this blight that is hurting hams worldwide. HOW IT WORKS: Locating the stations engaging in DQRM is a matter of triangulation. When the DQRMer is 60db over S9 at your location, you can be pretty sure that station is nearby. If you fill out the form at www.dqrmreport.com, the data will be collected and analyzed to produce a reasonably accurate map of the DQRMer's location. This data will allow a close-in search in the DQRMer's area and, using local transmitter hunting devices, the offender will be identified. This is a real-time system that's been in development for several years; its first major test will be the 2015 K1N Navassa DXpedition. WHAT YOU DO: Fill out the form with as much information as you can provide. All information will remain confidential. The form will go into a database and the DQRM Project software will do the rest. We can stop DQRM - and you can help! Doug There are some ideas so absurd that only an intellectual or lawyer could believe them. - George Orwell, 1984 --- This email has been checked for viruses by Avast antivirus software. http://www.avast.com _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Missing K1N 160m QSO records just uploaded to Clublog
Well, Tree, I think you might make a good case for a duplicate contact! My 160 QSO disappeared for a while, but eventually re-appeared! GL!\ 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Tree Sent: Friday, February 06, 2015 12:58 PM To: Art Snapper Cc: Bud Semon N7CW; 160 Subject: Re: Topband: Missing K1N 160m QSO records just uploaded to Clublog KV4FZ reported that K1N sounded like K1N during this night - so I am pretty sure it was not a pirate. Hopefully - this will get resolved at some point soon. Just good to know I am not alone. Thanks. Tree N6TR On Fri, Feb 6, 2015 at 9:53 AM, Art Snapper a...@nk8x.net wrote: Ditto. Wondering about Pirates of the Caribbean. On Fri, Feb 6, 2015 at 12:52 PM, Bud Semon N7CW n...@cableone.net wrote: Mine neither. 1027Z on 4 Feb. 73, Bud N7CW On Fri, Feb 6, 2015 at 10:46 AM, Tree t...@kkn.net wrote: This is good news - but still not seeing my call or ZL3IX who worked him just before me. QSO was around 0930 on 4 Feb UTC. Others??? Tree N6TR On Fri, Feb 6, 2015 at 9:40 AM, Lloyd Berg N9LB lloydb...@charter.net wrote: All, They just uploaded the missing K1N 160m QSO records to Clublog site a few minutes ago. ~ 7000 entries! ... including my missing 160m QSO :-) 73 Lloyd - N9LB _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Missing K1N 160m QSO records just uploaded to Clublog
Yeah- I saw that Tree's 160 QSO is back in log now. Maybe yours is there? 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Dave Clouser Sent: Friday, February 06, 2015 1:16 PM To: topband@contesting.com Subject: Re: Topband: Missing K1N 160m QSO records just uploaded to Clublog Mine is missing from 2/4 @ 1121z. :-( Hope it wasn't a pirate. Op this morning was saying no dupes 73 Dave NZ3M On 2/6/2015 1:01 PM, Ronald Gorski wrote: Many 160m Q's from 4 Feb still missing from upload made a few minutes ago. Ron N9AU -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Lloyd Berg N9LB Sent: Friday, February 06, 2015 11:41 AM To: topband@contesting.com Subject: Topband: Missing K1N 160m QSO records just uploaded to Clublog All, They just uploaded the missing K1N 160m QSO records to Clublog site a few minutes ago. ~ 7000 entries! ... including my missing 160m QSO :-) 73 Lloyd - N9LB _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: K1N On Line Log
Well, we did survive just fine, Eddy and lots of folks mad the Honor Roll, 5BDXCC etc.. All this nonsense about the online logs is just so much Bull!!! Can all be avoided if folks would do the following:\ 1.0 COPY your own call!!! No guesswork, no fragments, no bluffing etc. 2.0 Copy your report 3.0 Reply with your call, followed by an acknowledgement of DX Station Report (TU or thanks) and Send report to DX station followed (or preceded) by Thanks or TU 4.0 LISTEN for the DX operator to acknowledge your report 5.0 Thanks or TU -or even dit-dit Do those things completely and there won't be much guessing or wondering if you had a legitimate QSO that's logged!! We may have to have some patience and perseverance to work through the jammers, and QRM and the packet-rats tuning up on the DX QRG! It may be reassuring to see the online logs, but we should KNOW if we had a good contact or not! WITHOUT a computer to tell us we did!! I KNEW that my 7 QSOs with K1N were there BEFORE the logs came out! And NO DUPES or INSURANCE CONTACTS!Just my $0.02. 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Eddy Swynar Sent: Friday, February 06, 2015 3:17 PM To: topband@contesting.com Subject: Re: Topband: K1N On Line Log How did we EVER collectively survive the dark ages of hardcopy QSL cards, s.a.s.e.'s, QSL bureaus, DX news sheets, and I.R.C.s, I wonder...? Is everyone that impatient while attempting to WORK a rare station, too...? All this angst and trepidation being displayed here...! I thought DX'ing, Ham radio, Topband were all supposed to be FUN, and not a hand-wringing exercise in anger worry management... ~73~ de Eddy VE3CUI - VE3XZ _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: K1N what time are they QRV on top?
Hi, Herb Did you work K1N on 1817.5 this evening? 73, Charlie, K4OTV -Original Message- From: Charlie Cunningham [mailto:charlie-cunning...@nc.rr.com] Sent: Friday, February 06, 2015 7:59 PM To: 'Herbert Schoenbohm'; 'topband@contesting.com' Subject: RE: Topband: K1N what time are they QRV on top? Right now, Herb. 1817.3 up a couple. 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Herbert Schoenbohm Sent: Friday, February 06, 2015 5:41 PM To: topband@contesting.com Subject: Re: Topband: K1N what time are they QRV on top? They are normally very active on 160 from their local sunset to sunrise each day so far. Herb, KV4FZ On 2/6/2015 6:03 PM, Mike Coreen Smith VE9AA wrote: OK, finally, Friday has arrived and although I have a new one on 14MHz from the car (on my way to work) , I don't yet have it on TOP. My house radio has been off since the SSB Sprint. Are they following any kind of schedule for 160m? What time would be a good time to get on from the East Coast of NA? Thanks all GL in the fray. Mike VE9AA Mike, Coreen Corey Keswick Ridge, NB _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: K1N antenna
They may still be using that dipole hanging from the lighthouse, Art! I don't know that for sure, but thepy had BIG 160 signals when I worked the early in the week on 160. I understand that t he;y have been installing Beverages for receiving. That dipole was more or less vertical from what I could see in the photos! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Art Snapper Sent: Friday, February 06, 2015 4:42 PM To: 160 Subject: Topband: K1N antenna I couldn't find what they were using for a vertical on the topband. Anyone know? Or are they still using the dipole? Art _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: K1N what time are they QRV on top?
Right now, Herb. 1817.3 up a couple. 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Herbert Schoenbohm Sent: Friday, February 06, 2015 5:41 PM To: topband@contesting.com Subject: Re: Topband: K1N what time are they QRV on top? They are normally very active on 160 from their local sunset to sunrise each day so far. Herb, KV4FZ On 2/6/2015 6:03 PM, Mike Coreen Smith VE9AA wrote: OK, finally, Friday has arrived and although I have a new one on 14MHz from the car (on my way to work) , I don't yet have it on TOP. My house radio has been off since the SSB Sprint. Are they following any kind of schedule for 160m? What time would be a good time to get on from the East Coast of NA? Thanks all GL in the fray. Mike VE9AA Mike, Coreen Corey Keswick Ridge, NB _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: K1N On Line Log
I certainly agree with your final point, Mike! Amen! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Michael Walker Sent: Friday, February 06, 2015 10:35 AM To: topband@contesting.com Subject: Re: Topband: K1N On Line Log I agree that online logs are more of a problem than they are worth. The overhead on the DXpedition is just one more thing they need to worry about and staff for. This is a great example of how it increases the q rate for them and allowing others not to make a contact. If they must, then they shouldn't post the logs until they know they are 100% accurate as it does cause even more confusion. I also know I made a 160 contact with them and my entry is not in the log (yet). But, I am not going to try to work them again as I am confident of my contact and it only prevents others from making a contact. This is ham radio and we need to ensure that it was a quality contact on the air, not backing it up online. my 2 cents mike va3mw On Fri, Feb 6, 2015 at 10:26 AM, W3AW via Topband topband@contesting.com wrote: Agree, thanks for not making multiple contacts. Working K1N on 160 with my Index Labs Qrp Plus is a challenge. Kirk W3AW -- Original message-- From: Tom Haavisto Date: Thu, Feb 5, 2015 10:24 PM To: Doug Renwick; Cc: TopBand List; Subject:Re: Topband: K1N On Line Log The way I look at it, I got them on 80/160, so anything else is a bonus. There is still lots of time, so it might be best to wait for a day or two before looking for insurance Q's while Clublog gets sorted out. For me, I would really, really hate to have an insurance Q end up costing someone else their one any only chance at putting K1N in the log. Tom - VE3CX On Thu, Feb 5, 2015 at 11:10 PM, Doug Renwick wrote: Tonight the K1N on line log came back on. For me I lost a bunch of Qs that were there before, and some Qs I had made previously still didn't show. So I decided to work them again on 80 and 160 just to make sure. I am not sure what the problem is but a lot of folks are unhappy. In time it will be sorted out but in the meantime it does not cast a good light on an excellent operation. Doug There are some ideas so absurd that only an intellectual or lawyer could believe them. - George Orwell, 1984 --- This email has been checked for viruses by Avast antivirus software. http://www.avast.com _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: K1N On Line Log
Hi, Jim Well, it was a bit of a wait, but all 6 of my QSOs are back online now, including 160. I also got 'em on 80 and 160 - but - wonder of wonders - I wkd 'em on 160 fairly quickly on 160 with my 80m GP that, at the moment has only one radial! I've been off the air for a while struggling with a bout of MS - that's better now. My antennas are a mess and need some work and my beat-up old antenna tuner needs some repairs also. So, I'm a happy camper and glad that Navassa is close and the path loss is not so bad! Glad the logs are back on line! With the zoo of packet-rat tuners and the deliberate jammers, it's nice to get log confirmation online - but of course we didn't have that in the old days of hunt pounce and paper logs! Glad your Qa are back online! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Jim Brown Sent: Friday, February 06, 2015 12:41 AM To: topband@contesting.com Subject: Re: Topband: K1N On Line Log On Thu,2/5/2015 8:24 PM, Tom Haavisto wrote: The way I look at it, I got them on 80/160, so anything else is a bonus. Chiil -- there were some Qs that got logged on the wrong band, so they started from scratch, reloading to ClubLog. My 160 and 40 Q went away, now all six are there. 73, Jim K9YC _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: K1N last night
You may be right, Tree. My 160 QSO is in there, but I worked them night before last with my 80m GP with ONE radial! What a surprise! Just thought I'd hoot at 'em because they had such a good signal here in NC. It took my 12m and 15 m QSOs another day to show up! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Tree Sent: Thursday, February 05, 2015 12:53 AM To: 160 Subject: Topband: K1N last night Appears none of the 160 meter QSOs from last night (Feb 4) were included in the recent log update. Hopefully - it was really them last night. Tree N6TR _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: [Bulk] Top Loading wires
T hanks for the correction, Stan. My old eyes missed that!! A 90' tower won't require much top-loading at all! Sorry for my error 73, Charlie, K4OTV -Original Message- From: Stan Stockton [mailto:wa5...@gmail.com] Sent: Wednesday, February 04, 2015 1:41 PM To: Charlie Cunningham Subject: Re: Topband: [Bulk] Top Loading wires It's a 90 foot tower he is describing. Sent from my iPad On Feb 4, 2015, at 12:11 PM, Charlie Cunningham charlie-cunning...@nc.rr.com wrote: Gee, I surely agree with Grant, Larry! I've used EZNEC for MANY years, with great results, and I've designed, built, tested and measured many wonderful EZNEC designs - including some really complex killer antennas! I do think that 28' top loading wires will be WAY TOO SHORT atop 50 ft. of Rohn 25! More like 50-70' will be needed to resonate that tower. You will probably do just as well with TWO top-loading wires in a Tee configuration! The point is for the top-loading wires to extend the tower to 1/4 wave resonance on 160. Of course you could make an excellent 80m antenna with the 50' tower and some modest top-loading wires approaching the length that you are considering. GL! If you are going to be experimenting with low-band antennas, EZNEC is a GREAT investment 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Grant Saviers Sent: Wednesday, February 04, 2015 11:28 AM To: Larry - K1UO; Topband Reflector Subject: Re: Topband: [Bulk] Top Loading wires With an insulated tower, the cheapest EZNEC and other free NECs will yield good results. Would you rather climb, cut, and trim a few times or spend $89 to get EZNEC? Simple to learn. And the demo version is free eznec.com Grant KZ1W no affiliation, just a long term happy user On 2/4/2015 7:27 AM, Larry - K1UO wrote: Could someone tell me the length of top loading wires (4 wires planned) needed to add to the top of a base insulated 90 foot Rohn 25g tower to maximize the radiation resistance on 160 meters. I understand there is a point of diminishing returns on the top loading lengths. The 4 wire angles will be around 45 degrees or as close as possible.If I knew how to model ,or even had a modeling program, I would attempt this already relatively simple task to many. From 50+ years of practical experience, I am ‘guessing’ maybe 28 feet long each? _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: AC line bypass capacitors
Hi, Harold - well it's been a while, I know that we regularly used line bypasses in electricity meter and they had to be really robust, but I was mostly and RF and communications guy and when I had to fool with power supply designs for the meters, I generally just copied whatever was done before. Of course out there on the line side of the meter is a hellish surge environment. On guy mentioned film capacitors, but I would be a bit skeptical of those as RF bypasses. The capacitors that we used were very robust, as they had to withstand 480 volt high-line voltage or 530 VAC. And yes I have seen my share of fried line bypass capacitors in consumer electronics and radio gear. 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of HAROLD SMITH JR Sent: Wednesday, February 04, 2015 9:16 PM To: Charlie Cunningham; 'Paul Christensen'; topband@contesting.com Subject: Re: Topband: AC line bypass capacitors Hi Charlie, I can remember when the Collins S-Line used .01 600volt disk ceramic capacitors on the power supply connector. They were from the AC switch to ground. They were almost always burnt and many times only the leads left. 73 Price W0RI On Wednesday, February 4, 2015 6:31 PM, Charlie Cunningham charlie-cunning...@nc.rr.com wrote: Hi, Paul For AC line bypass capacitors look for UL-rated Ceramic Disc capacitors that typically have AC working voltages like 250 VAC or higher. These are designed and rated for AC line service and can take the surges that occur on AC lines. Check Digi-Key, Newark and others - you'll find plenty! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Paul Christensen Sent: Wednesday, February 04, 2015 3:55 PM To: topband@contesting.com Subject: Re: Topband: AC line bypass capacitors My 160 TX is causing RFI to one of my baseboard heater programmable thermostats (switches modes, temperature, when I transmit). The thermostat has a 2 wire connection to 240VAC in a metal receptacle box that has a third wire common ground wire. I would like to try bypassing the AC line. Can someone suggest an appropriate (safe) capacitor for this purpose, e.g. a Digi-Key or Mouser part number? Should I use one capacitor across the 240VAC or two capacitors, one from each 120VAC line to the common wire? Thanks for the help. _ As a substitute for X1 Y2 line caps, an in-line RFI/EMI filter can be used that already contains the X/Y-rated caps. See the bottom of p. 21: http://audiosystemsgroup.com/RFI-Ham.pdf These filters can often be cannibalized from old PC power supplies and discarded industrial equipment. Paul, W9AC _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: AC line bypass capacitors
Hi, Paul For AC line bypass capacitors look for UL-rated Ceramic Disc capacitors that typically have AC working voltages like 250 VAC or higher. These are designed and rated for AC line service and can take the surges that occur on AC lines. Check Digi-Key, Newark and others - you'll find plenty! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Paul Christensen Sent: Wednesday, February 04, 2015 3:55 PM To: topband@contesting.com Subject: Re: Topband: AC line bypass capacitors My 160 TX is causing RFI to one of my baseboard heater programmable thermostats (switches modes, temperature, when I transmit). The thermostat has a 2 wire connection to 240VAC in a metal receptacle box that has a third wire common ground wire. I would like to try bypassing the AC line. Can someone suggest an appropriate (safe) capacitor for this purpose, e.g. a Digi-Key or Mouser part number? Should I use one capacitor across the 240VAC or two capacitors, one from each 120VAC line to the common wire? Thanks for the help. _ As a substitute for X1 Y2 line caps, an in-line RFI/EMI filter can be used that already contains the X/Y-rated caps. See the bottom of p. 21: http://audiosystemsgroup.com/RFI-Ham.pdf These filters can often be cannibalized from old PC power supplies and discarded industrial equipment. Paul, W9AC _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: 160m Sloping Vertical Antenna?
Multi-path was my thought as well! Merry Christmas! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Tom W8JI Sent: Thursday, December 25, 2014 11:02 AM To: Richard (Rick) Karlquist; Art Roberts - W5AER; topband@contesting.com Subject: Re: Topband: 160m Sloping Vertical Antenna? More likely it was a mix of groundwave and sky wave, if the station was local, cancelling or reinforcing signal as phase shifted on the sky wave path. - Original Message - From: Richard (Rick) Karlquist rich...@karlquist.com To: Art Roberts - W5AER w5...@hotmail.com; topband@contesting.com Sent: Wednesday, December 24, 2014 9:23 PM Subject: Re: Topband: 160m Sloping Vertical Antenna? On 12/24/2014 3:39 PM, Art Roberts - W5AER wrote: On the thought of a low dipole: Years ago in Northern California, as an experiment, I had a VERY low dipole and got some strange results. Listening to a local station, in the afternoon, there was very deep QSB. We were able to talk, but with difficulty. 73, Art W5AER Were you cross polarized; IE was the other station running a vertical? If so, minor fluctuations in propagation could result in major fluctations of polarization cancellation. Rick N6RK _ Topband Reflector Archives - http://www.contesting.com/_topband - No virus found in this message. Checked by AVG - www.avg.com Version: 2014.0.4794 / Virus Database: 4253/8802 - Release Date: 12/24/14 _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: 160 Shunt-Fed Tower Readings
From your description and your measured data, Larry, I don't see how you could improve the antenna noticeably! Why do you feel a need to improve it? I appears to be resonant, well-matched and it appears to have an excellent ground image system! I think you might be kidding yourself if you change anything! As the old adage says n If it ain't broke -don't fix it! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Larry K4AB Sent: Wednesday, December 10, 2014 2:41 PM To: topband@contesting.com Subject: Topband: 160 Shunt-Fed Tower Readings The antenna is a 94' Rohn 25, with a Force 12 24'boom Delta 6BA on top. Note that the elements are insulated from the boom. The base of the tower is grounded. 73 radials are attached to the base ranging in length from 130'-250'. 15,000 feet of radials, average length of ~200'. It is fed through a series 1000pF 10KV Jennings vacuum variable. The shunt is a 4 wire cage about 3 in diameter and attached at ~45' level. It is spaced about 3' from the tower. Here are the readings I get from a RigExpert AA-30 at the feedpoint: 1.830 kHz Series model: lZI: 59.7 Ohms R:59.5 Ohms SWR: 1.23 X:5.6 Ohms C: 15893 pF What are these reading telling me,and how can I improve the antenna? Thanks, in advance! 73, Larry K4AB _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: 160 Shunt-Fed Tower Readings
Hi, again, Larry, Well, first of all the shunt feed, being a shorted transmission line, 1/4 wavelength in extent, would present an inductive resent at the feed point that you are correctly cancelling with the 1000 pF series variable capacitor. You missed ever so slightly and you are showing a series reactance of j5.6 ohms! Trivially small and negligible!! DON'T bother trying to improve it!! You would pick up more reactance than that by just changing frequency a few kilohertz!! It's PERFECT! The 15893 pF is the equivalent series capacitance that would produce -j5.6 ohms of capacitive reactance - so the message is that the equivalent series capacitance is NEGLIGIBILY LARGE!! (LARGE is GOOD!) If you had measured at a frequency where the reactance cancellatio was exact and perfect, the driving point impedance would be pure real, with 0 reactance that would correspond to infinite capacitance or 0 inductance. The real part of your driving point impedance is 59.5 ohms real, resulting in a VSWR od 1.23:1!! So near a perfect match that you won't improve it significantly, even if you did an AWFUL LOT of work to make a trivially small change in the tap point of your wire cage!! The mismatch loss at 1.23:1 VSWR is essentially 0, and the excess loss in a feedline operating at 1.23:1 VSWR is essentially 0, and the loss in even a very long run of coax would be essentially equal to the flat' loss - that is: the loss in a flat line operated at 1:1 VSWR. So, Larry, you've done a GREAT job on your TX antenna. And do keep in mind that you have 24 feet of boom up there that's top-loading that 94' of Rohn 25! Just congratulate yourself on a job well done, and ENJOY!! If you want to worki on topband antennas - work on Beverages or terminated loop receive antennas to help you HEAR better! Great job! Have fun and enjoy! BTW - I AM an RF engineer and I have spent q lot of my career designing and measuring antennas 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Larry K4AB Sent: Wednesday, December 10, 2014 6:14 PM To: Charlie Cunningham Cc: topband@contesting.com Subject: Re: Topband: 160 Shunt-Fed Tower Readings line Why do you feel a need to improve it? Thanks for the response, Charlie! I'm concerned about a few things: 1) I'm thinking the antenna is electrically too short. After all, the Yagi at the top really isn't adding too much top loading. And I'm thinking adding a couple of top loading wires connected to the tower might be beneficial. 2) What exactly is the analyzer telling me when it says C:15893pF? I'm far from an engineer, but something tells me that's way high. Or is it? 73, Larry K4AB On 12/10/14, Charlie Cunningham charlie-cunning...@nc.rr.com wrote: From your description and your measured data, Larry, I don't see how you could improve the antenna noticeably! Why do you feel a need to improve it? I appears to be resonant, well-matched and it appears to have an excellent ground image system! I think you might be kidding yourself if you change anything! As the old adage says n If it ain't broke -don't fix it! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Larry K4AB Sent: Wednesday, December 10, 2014 2:41 PM To: topband@contesting.com Subject: Topband: 160 Shunt-Fed Tower Readings The antenna is a 94' Rohn 25, with a Force 12 24'boom Delta 6BA on top. Note that the elements are insulated from the boom. The base of the tower is grounded. 73 radials are attached to the base ranging in length from 130'-250'. 15,000 feet of radials, average length of ~200'. It is fed through a series 1000pF 10KV Jennings vacuum variable. The shunt is a 4 wire cage about 3 in diameter and attached at ~45' level. It is spaced about 3' from the tower. Here are the readings I get from a RigExpert AA-30 at the feedpoint: 1.830 kHz Series model: lZI: 59.7 Ohms R:59.5 Ohms SWR: 1.23 X:5.6 Ohms C: 15893 pF What are these reading telling me,and how can I improve the antenna? Thanks, in advance! 73, Larry K4AB _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: 160 Shunt-Fed Tower Readings
N0!! That's the equivalent series capacitance that correspond to -j5.6ohms capacitive reactance! It would be much clearer if the analyzer would present it in that form, since it clearly has determined the sign - since it's indicating an equivalent capacitance. Anyway, I stand by what I wrote you, Larry. I'd leave that TX antenna alone! 59.5 ohms real with 1.23;1 vswr IS JUST FINE! IMO Have Fun! 73, Charlie, K4OTV From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Larry K4AB Sent: Wednesday, December 10, 2014 7:10 PM To: topband@contesting.com Subject: Re: Topband: 160 Shunt-Fed Tower Readings I would like to know how you can get 15893pf from a 1000pf capacitor. That has to be a mis-read value there...gary maybe rounded off to 159pf?? That's a great question. Where is the analyzer actually getting that reading? 73, Larry K4AB On 12/10/14, Tom W8JI w...@w8ji.com wrote: I'm concerned about a few things: 1) I'm thinking the antenna is electrically too short. After all, the Yagi at the top really isn't adding too much top loading. And I'm thinking adding a couple of top loading wires connected to the tower might be beneficial. If you run any power, you will likely start to have problems with arcing at the Yagi antenna elements where they cross the boom. This is because of the poor insulation, and because of the high voltage at the boom when on 160. The cure for that is to ground the elements to the boom though air coil inductors. Just five or ten uH would work OK, and not upset the antenna operation. This would also add 160 top loading. 2) What exactly is the analyzer telling me when it says C:15893pF? I'm far from an engineer, but something tells me that's way high. Or is it? It is meaningless. It just means you are measuring almost where the antenna is resonant. 73 Tom _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: 160 Shunt-Fed Tower Readings
You're quite welcome, Larry! Hope it helped! You're certainly on the right track and doing some good work! FB on the Beverages!! Wish I had real estate for beverages, but I live on a city lot, so I had to resort to terminated receiving loops that, surprisingly, worked quite well and enabled me to hear LOTS that I had been missing on 160. Generally, with my inverted-L and 500-600 watts, if I could hear 'em, I could work 'em! My problem before putting up the KAZ loops was hearing! The terminated loops were great receive antennas on 80, 40 and 30m also. The Beverages should help you a LOT! Have fun and have a Merry Christmas! 73, Charlie, K4OTV -Original Message- From: Larry K4AB [mailto:larry.k...@gmail.com] Sent: Wednesday, December 10, 2014 8:23 PM To: Charlie Cunningham Cc: topband@contesting.com Subject: Re: Topband: 160 Shunt-Fed Tower Readings TU, Charlie on a great explaination for us non-engineers! The topband reflector is a great resource for guys like me trying to understand this band, even after decades in the hobby. And yes, I'm working on the Beverages, as we speak! Thanks, again! 73, Larry K4AB On 12/10/14, Charlie Cunningham charlie-cunning...@nc.rr.com wrote: Hi, again, Larry, Well, first of all the shunt feed, being a shorted transmission line, 1/4 wavelength in extent, would present an inductive resent at the feed point that you are correctly cancelling with the 1000 pF series variable capacitor. You missed ever so slightly and you are showing a series reactance of j5.6 ohms! Trivially small and negligible!! DON'T bother trying to improve it!! You would pick up more reactance than that by just changing frequency a few kilohertz!! It's PERFECT! The 15893 pF is the equivalent series capacitance that would produce -j5.6 ohms of capacitive reactance - so the message is that the equivalent series capacitance is NEGLIGIBILY LARGE!! (LARGE is GOOD!) If you had measured at a frequency where the reactance cancellatio was exact and perfect, the driving point impedance would be pure real, with 0 reactance that would correspond to infinite capacitance or 0 inductance. The real part of your driving point impedance is 59.5 ohms real, resulting in a VSWR od 1.23:1!! So near a perfect match that you won't improve it significantly, even if you did an AWFUL LOT of work to make a trivially small change in the tap point of your wire cage!! The mismatch loss at 1.23:1 VSWR is essentially 0, and the excess loss in a feedline operating at 1.23:1 VSWR is essentially 0, and the loss in even a very long run of coax would be essentially equal to the flat' loss - that is: the loss in a flat line operated at 1:1 VSWR. So, Larry, you've done a GREAT job on your TX antenna. And do keep in mind that you have 24 feet of boom up there that's top-loading that 94' of Rohn 25! Just congratulate yourself on a job well done, and ENJOY!! If you want to worki on topband antennas - work on Beverages or terminated loop receive antennas to help you HEAR better! Great job! Have fun and enjoy! BTW - I AM an RF engineer and I have spent q lot of my career designing and measuring antennas 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Larry K4AB Sent: Wednesday, December 10, 2014 6:14 PM To: Charlie Cunningham Cc: topband@contesting.com Subject: Re: Topband: 160 Shunt-Fed Tower Readings line Why do you feel a need to improve it? Thanks for the response, Charlie! I'm concerned about a few things: 1) I'm thinking the antenna is electrically too short. After all, the Yagi at the top really isn't adding too much top loading. And I'm thinking adding a couple of top loading wires connected to the tower might be beneficial. 2) What exactly is the analyzer telling me when it says C:15893pF? I'm far from an engineer, but something tells me that's way high. Or is it? 73, Larry K4AB On 12/10/14, Charlie Cunningham charlie-cunning...@nc.rr.com wrote: From your description and your measured data, Larry, I don't see how you could improve the antenna noticeably! Why do you feel a need to improve it? I appears to be resonant, well-matched and it appears to have an excellent ground image system! I think you might be kidding yourself if you change anything! As the old adage says n If it ain't broke -don't fix it! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Larry K4AB Sent: Wednesday, December 10, 2014 2:41 PM To: topband@contesting.com Subject: Topband: 160 Shunt-Fed Tower Readings The antenna is a 94' Rohn 25, with a Force 12 24'boom Delta 6BA on top. Note that the elements are insulated from the boom. The base of the tower is grounded. 73 radials are attached to the base ranging in length from 130'-250'. 15,000 feet of radials, average length
Re: Topband: EZNEC 5.0 +
Thanks, Carl I suppose all those wires helped to increase bandwidth. Charlie K4OTV -Original Message- From: Carl [mailto:k...@jeremy.qozzy.com] Sent: Saturday, December 06, 2014 10:20 AM To: Charlie Cunningham; 'Paul Christensen'; 'topband' Subject: Re: Topband: EZNEC 5.0 + Charlie, visualize a straight horizontal wire wire between two tall points; then slanting to vertical wires coming down to the common feed point. The Titanic had a multi wire T horizontal and vertical fed in the center. Considering its daytime range of 200-400 miles and up to 2200 at night with about 500W radiated from a 5KW spark it was pretty effective on 600M. Carl KM1H - Original Message - From: Charlie Cunningham charlie-cunning...@nc.rr.com To: 'Paul Christensen' w...@arrl.net; 'topband' topband@contesting.com Sent: Saturday, December 06, 2014 12:41 AM Subject: Re: Topband: EZNEC 5.0 + Not sure that I can picture just what you are describing, Paul. Even though, I wasn't born until 1944, I've explored just about every type of antenna and I've modeled an awful lot of them. Of course the typical inverted L is just a monopole that is bent over at the top to reduce the required support height, and an inverted L with elevated radials is just a ground-plane antenna that is bent over at the top and the Tee equivalents just replace the single top wire with equal and opposite wires at the top to extend the monopole to resonant length. The Tee version does eliminate the modest residual horizontal component in the far field that occurs with the inverted L configuration. Of course antenna current is still fundamentally important - that's what does the radiation! I do still have a matched pair of RF ammeters around here, but these days we accomplish the equivalent measurement by measuring forward power with our SWR bridges. There's still a fundamental I-squared x R relation between power and antenna current, where R is the radiation resistance of the antenna + copper losses. So, it's all the same thing, really. I can't come up with the name of the antenna that you are describing, because I can't quite picture it. 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Paul Christensen Sent: Friday, December 05, 2014 11:23 PM To: topband Subject: Re: Topband: EZNEC 5.0 + What did they call the teens to 20's antenna that had multiple feeds coming down from one end of the flatop to the other? Both the T and the fanned inverted L were popular on 200m in 1910-1920 just as the single-wire Inverted L is today on 160m. Back then, ops were obsessed with maximum antenna current but radiation resistance didn’t enter into the discussions until the mid '20s. By the mid 20s when CW took over, much less attention was paid to antenna current as a station performance metric. During the spark era, ops would keep adding horizontal wires to the flat top fans until the line current reached diminishing returns. We typically see 5-6 wires wide-spread in old station photos.Then, separate wires would connect to the flat top and extended down a common point where it became a single-wire feeder. Paul, W9AC _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband - No virus found in this message. Checked by AVG - www.avg.com Version: 2015.0.5577 / Virus Database: 4235/8690 - Release Date: 12/06/14 _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: EZNEC 5.0 +
Hi, Chuck Well return loss is a transmission line term that is a measure of the reflection on the line. So a transmission line that is terminated in its characteristic impedance would have 0 reflection, or infinite return loss or 1.0:1 VSWR. Conversely if the line was lossless and terminated in an open or a short, 100% of the incident power would be reflected, resulting in 0dB return loss, or infinite VSWR. So you want to target the lowest VSWR - as close to 1.0:1 as possible. BTW, it can be shown in the general case, that minimum VSWR will occur at RESONANCE. Have fun with EZNEC, it's a wonderful, powerful, and easy to use program that have used over the years to model,design and build some wonderful killer antennas that have performed wonderfully! Have fun and keep learning! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Charles Yahrling Sent: Friday, December 05, 2014 3:29 PM To: topband@contesting.com Subject: Topband: EZNEC 5.0 + Just getting started modelling and looking for answers to questions not found in manual so far. For example, what exactly is included in the Return Loss figure shown in the SWR window? Just ground reflection loss, total system loss, something else? Trying to understand why Return Loss is greater for lower SWR curve values. e.g see this when toggling between std and alt impedance. What is this suggesting, go with lower return loss or lower swr curve? An incomplete grasp of the fundamentals is admittedly likely here g. 73, chuck -- de AB1VL NAQCC #6799 ab1vl.com _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: EZNEC 5.0 +
Well, I would respectfully disagree with Tom, that Return Loss is confusing or ,misleading. It's just another way of looking at reflections that often makes more sense of is more useful. For example, many filters etc. are specified in terms of their input return loss, usually in a 50 ohm system,and engineers working in the lab with vector network analyzers measure most all input matches in terms of return loss. On a Smith Chart, return-loss is a radially scaled parameter, as is VSWR. The origin of the chart, at a perfect match would be the 1:1 VSWR point,or the infinite return loss point. Conversely, the perimeter of the chart corresponds to 0 return loss or infinite VSWR. EZNEC and network analyzers tend to express things in terms of return-loss, although VSWR is also available. For modeling in EZNEC and tuning or sweeping your antenna models,you want to MAXIMIZE return loss and MINIMIZE VSWR- it's the same thing. As an example to illustrate Tom's point. IF we fed a resonant 1/2 Wave dipole at its center, with 600 ohm open-wire line, the VSWR on the feedline would approach 10:1, but there would be almost no loss in the feedline and virtually 100% of the incident power would be radiated by the antenna. The challenge would be to match the transmitter to whatever values of R+JX presented themselves at the sending end of the line. Have fun with EZNEC! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Tom W8JI Sent: Friday, December 05, 2014 4:40 PM To: Charles Yahrling; topband@contesting.com Subject: Re: Topband: EZNEC 5.0 + Return loss is just another misleading confusing way to express SWR. Return loss, like percentage reflected power, does not indicate any type of loss. It just expresses SWR in a different form. We can have 10:1 SWR, which would be a 1.743 dB return or mismatch loss or 67% reflected power, and still have virtually no loss. We can have 67% reflected power and still have nearly 100% of transmitter power getting into the antenna and being radiated. The best advice is to ignore it all, and just use SWR for now. :) - Original Message - From: Charles Yahrling cfytech2...@gmail.com To: topband@contesting.com Sent: Friday, December 05, 2014 3:29 PM Subject: Topband: EZNEC 5.0 + Just getting started modelling and looking for answers to questions not found in manual so far. For example, what exactly is included in the Return Loss figure shown in the SWR window? Just ground reflection loss, total system loss, something else? Trying to understand why Return Loss is greater for lower SWR curve values. e.g see this when toggling between std and alt impedance. What is this suggesting, go with lower return loss or lower swr curve? An incomplete grasp of the fundamentals is admittedly likely here g. 73, chuck -- de AB1VL NAQCC #6799 ab1vl.com _ Topband Reflector Archives - http://www.contesting.com/_topband - No virus found in this message. Checked by AVG - www.avg.com Version: 2014.0.4794 / Virus Database: 4235/8686 - Release Date: 12/05/14 _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: EZNEC 5.0 +
Not sure that I can picture just what you are describing, Paul. Even though, I wasn't born until 1944, I've explored just about every type of antenna and I've modeled an awful lot of them. Of course the typical inverted L is just a monopole that is bent over at the top to reduce the required support height, and an inverted L with elevated radials is just a ground-plane antenna that is bent over at the top and the Tee equivalents just replace the single top wire with equal and opposite wires at the top to extend the monopole to resonant length. The Tee version does eliminate the modest residual horizontal component in the far field that occurs with the inverted L configuration. Of course antenna current is still fundamentally important - that's what does the radiation! I do still have a matched pair of RF ammeters around here, but these days we accomplish the equivalent measurement by measuring forward power with our SWR bridges. There's still a fundamental I-squared x R relation between power and antenna current, where R is the radiation resistance of the antenna + copper losses. So, it's all the same thing, really. I can't come up with the name of the antenna that you are describing, because I can't quite picture it. 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Paul Christensen Sent: Friday, December 05, 2014 11:23 PM To: topband Subject: Re: Topband: EZNEC 5.0 + What did they call the teens to 20's antenna that had multiple feeds coming down from one end of the flatop to the other? Both the T and the fanned inverted L were popular on 200m in 1910-1920 just as the single-wire Inverted L is today on 160m. Back then, ops were obsessed with maximum antenna current but radiation resistance didn’t enter into the discussions until the mid '20s. By the mid 20s when CW took over, much less attention was paid to antenna current as a station performance metric. During the spark era, ops would keep adding horizontal wires to the flat top fans until the line current reached diminishing returns. We typically see 5-6 wires wide-spread in old station photos.Then, separate wires would connect to the flat top and extended down a common point where it became a single-wire feeder. Paul, W9AC _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: [time-nuts] Minicircuits 10% discount in December
I had good results with a matching transformer for 50-800 ohms for a terminated KAZ receiving loop, that was wound on a binocular core of 73 material. Very modest turn count. I wound it as a conventional transformer with wire-wrap wire to accommodate the small core. The loop worked VERY well on 160, 80, 40 and 30m. I could hear lots on 160 that I hadn't even known was there before putting up the loop! It was a huge help on 160 on my small lot. The loop was terminated with an 820 ohm carbon composition resistor. 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Tom W8JI Sent: Thursday, November 27, 2014 7:20 PM To: topband@contesting.com Subject: Re: Topband: [time-nuts] Minicircuits 10% discount in December Anyone with proper test equipment can measure and verify what I say below is absolutely true. I'd hate to see anyone accept this information as factual or accurate: The single turn resonance of this core is around 10 MHz, with a Z at resonance of about 120 ohms. Like any other ferrite core, winding turns will increase L as N squared, increase C as N, thus moving the resonance down in frequency. I'd guess that 8 turns would move the resonance fairly close to 160M with Z in the range of 4-5K ohms. The catch is that the i.d. is pretty small, so the choke would need to be wound with something like one pair out of CAT5 cable. 10 MHz is the core resonance, not the combination of winding inductance and winding capacitance. Somewhere around 10 MHz the core, no matter how many turns are wound, crosses from having any inductive effects to capacitive. This is because the core becomes diamagnetic, not because of the winding. The dominant impedance anywhere above 2-3 MHz is resistive. If you wind one pass around the center (out and back to start through both holes) you'll find the reactive sign of core impedance crosses over to capacitance at around 10 MHz. If you wind five turns, it remains about the same. The capacitance effect does not matter much because core resistance dominates. As turns are added, the resistance shunting the winding increases with only a slight shifting of apparent resonance. It is the resistance that dominates and parallels the windings. The loading effect can be minimized by proper winding techniques. This core (or any 73 material) reaches X = R, or Q = 1, at around 2.5 MHz. In other words, at around 2.5 MHz, one pass (through the hole and back to start) is about 75 +j75 ohms, where inductance and resistance are equal. You want at least a two-pass (out and around and back two times) 50-75 ohm winding for 160 meters, and it will be good well beyond 30 MHz. Fair-Rite considers this a suppression part, not an inductive part, although it is widely used for winding transformers for MF RX antennas. The laws of physics don't change with what we call something, so this will be a fairly lossy transformer. The last sentence is incorrect. A typical primary-secondary modest impedance broadband transformer using that core, with minimal attention to winding style, has about 1 dB loss at 50 MHz. Loss decreases with a reduction in frequency, and is a fraction of a dB on 2 MHz. Without special care, this transformer material is easily much less than .5 dB loss across HF. With higher power you might have to move to a lower loss core, or with very high impedances you may want to choose a core that allows the winding to become resonant, but characterizing this core as fairly lossy (whatever that really means) is not correct unless we consider 1/2 dB fairly lossy. Generally, 1/2 dB (10% power loss) core loss becomes worrisome with a core this size at about 10-20 watts. At 20 watts the core will be dissipating about 2 watts on HF, less at the low end of HF or on 160 meters. At higher power, the core loss over the operating frequency range has to decrease or the size increase. The ALS1306, for example, uses a stack of 43 mix cores just like this style for the input transformer. That transformer has less than .2 dB loss from 1.8 to 100 MHz, and safely handles well over 100 watts. For receive, and if extreme impedances are not required, the 73 mix core is good to 60 MHz or so. For RX transformers, it may not matter (and the low Q may even help), but don't be surprised when you see the added resistance beyond what the turns ratio predicts. :) You will see a loading effect in high impedance applications, because even several thousand ohms core resistance shunting a winding will load a 400 ohm or higher resistance load. Broadband transformers almost always use a core material that is well beyond magnetic effects at the top end of the frequency range. That is what makes them broadband. 73 Tom _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Broadband Inverted L
Hi, Joe I didn't have time to write you earlier. It was obvious that you had a lot of ground loss in series with the radiation resistance of the inverted-L that was swamping the reactance variation of the inverted L. You are likely to be very pleasantly surprised at how effective two elevated resonant radials at 5-6' can be! I did that for years - worked JA, VKs, VK6, JT1, S79,many deep European and Russians, lots of, LOTs of Pacific and DXpeditons etc.. Of course you can also lay out some more radials from your feed-point! Good luck! Have fun! The taller vertical section will help a lot! Mine was about 75 feet! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Joe Galicic Sent: Thursday, November 20, 2014 2:12 PM To: Mike Waters Cc: List, TopBand Subject: Re: Topband: Broadband Inverted L Thanks everyone ! Interesting. I knew something was not quite right. I thought I could tap into the existing ground system but obviously that is not going to be the case. I could manage two elevated radials pretty easily but not at 10 ten feet. More like 6 feet off the ground mounted on my 6 foot high wooden privacy fence. Can I lay down radials more over top of the old ones? - Original Message - From: Mike Waters mikew...@gmail.com To: List, TopBand topband@contesting.com Sent: Thursday, November 20, 2014 1:23:32 PM Subject: Re: Topband: Broadband Inverted L Have you considered elevated radials? Four of them 10' high (or even two!) would be MUCH better than what you have right now. My 160m Inverted-L: http://www.w0btu.com/160_meters.html#inv-l_antenna 73, Mike www.w0btu.com _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: FW: Balun or no balun
That loop might do better for DX if you fed it 1/2 way up one end. 73, Charlie, K4OTV -Original Message- From: Charlie Cunningham [mailto:charlie-cunning...@nc.rr.com] Sent: Tuesday, November 11, 2014 12:54 AM To: 'W3AW' Subject: RE: Topband: Balun or no balun Why the 30' of ladder line? Why not just run coax to the loop and put a 1:1 current balun at the feed point. A bit of VSWR on the coax wouldn't produce any significant loss in 50' of coax at 160m! Of course, if you want to use a balanced line tuner , that's another matter. 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of W3AW via Topband Sent: Monday, November 10, 2014 11:47 PM To: topband@contesting.com Subject: Topband: Balun or no balun I have put up a 160 meter horizontal loop fed with 30 feet of 450 ohm feed line to my tuner. I have a Radioworks 4 to 1 balun. I am considering splicing into the feed line at 10 feet so I can run 20 feet of coax into the shack. Thoughts? I run a qrp plus on 160. Kirk W3AW Illinois _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Legality of Circumventing Commercial Maritime ISP Services??
Well, that is exactly what it's all about, Dan!! Some of us need to press those points really hard with FCC and ARRL! They are trying to usurp our amateur spectrum for commercial and monetary purposes And it really IS about the maritime services!! They are wanting to provide Internet services in the amateur bands for commercial and monetary purposes. 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Dan White Sent: Saturday, March 15, 2014 10:49 PM To: topband@contesting.com Subject: Topband: Legality of Circumventing Commercial Maritime ISP Services?? Yachtsmen may be using amateur radio in order to avoid paying the fees for more expensive maritime email systems, perhaps such as http://www.sailmail.com/ , which charges an annual vessel fee of $250. This is most certainly a radio service. Winlink on the other hand, operates under Part 97 of FCC Regulations. They market themselves to boat owners for maritime use. See http://www.winlink.org/node/233 for details. My question is simple and legitimate. After reading FCC Part 97.113 which deals with Prohibited Amateur Communications, the rules specifically state routine communications are prohibited in cases where other radio services are available. Are the yachtsmen using email servers operating within our amateur spectrum in compliance with FCC Part 97.113? FCC Part 97.113 a: No amateur station shall transmit, (5)Communications, on a regular basis, which could reasonably be furnished alternatively through other radio services. 73, Dan W5DNT _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Passive Receive Antenna Splitter
Yeah, that's why I cautioned Gary about using CATV splitters at 160m. Seems that he has enough reserve gain with his Beverage and K3, that he could certainly tolerate the loss of a 50 ohm resistive splitter. The design of those is simple and he surely should be able to tolerate the 3.5 dB or so of splitter loss. 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carl Sent: Friday, March 14, 2014 10:41 AM To: Charlie Cunningham; garyk...@wi.rr.com; 'Topband Mailing List' Subject: Re: Topband: Passive Receive Antenna Splitter All the TV splitters Ive taken apart are pure autotransformers with poor isolation. A VNA will show them deterioating and doing very little at 160M. It is simple enough to wind transformers for a splitter using 1/2 type 43 toroids. See this link that gives an excellent discussion and also shows the cheap way of doing it and the better way. Guess what is used in consumer grade CATV versions. http://www.minicircuits.com/app/AN10-006.pdf Both versions have been in handbooks for decades and I first started using them with Beverages in the mid 80's. Ive also used them as combiners and connecting various combinations of 2 Beverages with some very beneficial performance at times. Port to port isolation was very important to me. There are also several other on line versions, good and bad, if you do a Goggle for how to make a 2 way 50 ohm splitter Carl KM1H - Original Message - From: Charlie Cunningham charlie-cunning...@nc.rr.com To: garyk...@wi.rr.com; 'Topband Mailing List' topband@contesting.com Sent: Thursday, March 13, 2014 9:41 PM Subject: Re: Topband: Passive Receive Antenna Splitter One word of caution, Gary, if the CATV splitter is a transformer type, rather than resistive it may of have enough low-frequency response for 160 m! Check around with RS and your local electronics stores for 50 ohm 2-way splitters. Those are generally resistive and have frequency response from DC up to a GHz or so. Some of the TV stuff is transformer coupled. 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Gary K9GS Sent: Thursday, March 13, 2014 9:14 PM To: Topband Mailing List Subject: Topband: Passive Receive Antenna Splitter Can anyone point me to a design for a splitter for sharing a Beverage antenna between two receivers? This is for Field Day so these are not optimized Beverages by any means. Just want to allow the 80/40M stations to share antennas. Nothing fancy. My thoughts are to just use a CATV 2-Way splitter at the output of the Beverage matching transformer and run separate feed-lines to each radio. I'm pretty sure these things work down to 1 MHz but have not measured them. I can use the pre-amp in the radio (K3) to compensate for the loss. Thoughts? -- 73, Gary K9GS Greater Milwaukee DX Association: http://www.gmdxa.org Society of Midwest Contesters: http://www.w9smc.com CW Ops #1032 http://www.cwops.org _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband - No virus found in this message. Checked by AVG - www.avg.com Version: 2014.0.4336 / Virus Database: 3722/7192 - Release Date: 03/13/14 _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Passive Receive Antenna Splitter
That should work fine, Gary! You would have around 3 dB loss in a two-way splitter + a SMALL amount of mismatch-loss for the 50-75 ohm mismatch. I would expect that if your radio will work with the beverage signal, you won't likely need the preamp to make up for tha very modest loss from the splitter and the 75-50 ohm mismatch! Should work fine! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Gary K9GS Sent: Thursday, March 13, 2014 9:14 PM To: Topband Mailing List Subject: Topband: Passive Receive Antenna Splitter Can anyone point me to a design for a splitter for sharing a Beverage antenna between two receivers? This is for Field Day so these are not optimized Beverages by any means. Just want to allow the 80/40M stations to share antennas. Nothing fancy. My thoughts are to just use a CATV 2-Way splitter at the output of the Beverage matching transformer and run separate feed-lines to each radio. I'm pretty sure these things work down to 1 MHz but have not measured them. I can use the pre-amp in the radio (K3) to compensate for the loss. Thoughts? -- 73, Gary K9GS Greater Milwaukee DX Association: http://www.gmdxa.org Society of Midwest Contesters: http://www.w9smc.com CW Ops #1032 http://www.cwops.org _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Passive Receive Antenna Splitter
One word of caution, Gary, if the CATV splitter is a transformer type, rather than resistive it may of have enough low-frequency response for 160 m! Check around with RS and your local electronics stores for 50 ohm 2-way splitters. Those are generally resistive and have frequency response from DC up to a GHz or so. Some of the TV stuff is transformer coupled. 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Gary K9GS Sent: Thursday, March 13, 2014 9:14 PM To: Topband Mailing List Subject: Topband: Passive Receive Antenna Splitter Can anyone point me to a design for a splitter for sharing a Beverage antenna between two receivers? This is for Field Day so these are not optimized Beverages by any means. Just want to allow the 80/40M stations to share antennas. Nothing fancy. My thoughts are to just use a CATV 2-Way splitter at the output of the Beverage matching transformer and run separate feed-lines to each radio. I'm pretty sure these things work down to 1 MHz but have not measured them. I can use the pre-amp in the radio (K3) to compensate for the loss. Thoughts? -- 73, Gary K9GS Greater Milwaukee DX Association: http://www.gmdxa.org Society of Midwest Contesters: http://www.w9smc.com CW Ops #1032 http://www.cwops.org _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: ARRL Request for Comments on Digital Modes - OPPOSE THIS!
Well, what most don't seem to realize is that this push for wideband data is coming mostly from yachtsmen who want a service in the amateur bands to avoid the cost ot wideband marine data services that they presently have. So this really is an attempt to set up commercial activity in the amateur bands!! WE DON'T NEED OR WANT THIS!! PLEASE CONTACT YOUR ARRL REPRESENTATIVES AND ASK THEM TO OPPOSE THIS BLATANT GRAB FOR OUR SPECTRUM FOR NON-AMATEUR PURPOSES! Best regards, Charlie Cunningham, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Merle Bone Sent: Sunday, March 09, 2014 2:54 PM To: topband@contesting.com Subject: Topband: ARRL Request for Comments on Digital Modes I was interested in the comments on this reflector about the request for “amateur radio operator’s” comments on digital modes. I personally believe the ARRL proposal was a poor attempt to provide some opportunity for high speed data on the Ham Bands. There are a lot of issues associated with the introduction of high speed wide-band data on the ham bands. 1. Amateur radio equipment is not designed to create or transmit 2.8KHz data signals single carrier or multi-carrier . without creating significant “out of band” distortion products. 2. I seriously doubt anyone will be trying to transmit a 2.8KHz data signal on “relatively low power.” That means we will be opening the bands up to “internet type traffic” using full power amateur signals. Few of todays linear amplifiers are designed to “faithfully reproduce” multi carrier data signals (I have spoken with an ARRL leader, who told me they expect to see multicarrier high speed data signals introduced). 3. “Identifying” wideband data signals will be very very difficult. Most of todays wideband data modems operate over 5 or 6 modes – depending on receive signal quality – making it very hard to know what mode the signal is operating with at any given time. Further, imbedded coding – to optimize signal detection can have the effect of “encrypting” the clear data. 4. People don’t “talk” over high speed data circuits – unless they are using digitized voice signals. What people do is “move data” from one machine to another. So what is going to happen is “machine to machine” band usage will begin to replace “people to people” band usage. Machines can send “virtually unlimited” data to other machines. Link holding times can go from minutes to hours. This can be especially desirable in countries without “ubiquitous” internet service. 5. Radio Amateurs have almost no equipment to understand their transmitted signals. Wideband data signals will have to be “monitored” to allow the operator to know that they are actually limiting their bandwidth to 2.8 KHZ and to know that they are using the maximum bandwidth required by their signaling mode. 6. The League has proposed all current “data bandwidth allocation” be opened to wideband data. The ARRL “bandplan” has no standing in the law and is not enforceable – just look at band operations during any major RTTY contest. People will operate wideband data signals wherever it is legal. If the League leadership wants to introduce wideband data to the Amateur Bands, it should be done very carefully, in a limited way, in order to understand the interaction of wideband data modes with current signal modes. This is about the third attempt at this kind of band restructuring. I am really glad that some of the Board members – for the first time I remember in over 10 years – have opened this issue to comment by radio amateurs. I hope everyone will think about this and submit their comments. This could have a very significant effect on how our ham bands operate. _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: New MFJ 259C available
Thanks, Jim! That's good information, I'll look into it! Thanks! Most of my VNA work in recent years was in the design, tuning and matching of embedded antennas for 900 MHz, 1.4 GHz and 2.5 GHz for electricity, gas and water meters home-area networks and personal security devices. I mostly used a little Smith Chart program called WinSmith 2.0 that was sufficient for my tasks. Those programs you have listed sound interesting, indeed! I'll check 'em out! Many thanks! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Jim Brown Sent: Wednesday, March 05, 2014 12:25 AM To: topband@contesting.com Subject: Re: Topband: New MFJ 259C available On 3/4/2014 7:04 PM, Charlie Cunningham wrote: I'd also like to be able to apply VNA measurements to some of my HF antennas and I might be willing to take a laptop out there to do that, but I could also just calibrate out the feedline to move the measurement plane out to the antenna and do the measurments from indoors! Would be nice to have the capability! Charlie, Virtually all of the major vector analyzers can write impedance data files in a standard plain text format (called Touchstone) that can be imported by modeling programs like SimSmith. They also allow you to do TDR of the system, so you can subtract out the feedline. From there you can design matching networks. There's a piece on my website that lists several decent analyzers, then shows you to use SimSmith to do these things. SimSmith is FREE, and runs in Java. Dan, AC6LA, has some wonderful Excel spreadsheets that work with this data. One of them will take open circuit and short circuit sweeps for a piece of transmission line and compute Zo, Vf, and attenuation vs frequency. Most of his spreadsheets are free. Dan also sells a spreadsheet that automates EZNEC and, I think, will do optimization. 73, Jim K9YC _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: New MFJ 259C available
True!! Check out the prices of the Cal kits for the Agilent VNAs! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Jim Brown Sent: Tuesday, March 04, 2014 1:36 PM To: topband@contesting.com Subject: Re: Topband: New MFJ 259C available On 3/4/2014 7:25 AM, Paul Christensen wrote: My only concern with the VNWA is in its ability to measure Topband antenna systems where sweeps are required into the AMBC band. I'm a VERY happy owner of the 3E model VNWA. I've made measurements on my 160M antennas with no difficulty, but I'm out in the boonies, not close enough to strong BC signals to have seen any issues. As to precision of calibration loads -- after I got the VNWA, I did a search looking for calibration loads, and quickly learned that if you want better than 1% precision, it's easy to spend as much for the load as for the VNWA itself! 73, Jim K9YC _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: New MFJ 259C available
Those should surely be accurate enough, but what kind of connectors? Charlie, K4OT V -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carl Sent: Tuesday, March 04, 2014 2:41 PM To: j...@audiosystemsgroup.com; topband@contesting.com Subject: Re: Topband: New MFJ 259C available Can HP microwave loads be used? I have a set good to 24 GHz and another to 50 GHz. Carl KM1H - Original Message - From: Jim Brown j...@audiosystemsgroup.com To: topband@contesting.com Sent: Tuesday, March 04, 2014 1:35 PM Subject: Re: Topband: New MFJ 259C available On 3/4/2014 7:25 AM, Paul Christensen wrote: My only concern with the VNWA is in its ability to measure Topband antenna systems where sweeps are required into the AMBC band. I'm a VERY happy owner of the 3E model VNWA. I've made measurements on my 160M antennas with no difficulty, but I'm out in the boonies, not close enough to strong BC signals to have seen any issues. As to precision of calibration loads -- after I got the VNWA, I did a search looking for calibration loads, and quickly learned that if you want better than 1% precision, it's easy to spend as much for the load as for the VNWA itself! 73, Jim K9YC _ Topband Reflector Archives - http://www.contesting.com/_topband - No virus found in this message. Checked by AVG - www.avg.com Version: 2014.0.4335 / Virus Database: 3705/7150 - Release Date: 03/04/14 _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: New MFJ 259C available
Well, SMA is probably the most generally useful. With the adaptors in place, we just have to make sure that we include the adaptors in our calibrations. When it gets to be really witchy is when we need to calibrate a miniature coax or semi-rigid line to solder into a PC board to measure at the input of an IC, or balun, or printed antenna etc. Then we have to trim the line very carefully and tack tiny surface mount 50 ohm and 0-ohm resistors across the line to calibrate - each step being done under a microscope! Tedious - but it can be done! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carl Sent: Tuesday, March 04, 2014 3:01 PM To: Charlie Cunningham; j...@audiosystemsgroup.com; topband@contesting.com Subject: Re: Topband: New MFJ 259C available SMA for the 24GHz, open, thru and short. I also have high end adaptors to N, APC, etc. There may even be an old type N cal kit from back in the eighties Carl KM1H - Original Message - From: Charlie Cunningham charlie-cunning...@nc.rr.com To: 'Carl' k...@jeremy.mv.com; j...@audiosystemsgroup.com; topband@contesting.com Sent: Tuesday, March 04, 2014 2:53 PM Subject: RE: Topband: New MFJ 259C available Those should surely be accurate enough, but what kind of connectors? Charlie, K4OT V -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carl Sent: Tuesday, March 04, 2014 2:41 PM To: j...@audiosystemsgroup.com; topband@contesting.com Subject: Re: Topband: New MFJ 259C available Can HP microwave loads be used? I have a set good to 24 GHz and another to 50 GHz. Carl KM1H - Original Message - From: Jim Brown j...@audiosystemsgroup.com To: topband@contesting.com Sent: Tuesday, March 04, 2014 1:35 PM Subject: Re: Topband: New MFJ 259C available On 3/4/2014 7:25 AM, Paul Christensen wrote: My only concern with the VNWA is in its ability to measure Topband antenna systems where sweeps are required into the AMBC band. I'm a VERY happy owner of the 3E model VNWA. I've made measurements on my 160M antennas with no difficulty, but I'm out in the boonies, not close enough to strong BC signals to have seen any issues. As to precision of calibration loads -- after I got the VNWA, I did a search looking for calibration loads, and quickly learned that if you want better than 1% precision, it's easy to spend as much for the load as for the VNWA itself! 73, Jim K9YC _ Topband Reflector Archives - http://www.contesting.com/_topband - No virus found in this message. Checked by AVG - www.avg.com Version: 2014.0.4335 / Virus Database: 3705/7150 - Release Date: 03/04/14 _ Topband Reflector Archives - http://www.contesting.com/_topband - No virus found in this message. Checked by AVG - www.avg.com Version: 2014.0.4335 / Virus Database: 3705/7150 - Release Date: 03/04/14 _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: ARRL Board Requests Member Comments About Digital Modes
What the hell is the need for wideband data in the amateur radio bands? Is it just a ploy to usurp the amateur bands for commercial purposes? And there's a heck of a lot more band width available at VHF and UHF! Why wideband at HF?? Makes no sense to me! ?? Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Joe Subich, W4TV Sent: Tuesday, March 04, 2014 3:38 PM To: topband@contesting.com Subject: Re: Topband: ARRL Board Requests Member Comments About Digital Modes I'm sure there are some military/commercial systems that will do it but I don't believe that even the Flex are clean enough to handle the really wide band commercial data modulations. 73, ... Joe, W4TV On 3/4/2014 11:30 AM, Mike Waters wrote: FWIW, I believe such transceivers do exist. Don't the Flex SDRs have that capability? ... as if there are any amateur transceivers capable of operating with data bandwidth greater than 2.8 KHz. _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: New MFJ 259C available
No, Price! Way above Topband in frequency, but the principles of Vector Network Analysis and calibrating out the cables to move the measurement plane to the end of the cable are the same at 1.8 MHz as they are at 2.5 GHz. And the Smith Chart applies at all frequencies from near DC to daylight! J 73, Charlie, K4OTV From: HAROLD SMITH JR [mailto:w0ri...@sbcglobal.net] Sent: Tuesday, March 04, 2014 6:32 PM To: Charlie Cunningham; 'Carl'; j...@audiosystemsgroup.com; topband@contesting.com Subject: Re: Topband: New MFJ 259C available This sure doesn't sound like topband to me ! Price W0RI Well, SMA is probably the most generally useful. With the adaptors in place, we just have to make sure that we include the adaptors in our calibrations. When it gets to be really witchy is when we need to calibrate a miniature coax or semi-rigid line to solder into a PC board to measure at the input of an IC, or balun, or printed antenna etc. Then we have to trim the line very carefully and tack tiny surface mount 50 ohm and 0-ohm resistors across the line to calibrate - each step being done under a microscope! Tedious - but it can be done! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carl Sent: Tuesday, March 04, 2014 3:01 PM To: Charlie Cunningham; j...@audiosystemsgroup.com; topband@contesting.com Subject: Re: Topband: New MFJ 259C available SMA for the 24GHz, open, thru and short. I also have high end adaptors to N, APC, etc. There may even be an old type N cal kit from back in the eighties Carl KM1H - Original Message - From: Charlie Cunningham charlie-cunning...@nc.rr.com To: 'Carl' k...@jeremy.mv.com; j...@audiosystemsgroup.com; topband@contesting.com Sent: Tuesday, March 04, 2014 2:53 PM Subject: RE: Topband: New MFJ 259C available Those should surely be accurate enough, but what kind of connectors? Charlie, K4OT V -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carl Sent: Tuesday, March 04, 2014 2:41 PM To: j...@audiosystemsgroup.com; topband@contesting.com Subject: Re: Topband: New MFJ 259C available Can HP microwave loads be used? I have a set good to 24 GHz and another to 50 GHz. Carl KM1H - Original Message - From: Jim Brown j...@audiosystemsgroup.com To: topband@contesting.com Sent: Tuesday, March 04, 2014 1:35 PM Subject: Re: Topband: New MFJ 259C available On 3/4/2014 7:25 AM, Paul Christensen wrote: My only concern with the VNWA is in its ability to measure Topband antenna systems where sweeps are required into the AMBC band. I'm a VERY happy owner of the 3E model VNWA. I've made measurements on my 160M antennas with no difficulty, but I'm out in the boonies, not close enough to strong BC signals to have seen any issues. As to precision of calibration loads -- after I got the VNWA, I did a search looking for calibration loads, and quickly learned that if you want better than 1% precision, it's easy to spend as much for the load as for the VNWA itself! 73, Jim K9YC _ Topband Reflector Archives - http://www.contesting.com/_topband - No virus found in this message. Checked by AVG - www.avg.com http://www.avg.com/ Version: 2014.0.4335 / Virus Database: 3705/7150 - Release Date: 03/04/14 _ Topband Reflector Archives - http://www.contesting.com/_topband - No virus found in this message. Checked by AVG - www.avg.com Version: 2014.0.4335 / Virus Database: 3705/7150 - Release Date: 03/04/14 _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: New MFJ 259C available
Well, I might be willing to use a VNA that attaches to a computer in my Lab, if I could get away with much lower cost than one of the Agilent or Rhode and Schwarz VNAs. I'd like to have the capability to cover the 2.5 GHz band and go considerably higher so I could look at harmonic filters for 2.5GHz. I'd also like to be able to apply VNA measurements to some of my HF antennas and I might be willing to take a laptop out there to do that, but I could also just calibrate out the feedline to move the measurement plane out to the antenna and do the measurments from indoors! Would be nice to have the capability! I have seen a commercial VNA with a lot of capability that attaches to a Computer for considerably less than a good Agilent VNA! I'm thinking about it when some of my invoices get paid! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Tom W8JI Sent: Tuesday, March 04, 2014 9:48 PM To: topband Subject: Re: Topband: New MFJ 259C available I thought a much more useful item would have been a 259 revision that was totally immune to RFI, and still did about the same stuff over a wider frequency range. As I looked at things over the years, very few people want VNA's that attach to PC's, and that market is covered anyway. I thought a 259 revision wth direct conversion receivers and a wide frequency range, and a calibrate function, and just basically do what the 259B does now, would have been much better. That would have solved all the major issues, and not cost a fortune or required a computer. My 259B does 99% of what I need, but would be a whole lot better with a cal correction (open, short, load), sweep, wide range, and receivers with a phase detector instead of a diode bridge. 73 Tom _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: AM broadcast tower and 160m dxpedition
No, I don't believe 240' is too high - especially if the tower has a base insulator! It would be so close to 1/2 wave on 160, that it could be fed very well as a 1/2 wave radiator on 160, either via a parallel tuned tank or a 1/4 wave of perhaps 450 oh ladder line. A 1/2 wave radiator wis an excellent transmit antenna, and, because of the high feed-point impedance can be driven against a very modest ground arrangement Like you, though, I believe they would do well to put up some terminated loops, or perhaps a Beverage (or 3?) for receive antennas! A 240' vertical would, I think, be a VERY noisy receive antenna. If they put up a KAZ terminated loop that only requires one overhead support, they could steer it around with ropes and weights on the ground. The KAZ is like ON4UN's FO0AAA 160 receive loop. 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Richard Karlquist Sent: Tuesday, February 25, 2014 3:38 PM To: topband@contesting.com Subject: Re: Topband: AM broadcast tower and 160m dxpedition Congratulations on your adventure. In the past, I have seen some of these AM tower efforts ruined by lousy receive conditions. I suggest you get an advance team out to the site to check out the noise level etc. and maybe put up some temporary beverages, loops, whatever and LISTEN on them. Use WWV and WWVH on 2.5 MHz as a beacon. Others can comment on whether 240 feet is too high. Rick N6RK _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: AM broadcast tower and 160m dxpedition
Good point! -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Ashton Lee Sent: Tuesday, February 25, 2014 4:03 PM To: DALE LONG Cc: topband@contesting.com Subject: Re: Topband: AM broadcast tower and 160m dxpedition I would be especially mindful of corrosion issues in tower planning in the Caribbean. There was a recent article in the Contest Journal on the ever difficult tower corrosion experienced at PJ2T. On Feb 25, 2014, at 1:17 PM, DALE LONG dale.l...@prodigy.net wrote: Gentlemen: I have been reluctant to ask for help which did not relate directly to our reflector. But today I got up my courage, so here goes. I have been invited to lead a group of amateurs to help build an AM tower in Haiti. Two things that may relate to some of our readers: 1. I will be returning to Haiti in November to build a 240foot AM broadcast tower. I know there are many AM broadcast engineers on this list and would like to have your advice. Specifically we are searching for a large conical base insulator. Sometimes when a tower rusts, they are disgarded or thrown on a pile somewhere. We would like to buy one, and possibly a tower as well. 2. In December of this year, I am organizing a small group to go to Haiti and participate in the 160m contest. (this of course is dependent on the tower being built.) I am particularly pleased that amateurs have been invited to help. Sometimes broadcast engineers do not have the highest opinions of amateur installations. So we do want to do it right. We have a 9-acre parcel of land along the ocean and part of the area is a salt-water marsh. I think there hasnt been any serious 160m activity from Haiti for a number of years. This location would present a nice opportunity for a serious lowband operation. If you have any information about base insulators/towers, or if you would like to join a 160m dxpedition to Haiti, please respond off the reflector to n3b...@gmail.com Thanks for your time. Dale - N3BNA _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: AM broadcast tower and 160m dxpedition
Well, he's talking about going in November - maybe in time for CQWW CW -but probably not. -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Joe Subich, W4TV Sent: Tuesday, February 25, 2014 4:10 PM To: topband@contesting.com Subject: Re: Topband: AM broadcast tower and 160m dxpedition Others can comment on whether 240 feet is too high. 240 feet tuned/matched with a parallel tuned tapped tank should work quite well based on the information in K3LC's article in QEX Nov/Dec 2013. Of course, 240 feet would also make an excellent support for a wire 4 square or parasitic array aimed back across the center of the US (for ARRL 160). 73, ... Joe, W4TV On 2/25/2014 3:38 PM, Richard Karlquist wrote: Congratulations on your adventure. In the past, I have seen some of these AM tower efforts ruined by lousy receive conditions. I suggest you get an advance team out to the site to check out the noise level etc. and maybe put up some temporary beverages, loops, whatever and LISTEN on them. Use WWV and WWVH on 2.5 MHz as a beacon. Others can comment on whether 240 feet is too high. Rick N6RK _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: AM broadcast tower and 160m dxpedition
That's not so surprising Gary !! te Way the Beverages and similar slow-wave antennas work is that they depend on the lossy GND underneath for their operation, so a salt marsh would not be a very beneficial GND structure under a Beverage! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Gary Smith Sent: Tuesday, February 25, 2014 5:09 PM To: Topband@contesting.com Subject: Re: Topband: AM broadcast tower and 160m dxpedition My Inv-L is on a salt marsh on Long Island Sound in Connecticut I ran two bidirectional 860' beverages over the salt marsh. I had terrible results with the beverages, very noisy and hardly any improvement over the Inv-L, much of the time the Inv-L was more effective on Rx. With that, my experience of beverages salt marshes says to avoid this route. I ended up with a HI-Z Triangular array for Rx and it works very well at the same location. Gary KA1J No, I don't believe 240' is too high - especially if the tower has a base insulator! It would be so close to 1/2 wave on 160, that it could be fed very well as a 1/2 wave radiator on 160, either via a parallel tuned tank or a 1/4 wave of perhaps 450 oh ladder line. A 1/2 wave radiator wis an excellent transmit antenna, and, because of the high feed-point impedance can be driven against a very modest ground arrangement Like you, though, I believe they would do well to put up some terminated loops, or perhaps a Beverage (or 3?) for receive antennas! A 240' vertical would, I think, be a VERY noisy receive antenna. If they put up a KAZ terminated loop that only requires one overhead support, they could steer it around with ropes and weights on the ground. The KAZ is like ON4UN's FO0AAA 160 receive loop. 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Richard Karlquist Sent: Tuesday, February 25, 2014 3:38 PM To: topband@contesting.com Subject: Re: Topband: AM broadcast tower and 160m dxpedition Congratulations on your adventure. In the past, I have seen some of these AM tower efforts ruined by lousy receive conditions. I suggest you get an advance team out to the site to check out the noise level etc. and maybe put up some temporary beverages, loops, whatever and LISTEN on them. Use WWV and WWVH on 2.5 MHz as a beacon. Others can comment on whether 240 feet is too high. Rick N6RK _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Fw: AM broadcast tower and 160m dxpedition
Perhaps so - but Dale is gong down there to put in a 240' broadcast tower. 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Bruce Sent: Wednesday, February 26, 2014 6:19 AM To: topband@contesting.com Subject: Topband: Fw: AM broadcast tower and 160m dxpedition I agree with Herb. Also Haiti is on an earthquake fault. The quarter wave tower would have a better chance of survival and is safer. 73 Bruce-K1FZ - Original Message - From: Herb Schoenbohm he...@vitelcom.net To: topband@contesting.com Sent: Tuesday, February 25, 2014 5:53 PM Subject: Re: Topband: AM broadcast tower and 160m dxpedition Half wave verticals have been very disappointing to me over the years when I had the tall BC towers in my backyard to play with after midnight on 160. I have had much better result in hanging 1/2 wave center fed slopers of of high towers. Radio stations seem to prefer if they have extermely high towers like KSTP in St. Paul to split them with an insulated section and feed them as a Franklin design and pick up some additional gain along the ground. Some designs do not required two stacked half waves but achieve significant height by folding back the top and bottom sections with a cage or in fact using a top hat and an equivalent on the bottom. The proper phasing section is mounted in a box at the center split and the feedline is inside the tower. Why this should work any better than a straight 1/2 wave, as it seems to is available perhaps in those who can model and compare the two. It seems however that topbanders who expect good results with a bottom fed 1/2 over a traditional 1/4 wave over a good ground, seem to come away disappointed like myself. Herb Schoenbohm, KV4FZ _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Shunt feeding the Skyneedle - new developments
Good morning, JC Well, in its present configuration, Carl's antenna is not really a folded monopole, although it did start our as one when he had his gamma match connected at full height of 90'. At present he has his gamma attached at 67' - about 2/3 of the way up the tower. But that's sort of a nit-pick - otherwise, I do agree that the gamma match (with its 3-wire cage, is a shorted transmission line section. Since it's less than 1/4 wavelength it will have inductive reactance that needs to be canceled with the series tuning capacitor. Carl should have a good topband transmit antenna! As he builds out his radial field, the efficiency will hopefully improve some more. I hope he had fun with it last night, but 160 conditions of late have been rather poor - apparently because of the sun's coronal mass ejection a few days ago. Have a good day!\ 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of JC N4IS Sent: Sunday, February 23, 2014 7:20 AM To: 'Richard (Rick) Karlquist'; 'Carl Braun'; 'Carl'; '160' Cc: w...@att.net; ad...@arrl.net Subject: Re: Topband: Shunt feeding the Skyneedle - new developments I'm sure it will play well in terms of keeping your transmitter happy but the relatively large bandwidth you are measuring is indicative of substantial loss in the system somewhere. This would be a large bandwidth even if you did not have the bandwidth narrowing effects of a shunt feed. Hi guys, the 3 wires is actually a transmission line and the antenna is well known as Folded Unipole with 200 ohms impedance. My antenna is a Folded Unipole as well and has the same broadband SWR measurement's. The loss is the same for any tuning circuit it has nothing to do with the bandwidth. The ground plane does, and in this case it is the same, right? 73's JC N4IS _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: from Mac Reynolds, w9evi - Rellector post repeats
Thanks, Carl Well, I received this e-mail from you 2X - because you addressed it to me and also to topband. I often do the same if I want to communicate something to you, that I think might be worth sharing with others on the reflector. Have you ever seen any of my posts more than 2X? Thanks and have a good day! 73, Charlie, K4OTV -Original Message- From: ZR [mailto:z...@jeremy.mv.com] Sent: Sunday, February 23, 2014 11:15 AM To: Charlie Cunningham; 'HAROLD SMITH JR'; w9...@aol.com; topband@contesting.com Subject: Re: Topband: from Mac Reynolds, w9evi - Rellector post repeats Ive been receiving duplicates for quite awhile Charlie, OK now. Carl KM1H - Original Message - From: Charlie Cunningham charlie-cunning...@nc.rr.com To: 'HAROLD SMITH JR' w0ri...@sbcglobal.net; w9...@aol.com; topband@contesting.com Sent: Sunday, February 23, 2014 10:03 AM Subject: Re: Topband: from Mac Reynolds, w9evi - Rellector post repeats Thanks, Harold! Well, I would have thought I'd see repeats here also. I think that what might have thrown Mac, was that there I have had a lengthy exchange, over several days, with Carl Braun, AG6X (and also W8JI, and KM1H) over the past few days regarding Carl's experiments and modifications of his 90' shunt-fed Skyneedle antenna. We often ping-ponged exchanges back and forth without changing the subject line in the e-mails, so if Mac didn't actually read them, they might have appeared to be repeats, And they have been NUMEROUS! Anyway, Carl has arrived at what appears to be a really good solution to his antenna design and I expect to see good results! Thanks for your update and input, Harold! Have a good day! 73, Charlie, K4OTV From: HAROLD SMITH JR [mailto:w0ri...@sbcglobal.net] Sent: Sunday, February 23, 2014 10:35 AM To: Charlie Cunningham; w9...@aol.com; topband@contesting.com Subject: Re: Topband: from Mac Reynolds, w9evi - Rellector post repeats Charlie, I have NEVER seen a repeat of your postings. 73 de Price W0RI near St Louis, MO Good morning, Mac Please let me know if you see further repeats of any of my posts to the reflector. No one else had told me about that, so I appreciate your letting me know. After your e-mail, I did restart my computer and did a malware scan. The malware scan did find one item that needed to be removed. I did remove that item and restarted the computer. Perhaps I need to do some further spyware scans and do a full in-depth virus scan. Haven't done that in a week or so. I don't see repeats of my own posts to the reflector, so I don't know what to think Please let me know if you see further repeats of my posts to the reflector. I'm sending this post to topband also as a test for repeats. Thanks and have a good day! 73, Charlie, K4OTV From: w9...@aol.com [mailto:w9...@aol.com] Sent: Saturday, February 22, 2014 12:29 PM To: charlie-cunning...@nc.rr.com Subject: from Mac Reynolds, w9evi Dear OM Cunningham - Something has gone wrong: Every time you send a message to Topband, I get a long list of repeats of your message. The last one, about some antenna thing, was repeated to me fifteen times! That about fills my inbox. The cause must be local to you because no other e=mail to Topband does that. Hope you cure ure it..73 de Mac. _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband - No virus found in this message. Checked by AVG - www.avg.com Version: 2014.0.4335 / Virus Database: 3705/7117 - Release Date: 02/22/14 _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: from Mac Reynolds, w9evi - Rellector post repeats
Yikes! Let me see how I addressed those last couple e-mails, Carl! Then I may need to do some more malware, spyware, and ati-virus scans! Thanks for the info! I'll continue to look into it. Sounds like some more scans and digging may be in order! Thanks and have a good da! Charlie -Original Message- From: Carl [mailto:k...@jeremy.mv.com] Sent: Sunday, February 23, 2014 12:56 PM To: Charlie Cunningham; 'HAROLD SMITH JR'; w9...@aol.com; topband@contesting.com Subject: Re: Topband: from Mac Reynolds, w9evi - Rellector post repeats Im not talking about 2X and now youre back to 3X again. - Original Message - From: Charlie Cunningham charlie-cunning...@nc.rr.com To: 'ZR' z...@jeremy.mv.com; 'HAROLD SMITH JR' w0ri...@sbcglobal.net; w9...@aol.com; topband@contesting.com Sent: Sunday, February 23, 2014 10:41 AM Subject: Re: Topband: from Mac Reynolds, w9evi - Rellector post repeats Thanks, Carl Well, I received this e-mail from you 2X - because you addressed it to me and also to topband. I often do the same if I want to communicate something to you, that I think might be worth sharing with others on the reflector. Have you ever seen any of my posts more than 2X? Thanks and have a good day! 73, Charlie, K4OTV -Original Message- From: ZR [mailto:z...@jeremy.mv.com] Sent: Sunday, February 23, 2014 11:15 AM To: Charlie Cunningham; 'HAROLD SMITH JR'; w9...@aol.com; topband@contesting.com Subject: Re: Topband: from Mac Reynolds, w9evi - Rellector post repeats Ive been receiving duplicates for quite awhile Charlie, OK now. Carl KM1H - Original Message - From: Charlie Cunningham charlie-cunning...@nc.rr.com To: 'HAROLD SMITH JR' w0ri...@sbcglobal.net; w9...@aol.com; topband@contesting.com Sent: Sunday, February 23, 2014 10:03 AM Subject: Re: Topband: from Mac Reynolds, w9evi - Rellector post repeats Thanks, Harold! Well, I would have thought I'd see repeats here also. I think that what might have thrown Mac, was that there I have had a lengthy exchange, over several days, with Carl Braun, AG6X (and also W8JI, and KM1H) over the past few days regarding Carl's experiments and modifications of his 90' shunt-fed Skyneedle antenna. We often ping-ponged exchanges back and forth without changing the subject line in the e-mails, so if Mac didn't actually read them, they might have appeared to be repeats, And they have been NUMEROUS! Anyway, Carl has arrived at what appears to be a really good solution to his antenna design and I expect to see good results! Thanks for your update and input, Harold! Have a good day! 73, Charlie, K4OTV From: HAROLD SMITH JR [mailto:w0ri...@sbcglobal.net] Sent: Sunday, February 23, 2014 10:35 AM To: Charlie Cunningham; w9...@aol.com; topband@contesting.com Subject: Re: Topband: from Mac Reynolds, w9evi - Rellector post repeats Charlie, I have NEVER seen a repeat of your postings. 73 de Price W0RI near St Louis, MO Good morning, Mac Please let me know if you see further repeats of any of my posts to the reflector. No one else had told me about that, so I appreciate your letting me know. After your e-mail, I did restart my computer and did a malware scan. The malware scan did find one item that needed to be removed. I did remove that item and restarted the computer. Perhaps I need to do some further spyware scans and do a full in-depth virus scan. Haven't done that in a week or so. I don't see repeats of my own posts to the reflector, so I don't know what to think Please let me know if you see further repeats of my posts to the reflector. I'm sending this post to topband also as a test for repeats. Thanks and have a good day! 73, Charlie, K4OTV From: w9...@aol.com [mailto:w9...@aol.com] Sent: Saturday, February 22, 2014 12:29 PM To: charlie-cunning...@nc.rr.com Subject: from Mac Reynolds, w9evi Dear OM Cunningham - Something has gone wrong: Every time you send a message to Topband, I get a long list of repeats of your message. The last one, about some antenna thing, was repeated to me fifteen times! That about fills my inbox. The cause must be local to you because no other e=mail to Topband does that. Hope you cure ure it..73 de Mac. _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband - No virus found in this message. Checked by AVG - www.avg.com Version: 2014.0.4335 / Virus Database: 3705/7117 - Release Date: 02/22/14 _ Topband Reflector Archives - http://www.contesting.com/_topband - No virus found in this message. Checked by AVG - www.avg.com Version: 2014.0.4335 / Virus Database: 3705/7117 - Release Date: 02/22/14 _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Shunt feeding the Skyneedle - new developments
Hi, Carl Well, paying with your load on a Smith Chart, tuning out the -j11 only improved the VSWR from 1.3:1 to 1.1 - not really worth doing! Also, you would need a fairly large inductor to obtain 1 uHy of inductance with low loss, and I expect that you would incur more loss in the inductor (that would subtract directly from your transmitted power) than you would gain in improved mismatch loss by improving the VSWR from 1.3 t 1.1!! Keep in mind also that the inductor would also have stray capacitance to the enclosure walls that will lower its Q ! I wouldn't do it! 1.3:1 is great!! Enjoy!! You will help your overall performance much more by building a terminated receiving loop - a KAZ, flag or pennant configuration to help your HEARING!! MY KAZ loop did wonders for me!! GL and have fun! 73, Charlie, K4OTV -Original Message- From: Carl Braun [mailto:carl.br...@lairdtech.com] Sent: Saturday, February 22, 2014 7:23 AM To: Charlie Cunningham; 'ZR'; '160' Subject: RE: Topband: Shunt feeding the Skyneedle - new developments Charlie Thanks for the tip. I may play with a bit of inductance just to see how the system reacts. Not sure if I can post a pic here but I'm including a shot of the panel and the cap...hope you all can see it. The static bleed choke has been removed and I'm awaiting PL 259 connectors from my friends at RF parts. My crazy dog gets pretty loopy when we play with the Frisbee so I'm considering a trial cut in the asphalt to see how easy or ugly the process is. I hear the secret is all in the blade that's used. You Tube has some videos showing the procedure for cutting asphalt...we'll see. Thanks again Carl AG6X -Original Message- From: Charlie Cunningham [mailto:charlie-cunning...@nc.rr.com] Sent: Friday, February 21, 2014 8:18 PM To: Carl Braun; 'ZR'; '160' Subject: RE: Topband: Shunt feeding the Skyneedle - new developments Hi, Carl Well, I think that what you are doing with your radials should be OK. I guess I'd rather get them under the asphalt if I could where they wouldn't get torn up or b a trip hazard. BTW I I was playing with your match on the Smith Chart and if you'll add about 1 uHy inductance in series with the connector (SO-239?) where you feedline leaves the enclosure, that will take you to 45 +j0, but I'd be concerned about incurring more losses in the inductor than any tiny mismatch loss from the -j11 term. I probably wouldn't do it. 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carl Braun Sent: Friday, February 21, 2014 10:56 PM To: Charlie Cunningham; 'ZR'; '160' Subject: Re: Topband: Shunt feeding the Skyneedle - new developments I'm working on the radial field weekly. Here is a theoretical question that results from my particular QTH. The Skyneedle is situated near a secondary blacktop driveway that is in the back of my property. I have to run radials over the blacktop to the rest of the property and, in order to keep things kind of neat, I'm using multi-conductor rotor cable as radials that travel over the blacktop. I have both 6 conductor and 3 conductor control cable that I'm using. I strip back the jacket at the radial ring...fan out the wires 3 apart and attach them to the 1 1/2 copper pipe I'm using as a radial ring around the base of the 'Needle'. Then the radial wires converge back into the cable jacket then travel across the 10' blacktop driveway and then they are removed from the cable jacket where they fan out into the dirt and are buried. Most of these radial wires are 60' to 100' once they leave the jacket. Any problem with what I'm doing here? I understand that it would be better if they fanned out directly from the base but I can have 50+ wires traveling over the blacktop. I was even considering getting an asphalt blade and cutting some channels into the blacktop...burying the jacketed cable into the asphalt and then sealing then in so I'm not running over them or tripping over them when playing Frisbee with the hound. My Guatemalan yard worker has been burying radial wires for the last month and thinks that I'm LOCO but he likes getting paid at the end of the day. As we speak I have a total of 34 radials with the shortest being 30' with the longest at 100'. Most of them are 60-70'. Four of them are tied into my 40m phased array radial field comprised of 90-100 radials under each antenna ranging from 40' to 80'. I can change the height of these verticals from 33' for 40m to 66' for 80m. 1/2 wl spacing on 40 and 1/4 wl spacing on 80. Carl AG6X -Original Message- From: Charlie Cunningham [mailto:charlie-cunning...@nc.rr.com] Sent: Friday, February 21, 2014 7:36 PM To: 'ZR'; Carl Braun; '160' Subject: RE: Topband: Shunt feeding the Skyneedle - new developments Well, if I recall correctly, Carl, Carl said his feedline was about 70' of LMR-400, so even at 2 2:1 or 2.5:1 VSWR, the excess losses in 70' of LMR-400 at 1.8 MHz
Re: Topband: Shunt feeding the Skyneedle - new developments
I completely agree with Tom. Carl! I'd leave it alone(for the reasons that I stated previously)! I expect that you would lose more than you would gain by adding an inductor!! If it ain't broke don't fix it!! You might want to put some effort into a good terminated receiving loop! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Tom W8JI Sent: Saturday, February 22, 2014 9:09 AM To: Carl Braun; '160' Subject: Re: Topband: Shunt feeding the Skyneedle - new developments Thanks for the tip. I may play with a bit of inductance just to see how the system reacts. This is way more problematic than it needs to be. First, no one even knows if the reactance is real or a false reading caused by a bit error from calibration or noise. Second, no one knows the sign of the reactance if it is there. It might be already be inductive. Third, if the capacitor is not maxed out or at minimum and still has range left, which yours does, the capacitor will adjust out any reactance without adding anything else. There are certain bridge voltages that with even one or two bits error, which is 2/256 bits or less than 1% error in voltages, where 10 ohms might be calculated. The algoryth tries to take that error out by watching SWR near bridge balance instead of bridge arm voltages, but I have no idea how the unit is calibrated or if the antenna system has noise causing a bit error. All of this is pretty much meaningless. Even if it is a 1.3 :1 SWR, it is not going to be a problem. Also, if the real part is near 40 ohms and you have a high Q antenna system and losses, you might find lowest SWR is not X=0 because of interactions between resistance and reactance as things are tuned. I would not even guess at a cure for something with a bunch of unknowns that might not even be a problem. I think this is a bigger worry and more complex than it should be. 73 Tom _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Shunt feeding the Skyneedle - new developments
I don't expect that ANY of those are valid concerns at 1.3:1 VSWR!! -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carl Sent: Saturday, February 22, 2014 9:14 AM To: Charlie Cunningham; 'Carl Braun'; '160' Subject: Re: Topband: Shunt feeding the Skyneedle - new developments Im not concerned by what is measured at the matching unit or a miniscule cable loss; just what is transformed back to the amp and its ability to load at full power without arcing, running out of or having too much fixed padder C during QSY's. Contests do not stay just in the narrow CW 50 KHz window and not having to use an external tuner is a big plus. Ive always modified my amps to work with my antennas on 160 and 80/75. Carl KM1H - Original Message - From: Charlie Cunningham charlie-cunning...@nc.rr.com To: 'ZR' z...@jeremy.mv.com; 'Carl Braun' carl.br...@lairdtech.com; '160' topband@contesting.com Sent: Friday, February 21, 2014 10:35 PM Subject: Re: Topband: Shunt feeding the Skyneedle - new developments Well, if I recall correctly, Carl, Carl said his feedline was about 70' of LMR-400, so even at 2 2:1 or 2.5:1 VSWR, the excess losses in 70' of LMR-400 at 1.8 MHz are almost 0, so if he can match it OK at the transmitter end of the line- no real point in making heroic efforts to achieve a perfect match! He'd gain more by working on his radial field, and he really should do that before doing any more tuning because improving the radials WILL affect the antenna impedance. 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of ZR Sent: Friday, February 21, 2014 10:11 PM To: Charlie Cunningham; 'Carl Braun'; '160' Subject: Re: Topband: Shunt feeding the Skyneedle - new developments The only benefit of getting it better would be a bit more 2:1 VSWR bandwidth to keep the amp happy but even then there is sometimes a gotcha when tuning an antenna. Carl KM1H Subject: Re: Topband: Shunt feeding the Skyneedle - new developments Well, you can do all that, Carl But if your series variable capacitor is not maxed out (fully meshed) if you can increase the capacitance enough to get to j0, you would be at 45 +j0 and on a 1.1:1 VSWR circle. No point int trying to do better than that!! Otherwise, just increase the series capacitance to bring that -j11 as close to j0 as possible and take that! You'd be so near perfect that there would be no real point in going further! Your time and efforts might be better spent working on your radial field! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carl Braun Sent: Friday, February 21, 2014 8:46 PM To: Charlie Cunningham; 'Tom W8JI'; '160' Subject: Re: Topband: Shunt feeding the Skyneedle - new developments Thanks to all who replied Tom W8JI, your comments on the metallic panel and the static bleed choke make sense. I was so pleased with the FLAT SWR reading with the variable cap outside the panel but I guess I can live with the slight SWR. (Thanks Charlie K4OTV). I have a Nye Viking monster tuner but I hate to use it as my Henry amp seems to load strangely when I have it inline so I think I'll just live without it. Can I add some coax (coiled) to bring the X down on the -j11 reading? I did this with the old Telrex and brought the X right down and out of the pic. I'm sure Ill need much more than I would on 14MHz but I think I'd like to try anyway. I'm still going to drop the tower down and add two more gamma wires to create a cage and I still have the option of pulling the gamma wire(s) away from the tower another 8-10 inches to add a few more ohms to the equation. I'm having fun with the experiment. Right now I'm hearing the beginnings of the SSB contest with N7GP, WD5COV, W6YI with the big signals so far. XE is the only DX I've heard. Lots of stateside calling stateside Carl AG6X -Original Message- From: Charlie Cunningham [mailto:charlie-cunning...@nc.rr.com] Sent: Friday, February 21, 2014 5:21 PM To: 'Tom W8JI'; Carl Braun; '160' Subject: RE: Topband: Shunt feeding the Skyneedle - new developments Well, Carl I plotted your 45-j11 load on a Smith Chart (normalized to 50 ohms) and it's very near the origin on a 1.3:1 VSWR circle. Since you have a relatively short feedline of LMR-400, You should be able to just tune it out at the transmitter end of the line, and the LMR-400 line will be operating at such a very low SWR (around 1.3:1 that the excess loss from a 1.3:1 VSWR at 160 is completely trivial and negligible! It may not be completely intellectually satisfying to have -j11 of reactance at the load, but it should match easily and the antenna should work very well! Enjoy! Sounds like that Array solutions static bleed is not as high in impedance as we might wish! A large resistance might give you more satisfactory results! GL! Enjoy! 73, Charlie, K4OTV
Re: Topband: Control cable black conductors
And people DRINK this stuff!!?? :) -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Larry Sent: Saturday, February 22, 2014 9:17 AM To: topband@contesting.com Subject: Re: Topband: Control cable black conductors Phosphoric acid is still listed. 73, Larry W6NWS -Original Message- From: Kenneth Grimm Sent: Saturday, February 22, 2014 7:51 AM To: Tom W8JI Cc: Dave G4GED ; topband Subject: Re: Topband: Control cable black conductors Is it phosphoric acid that gives Coca Cola its peculiar cleaning ability? I no longer can imbibe cola drinks due to a very annoying allergy, so I can't check a label to see if it is listed. I do know that Coke will clean oil deposited on your windshield when commercial windshield washing liquids just cause it to smear...so it has something in it that that may work quite well, and without turning your hands red! 73, Ken - K4XL On Sat, Feb 22, 2014 at 7:38 AM, Tom W8JI w...@w8ji.com wrote: All the other 4 conductors are bright clean copper when stripped. Could anyone tell me why some insulated copper conductors turn black in this way and whether there's a better way of cleaning it off. Water inside the insulation plus sulfur and/or irons that formed copper sulfide or covellite. I've been successful using phosphoric acid. It is sold as a clear liquid wire or mag wheel cleaner around here. You'll know it by how red and painful it turns your hands. _ Topband Reflector Archives - http://www.contesting.com/_topband -- Ken - K4XL BoatAnchor Manual Archive BAMA - http://bama.edebris.com Show me a politician who is poor, and I'll show you a poor politician. - Carlos Hank González _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Shunt feeding the Skyneedle - new developments
Well, Carl the looses in 70' or even 200' of LMR-400 are so low at 1.8 MHz, even at 2.0:1 or 3.0 :1, if he can match it at the transmitter end of the line, it really doesn't matter! Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carl Sent: Saturday, February 22, 2014 9:46 AM To: Charlie Cunningham; 'Carl Braun'; '160' Subject: Re: Topband: Shunt feeding the Skyneedle - new developments That 1.3 is only at ONE frequency Charlie, he is not crystal controlled. What is the 2:1 bandwidth at the amp? Carl KM1H - Original Message - From: Charlie Cunningham charlie-cunning...@nc.rr.com To: 'Carl' k...@jeremy.mv.com; 'Carl Braun' carl.br...@lairdtech.com; '160' topband@contesting.com Sent: Saturday, February 22, 2014 9:23 AM Subject: RE: Topband: Shunt feeding the Skyneedle - new developments I don't expect that ANY of those are valid concerns at 1.3:1 VSWR!! -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carl Sent: Saturday, February 22, 2014 9:14 AM To: Charlie Cunningham; 'Carl Braun'; '160' Subject: Re: Topband: Shunt feeding the Skyneedle - new developments Im not concerned by what is measured at the matching unit or a miniscule cable loss; just what is transformed back to the amp and its ability to load at full power without arcing, running out of or having too much fixed padder C during QSY's. Contests do not stay just in the narrow CW 50 KHz window and not having to use an external tuner is a big plus. Ive always modified my amps to work with my antennas on 160 and 80/75. Carl KM1H - Original Message - From: Charlie Cunningham charlie-cunning...@nc.rr.com To: 'ZR' z...@jeremy.mv.com; 'Carl Braun' carl.br...@lairdtech.com; '160' topband@contesting.com Sent: Friday, February 21, 2014 10:35 PM Subject: Re: Topband: Shunt feeding the Skyneedle - new developments Well, if I recall correctly, Carl, Carl said his feedline was about 70' of LMR-400, so even at 2 2:1 or 2.5:1 VSWR, the excess losses in 70' of LMR-400 at 1.8 MHz are almost 0, so if he can match it OK at the transmitter end of the line- no real point in making heroic efforts to achieve a perfect match! He'd gain more by working on his radial field, and he really should do that before doing any more tuning because improving the radials WILL affect the antenna impedance. 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of ZR Sent: Friday, February 21, 2014 10:11 PM To: Charlie Cunningham; 'Carl Braun'; '160' Subject: Re: Topband: Shunt feeding the Skyneedle - new developments The only benefit of getting it better would be a bit more 2:1 VSWR bandwidth to keep the amp happy but even then there is sometimes a gotcha when tuning an antenna. Carl KM1H Subject: Re: Topband: Shunt feeding the Skyneedle - new developments Well, you can do all that, Carl But if your series variable capacitor is not maxed out (fully meshed) if you can increase the capacitance enough to get to j0, you would be at 45 +j0 and on a 1.1:1 VSWR circle. No point int trying to do better than that!! Otherwise, just increase the series capacitance to bring that -j11 as close to j0 as possible and take that! You'd be so near perfect that there would be no real point in going further! Your time and efforts might be better spent working on your radial field! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carl Braun Sent: Friday, February 21, 2014 8:46 PM To: Charlie Cunningham; 'Tom W8JI'; '160' Subject: Re: Topband: Shunt feeding the Skyneedle - new developments Thanks to all who replied Tom W8JI, your comments on the metallic panel and the static bleed choke make sense. I was so pleased with the FLAT SWR reading with the variable cap outside the panel but I guess I can live with the slight SWR. (Thanks Charlie K4OTV). I have a Nye Viking monster tuner but I hate to use it as my Henry amp seems to load strangely when I have it inline so I think I'll just live without it. Can I add some coax (coiled) to bring the X down on the -j11 reading? I did this with the old Telrex and brought the X right down and out of the pic. I'm sure Ill need much more than I would on 14MHz but I think I'd like to try anyway. I'm still going to drop the tower down and add two more gamma wires to create a cage and I still have the option of pulling the gamma wire(s) away from the tower another 8-10 inches to add a few more ohms to the equation. I'm having fun with the experiment. Right now I'm hearing the beginnings of the SSB contest with N7GP, WD5COV, W6YI with the big signals so far. XE is the only DX I've heard. Lots of stateside calling stateside Carl AG6X -Original Message- From: Charlie Cunningham [mailto:charlie-cunning...@nc.rr.com] Sent: Friday, February 21, 2014 5:21 PM To: 'Tom W8JI'; Carl
Re: Topband: Shunt feeding the Skyneedle - new developments
Well, I agree with all that, Carl. But Carl Braun, was reading dead-flat 1:1 at the transmitter end of his cable. I believe he is done!! The antenna Q is what it is! As for improving his 2:1 VSWR bandwidth he could reduce his radial field and increase his ground losses to improve his 2:1 BW - but I believe that to be self-defeating!! I'm not missing your point - I just don't see what you'd change to improve on a flat line! Carl is well past the point of diminishing returns! The math doesn't lie! Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carl Sent: Saturday, February 22, 2014 10:41 AM To: Charlie Cunningham; 'Carl Braun'; '160' Subject: Re: Topband: Shunt feeding the Skyneedle - new developments Charlie youre continually missing the point; ignore cable loss period. The only issue is what impedance does the amp see from lets say 1800 to 1900 KHz? AND can the amp load into it without a problem at full power? This is a system issue, not just what is measured at the antenna and needs to be addressed that way. Put all that info into your program and post the results. Saying that a 1.3 VSWR at reasonance at the antenna is sufficient is too simplistic. Compute the VSWR at the amp with whatever length of coax is actually used over the lower 100 KHz with a range of at resonance VSWR's. Carl KM1H - Original Message - From: Charlie Cunningham charlie-cunning...@nc.rr.com To: 'Carl' k...@jeremy.mv.com; 'Carl Braun' carl.br...@lairdtech.com; '160' topband@contesting.com Sent: Saturday, February 22, 2014 9:57 AM Subject: RE: Topband: Shunt feeding the Skyneedle - new developments Well, Carl the looses in 70' or even 200' of LMR-400 are so low at 1.8 MHz, even at 2.0:1 or 3.0 :1, if he can match it at the transmitter end of the line, it really doesn't matter! Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carl Sent: Saturday, February 22, 2014 9:46 AM To: Charlie Cunningham; 'Carl Braun'; '160' Subject: Re: Topband: Shunt feeding the Skyneedle - new developments That 1.3 is only at ONE frequency Charlie, he is not crystal controlled. What is the 2:1 bandwidth at the amp? Carl KM1H - Original Message - From: Charlie Cunningham charlie-cunning...@nc.rr.com To: 'Carl' k...@jeremy.mv.com; 'Carl Braun' carl.br...@lairdtech.com; '160' topband@contesting.com Sent: Saturday, February 22, 2014 9:23 AM Subject: RE: Topband: Shunt feeding the Skyneedle - new developments I don't expect that ANY of those are valid concerns at 1.3:1 VSWR!! -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carl Sent: Saturday, February 22, 2014 9:14 AM To: Charlie Cunningham; 'Carl Braun'; '160' Subject: Re: Topband: Shunt feeding the Skyneedle - new developments Im not concerned by what is measured at the matching unit or a miniscule cable loss; just what is transformed back to the amp and its ability to load at full power without arcing, running out of or having too much fixed padder C during QSY's. Contests do not stay just in the narrow CW 50 KHz window and not having to use an external tuner is a big plus. Ive always modified my amps to work with my antennas on 160 and 80/75. Carl KM1H - Original Message - From: Charlie Cunningham charlie-cunning...@nc.rr.com To: 'ZR' z...@jeremy.mv.com; 'Carl Braun' carl.br...@lairdtech.com; '160' topband@contesting.com Sent: Friday, February 21, 2014 10:35 PM Subject: Re: Topband: Shunt feeding the Skyneedle - new developments Well, if I recall correctly, Carl, Carl said his feedline was about 70' of LMR-400, so even at 2 2:1 or 2.5:1 VSWR, the excess losses in 70' of LMR-400 at 1.8 MHz are almost 0, so if he can match it OK at the transmitter end of the line- no real point in making heroic efforts to achieve a perfect match! He'd gain more by working on his radial field, and he really should do that before doing any more tuning because improving the radials WILL affect the antenna impedance. 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of ZR Sent: Friday, February 21, 2014 10:11 PM To: Charlie Cunningham; 'Carl Braun'; '160' Subject: Re: Topband: Shunt feeding the Skyneedle - new developments The only benefit of getting it better would be a bit more 2:1 VSWR bandwidth to keep the amp happy but even then there is sometimes a gotcha when tuning an antenna. Carl KM1H Subject: Re: Topband: Shunt feeding the Skyneedle - new developments Well, you can do all that, Carl But if your series variable capacitor is not maxed out (fully meshed) if you can increase the capacitance enough to get to j0, you would be at 45 +j0 and on a 1.1:1 VSWR circle. No point int trying to do better than that!! Otherwise, just increase the series capacitance to bring that -j11 as close to j0 as possible and take that! You'd
Re: Topband: Shunt feeding the Skyneedle - new developments
Wel, I agree with all of that, Roger. I plotted Carl's 45-j11 load on a 50 ohm Smith Chart, and it's right near the origin of the chart on a 1.3:1 VSWR circle. I'd need some more data points at some other frequencies to plot to get a better picture of what's going on, But his VSWR is so low that the losses in 70' of LMR-400 on 160 are completely negligible! As long as he can match it at the transmitter end - no problem! And at one point, he was measuring dead-flat 1:1at the tranmitterend of the cable. His Henry amp should handle that just fine without a tuner! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Roger D Johnson Sent: Saturday, February 22, 2014 11:16 AM To: '160' Subject: Re: Topband: Shunt feeding the Skyneedle - new developments It may not be obvious but often you can get better bandwidth by NOT tuning for 1:1 at the desired frequency! Those familiar with the Smith chart probably already know this. A narrow band antenna will produce a curve between a U and a V on the Smith chart. If you tune for a 1:1 SWR, you bring the nose of the curve to the center of the chart. This often leaves the tails outside the desired SWR circle. If you continue until the nose goes to the opposite side of the SWR circle, it brings more of the tails into the circle. The resulting SWR curve is a W shape. It won't be 1:1 at any frequency but more of the curve will lie within the chosen SWR circle. 73, Roger On 2/22/2014 11:03 AM, Charlie Cunningham wrote: Well, I agree with all that, Carl. But Carl Braun, was reading dead-flat 1:1 at the transmitter end of his cable. I believe he is done!! The antenna Q is what it is! As for improving his 2:1 VSWR bandwidth he could reduce his radial field and increase his ground losses to improve his 2:1 BW - but I believe that to be self-defeating!! I'm not missing your point - I just don't see what you'd change to improve on a flat line! Carl is well past the point of diminishing returns! The math doesn't lie! Charlie, K4OTV _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Shunt feeding the Skyneedle - FB!
the cap is enclosed in a metallic enclosure vs sitting on a 5 gal plastic jug. ** No discussion needed there, thats been known for 100 years. It would also help to be more specific when presenting details, what does metallic really mean? The Henry amp seems to be OK with a little reactance so I'm going to concentrate on my gamma cage and radial system while waiting for RF Parts to deliver some necessary connectors. Once I get the PL259s installed I can replace my temp RG 58 jumper with the good stuff and then hit it with the Henry. I've kept the power below 500w during the contest so as not to stress the small coaxial cable. ** Good move. Carl KM1H 73 Carl Sent from my iPhone On Feb 22, 2014, at 8:42 AM, Carl k...@jeremy.mv.com wrote: I suppose I missed that part while doing things around here but this is the only pertinent info I can find from him. Nowhere does it say he has a 1:1 anywhere with the cap in the cabinet. Granted some of the posts are very confusing as to where things are being measured. -- The j11 ohms is the best I can get period. I was able to get j0 when the cap was outside of the steel enclosure with a better bandwidth. Maybe I should throw my $400 enclosure and find a fibergla$$ enclosure. But as others have indicated I should probably just live with it. The swr at my given freq as tuned with the variable cap is 1.3:1 or less...outside the enclosure the system had 1.0:1 swr readings and X=O over what appeared to be a broader bandwidth...even with 42 ohms at the feed point. -- So maybe you can explain where the 1.0 at the transmitter end with the cap in the box came from? Additionally the VSWR may/will change with added radials and ground moisture conditions. I'm going out for several hours so no rush on the answers. Carl KM1H - Original Message - From: Charlie Cunningham charlie-cunning...@nc.rr.com To: 'Carl' k...@jeremy.mv.com; 'Carl Braun' carl.br...@lairdtech.com; '160' topband@contesting.com Sent: Saturday, February 22, 2014 11:03 AM Subject: RE: Topband: Shunt feeding the Skyneedle - new developments Well, I agree with all that, Carl. But Carl Braun, was reading dead-flat 1:1 at the transmitter end of his cable. I believe he is done!! The antenna Q is what it is! As for improving his 2:1 VSWR bandwidth he could reduce his radial field and increase his ground losses to improve his 2:1 BW - but I believe that to be self-defeating!! I'm not missing your point - I just don't see what you'd change to improve on a flat line! Carl is well past the point of diminishing returns! The math doesn't lie! Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carl Sent: Saturday, February 22, 2014 10:41 AM To: Charlie Cunningham; 'Carl Braun'; '160' Subject: Re: Topband: Shunt feeding the Skyneedle - new developments Charlie youre continually missing the point; ignore cable loss period. The only issue is what impedance does the amp see from lets say 1800 to 1900 KHz? AND can the amp load into it without a problem at full power? This is a system issue, not just what is measured at the antenna and needs to be addressed that way. Put all that info into your program and post the results. Saying that a 1.3 VSWR at reasonance at the antenna is sufficient is too simplistic. Compute the VSWR at the amp with whatever length of coax is actually used over the lower 100 KHz with a range of at resonance VSWR's. Carl KM1H - Original Message - From: Charlie Cunningham charlie-cunning...@nc.rr.com To: 'Carl' k...@jeremy.mv.com; 'Carl Braun' carl.br...@lairdtech.com; '160' topband@contesting.com Sent: Saturday, February 22, 2014 9:57 AM Subject: RE: Topband: Shunt feeding the Skyneedle - new developments Well, Carl the looses in 70' or even 200' of LMR-400 are so low at 1.8 MHz, even at 2.0:1 or 3.0 :1, if he can match it at the transmitter end of the line, it really doesn't matter! Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carl Sent: Saturday, February 22, 2014 9:46 AM To: Charlie Cunningham; 'Carl Braun'; '160' Subject: Re: Topband: Shunt feeding the Skyneedle - new developments That 1.3 is only at ONE frequency Charlie, he is not crystal controlled. What is the 2:1 bandwidth at the amp? Carl KM1H - Original Message - From: Charlie Cunningham charlie-cunning...@nc.rr.com To: 'Carl' k...@jeremy.mv.com; 'Carl Braun' carl.br...@lairdtech.com; '160' topband@contesting.com Sent: Saturday, February 22, 2014 9:23 AM Subject: RE: Topband: Shunt feeding the Skyneedle - new developments I don't expect that ANY of those are valid concerns at 1.3:1 VSWR!! -Original Message- From: Topband [mailto:topband
Re: Topband: Shunt feeding the Skyneedle - new developments
Exactly! All true and Tom is right on point! You have removed a lot of series reactance with that gamma cage, Carl -as indicated by the required tuning C changing.from 160 pF ot over 400 pF. OF COURSE the Q was reduced as the series reactance was reduced and the real part stayed fairly constant. That does not imply increased or excessive loss! Regards Charlie -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Tom W8JI Sent: Saturday, February 22, 2014 9:07 PM To: Carl Braun; '160' Subject: Re: Topband: Shunt feeding the Skyneedle - new developments I was pretty satisfied with this scenario so I mounted my variable cap on a 3/4 thick piece of Plexiglas to the backplane via Teflon bolts inside the steel enclosure. When I did this I saw my analyzer jump to 45 -j11 ohms. No matter how much tweaking was done the lowest X on the analyzer was 11. Figuring I could live with that after making 24 contacts this morning I decided to move ahead with my gamma cage. When I completed the cage per the info above I left my analyzer set on the previous frequency setting of 1825 and saw the resistance jump and the X go out of site. Adjusting my variable cap (from approx 140 pf to 420 pf) rewarded me with a 42 + j0 reading. Inside the shack on the 1000D and the BIRD I see 1.1:1 Vswr at 1.800 MHz, FLAT 1.0:1 from 1.810 to 1.860 and 1.5:1 at 1.895 MHz. I would expect you to have that bandwidth. It does NOT indicate loss. Your shunt system now has an operating Q of around 4, because you now have 200 ohms of series C. With a thick radiator and a large yagi on top, and so much capacitance, you are exactly on target. While I don't fully trust the FT1000 meter, no matter what, never automatically assume modest bandwidth like you have indicates loss. It doesn't. There are a whole lot of things that go into bandwidth beside loss! 73 Tom _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Shunt feeding the Skyneedle - new developments
:1 from 1.810 to 1.860 and 1.5:1 at 1.895 MHz. I'm eager to get back on the air tonight and tomorrow morning to see how it plays 73 Carl AG6X -Original Message- From: Carl [mailto:k...@jeremy.mv.com] Sent: Saturday, February 22, 2014 1:22 PM To: Carl Braun Subject: Re: Topband: Shunt feeding the Skyneedle - new developments Subject: Re: Topband: Shunt feeding the Skyneedle - new developments The measurements are being taken, and have been taken, at the same point since the beginning of the antenna experiment. ** How about refreshing my merory about those details Carl? Frequency also. I wasnt involved in the early parts and deleted them already. The ONLY difference is that the variable cap is now mounted inside the steel panel as described in my previous posts, instead of outside the panel, as described in previous posts. Same length of wire each scenario. I believe Tom W8JI called it when he stated that a change was likely when the cap is enclosed in a metallic enclosure vs sitting on a 5 gal plastic jug. ** No discussion needed there, thats been known for 100 years. It would also help to be more specific when presenting details, what does metallic really mean? The Henry amp seems to be OK with a little reactance so I'm going to concentrate on my gamma cage and radial system while waiting for RF Parts to deliver some necessary connectors. Once I get the PL259s installed I can replace my temp RG 58 jumper with the good stuff and then hit it with the Henry. I've kept the power below 500w during the contest so as not to stress the small coaxial cable. ** Good move. Carl KM1H 73 Carl Sent from my iPhone On Feb 22, 2014, at 8:42 AM, Carl k...@jeremy.mv.com wrote: I suppose I missed that part while doing things around here but this is the only pertinent info I can find from him. Nowhere does it say he has a 1:1 anywhere with the cap in the cabinet. Granted some of the posts are very confusing as to where things are being measured. -- The j11 ohms is the best I can get period. I was able to get j0 when the cap was outside of the steel enclosure with a better bandwidth. Maybe I should throw my $400 enclosure and find a fibergla$$ enclosure. But as others have indicated I should probably just live with it. The swr at my given freq as tuned with the variable cap is 1.3:1 or less...outside the enclosure the system had 1.0:1 swr readings and X=O over what appeared to be a broader bandwidth...even with 42 ohms at the feed point. -- So maybe you can explain where the 1.0 at the transmitter end with the cap in the box came from? Additionally the VSWR may/will change with added radials and ground moisture conditions. I'm going out for several hours so no rush on the answers. Carl KM1H - Original Message - From: Charlie Cunningham charlie-cunning...@nc.rr.com To: 'Carl' k...@jeremy.mv.com; 'Carl Braun' carl.br...@lairdtech.com; '160' topband@contesting.com Sent: Saturday, February 22, 2014 11:03 AM Subject: RE: Topband: Shunt feeding the Skyneedle - new developments Well, I agree with all that, Carl. But Carl Braun, was reading dead-flat 1:1 at the transmitter end of his cable. I believe he is done!! The antenna Q is what it is! As for improving his 2:1 VSWR bandwidth he could reduce his radial field and increase his ground losses to improve his 2:1 BW - but I believe that to be self-defeating!! I'm not missing your point - I just don't see what you'd change to improve on a flat line! Carl is well past the point of diminishing returns! The math doesn't lie! Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carl Sent: Saturday, February 22, 2014 10:41 AM To: Charlie Cunningham; 'Carl Braun'; '160' Subject: Re: Topband: Shunt feeding the Skyneedle - new developments Charlie youre continually missing the point; ignore cable loss period. The only issue is what impedance does the amp see from lets say 1800 to 1900 KHz? AND can the amp load into it without a problem at full power? This is a system issue, not just what is measured at the antenna and needs to be addressed that way. Put all that info into your program and post the results. Saying that a 1.3 VSWR at reasonance at the antenna is sufficient is too simplistic. Compute the VSWR at the amp with whatever length of coax is actually used over the lower 100 KHz with a range of at resonance VSWR's. Carl KM1H - Original Message - From: Charlie Cunningham charlie-cunning...@nc.rr.com To: 'Carl' k...@jeremy.mv.com; 'Carl Braun' carl.br...@lairdtech.com; '160' topband@contesting.com Sent: Saturday, February 22, 2014 9:57 AM Subject: RE: Topband: Shunt feeding the Skyneedle - new developments Well, Carl the looses in 70' or even 200' of LMR-400 are so low at 1.8 MHz, even
Re: Topband: Shunt feeding the Skyneedle - new developments
Well, Carl I plotted your 45-j11 load on a Smith Chart (normalized to 50 ohms) and it's very near the origin on a 1.3:1 VSWR circle. Since you have a relatively short feedline of LMR-400, You should be able to just tune it out at the transmitter end of the line, and the LMR-400 line will be operating at such a very low SWR (around 1.3:1 that the excess loss from a 1.3:1 VSWR at 160 is completely trivial and negligible! It may not be completely intellectually satisfying to have -j11 of reactance at the load, but it should match easily and the antenna should work very well! Enjoy! Sounds like that Array solutions static bleed is not as high in impedance as we might wish! A large resistance might give you more satisfactory results! GL! Enjoy! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Tom W8JI Sent: Friday, February 21, 2014 8:02 PM To: Carl Braun; '160' Subject: Re: Topband: Shunt feeding the Skyneedle - new developments Since then I've moved the variable capacitor inside the panel and mounted it to a ¾ think Plexiglas sheet mounted to the back plane with nylon bolts and washers. There is a 1 air gap between the Plexiglas and the backplane. I now have seen the 42+j0 ohms change to 45 - j11 ohms...that's the lowest reactance I can tune the capacitor for. Not really sure if its +j11 ohms or - j11 ohms but I assume if the reading was + j11 I could continue to tune it out with the capacitor but I cant. Does the capacitor not play well with a steel enclosure? Any enclosure will change things, especially a metallic enclosure. Just readjust the cap. The other strange situation I'm experiencing is when I connect my Array Solutions static bleed choke to the feed thru insulator at the outside of the panel to ground the resonant frequency jumps to 2.014 MHz at 25 +j0 ohms...remove it entirely and I'm back to my 45 - j11 ohms. The choke is completely unnecessary with a shunt feed tower. It won't help a thing, so leave it out. 73 Tom _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Shunt feeding the Skyneedle - new developments BTW
BTW. Carl I agree completely with Tom that there's no point in having a static-bleed choke on a grounded shunt fed tower! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Tom W8JI Sent: Friday, February 21, 2014 8:02 PM To: Carl Braun; '160' Subject: Re: Topband: Shunt feeding the Skyneedle - new developments Since then I've moved the variable capacitor inside the panel and mounted it to a ¾ think Plexiglas sheet mounted to the back plane with nylon bolts and washers. There is a 1 air gap between the Plexiglas and the backplane. I now have seen the 42+j0 ohms change to 45 - j11 ohms...that's the lowest reactance I can tune the capacitor for. Not really sure if its +j11 ohms or - j11 ohms but I assume if the reading was + j11 I could continue to tune it out with the capacitor but I cant. Does the capacitor not play well with a steel enclosure? Any enclosure will change things, especially a metallic enclosure. Just readjust the cap. The other strange situation I'm experiencing is when I connect my Array Solutions static bleed choke to the feed thru insulator at the outside of the panel to ground the resonant frequency jumps to 2.014 MHz at 25 +j0 ohms...remove it entirely and I'm back to my 45 - j11 ohms. The choke is completely unnecessary with a shunt feed tower. It won't help a thing, so leave it out. 73 Tom _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Shunt feeding the Skyneedle - new developments BTW-P.S.
By the way, Carl. it sounds like you might have eliminated a bit of series inductance when you moved the variable capacitor into the enclosure and you may have picked up a bit of shunt-C by moving it into the metallic enclosure, but you are so close to dead-flat 1:1, that it really doesn't matter. You could just tweak the variable C to minimize the reactance at the load, but -j11 is just fine! As I said earlier your 45-j11 resides near the origin of the chart on a 1.3:1 VSWR circle! Enjoy and have fun! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Charlie Cunningham Sent: Friday, February 21, 2014 8:30 PM To: 'Tom W8JI'; 'Carl Braun'; '160' Subject: Re: Topband: Shunt feeding the Skyneedle - new developments BTW BTW. Carl I agree completely with Tom that there's no point in having a static-bleed choke on a grounded shunt fed tower! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Tom W8JI Sent: Friday, February 21, 2014 8:02 PM To: Carl Braun; '160' Subject: Re: Topband: Shunt feeding the Skyneedle - new developments Since then I've moved the variable capacitor inside the panel and mounted it to a ¾ think Plexiglas sheet mounted to the back plane with nylon bolts and washers. There is a 1 air gap between the Plexiglas and the backplane. I now have seen the 42+j0 ohms change to 45 - j11 ohms...that's the lowest reactance I can tune the capacitor for. Not really sure if its +j11 ohms or - j11 ohms but I assume if the reading was + j11 I could continue to tune it out with the capacitor but I cant. Does the capacitor not play well with a steel enclosure? Any enclosure will change things, especially a metallic enclosure. Just readjust the cap. The other strange situation I'm experiencing is when I connect my Array Solutions static bleed choke to the feed thru insulator at the outside of the panel to ground the resonant frequency jumps to 2.014 MHz at 25 +j0 ohms...remove it entirely and I'm back to my 45 - j11 ohms. The choke is completely unnecessary with a shunt feed tower. It won't help a thing, so leave it out. 73 Tom _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Shunt feeding the Skyneedle - new developments
I'd think your Henry would match that just fine WITHOUT the Nye Viking tuner!! 73, Charlie. K4OTV -Original Message- From: Carl Braun [mailto:carl.br...@lairdtech.com] Sent: Friday, February 21, 2014 8:46 PM To: Charlie Cunningham; 'Tom W8JI'; '160' Subject: RE: Topband: Shunt feeding the Skyneedle - new developments Thanks to all who replied Tom W8JI, your comments on the metallic panel and the static bleed choke make sense. I was so pleased with the FLAT SWR reading with the variable cap outside the panel but I guess I can live with the slight SWR. (Thanks Charlie K4OTV). I have a Nye Viking monster tuner but I hate to use it as my Henry amp seems to load strangely when I have it inline so I think I'll just live without it. Can I add some coax (coiled) to bring the X down on the -j11 reading? I did this with the old Telrex and brought the X right down and out of the pic. I'm sure Ill need much more than I would on 14MHz but I think I'd like to try anyway. I'm still going to drop the tower down and add two more gamma wires to create a cage and I still have the option of pulling the gamma wire(s) away from the tower another 8-10 inches to add a few more ohms to the equation. I'm having fun with the experiment. Right now I'm hearing the beginnings of the SSB contest with N7GP, WD5COV, W6YI with the big signals so far. XE is the only DX I've heard. Lots of stateside calling stateside Carl AG6X -Original Message- From: Charlie Cunningham [mailto:charlie-cunning...@nc.rr.com] Sent: Friday, February 21, 2014 5:21 PM To: 'Tom W8JI'; Carl Braun; '160' Subject: RE: Topband: Shunt feeding the Skyneedle - new developments Well, Carl I plotted your 45-j11 load on a Smith Chart (normalized to 50 ohms) and it's very near the origin on a 1.3:1 VSWR circle. Since you have a relatively short feedline of LMR-400, You should be able to just tune it out at the transmitter end of the line, and the LMR-400 line will be operating at such a very low SWR (around 1.3:1 that the excess loss from a 1.3:1 VSWR at 160 is completely trivial and negligible! It may not be completely intellectually satisfying to have -j11 of reactance at the load, but it should match easily and the antenna should work very well! Enjoy! Sounds like that Array solutions static bleed is not as high in impedance as we might wish! A large resistance might give you more satisfactory results! GL! Enjoy! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Tom W8JI Sent: Friday, February 21, 2014 8:02 PM To: Carl Braun; '160' Subject: Re: Topband: Shunt feeding the Skyneedle - new developments Since then I've moved the variable capacitor inside the panel and mounted it to a ¾ think Plexiglas sheet mounted to the back plane with nylon bolts and washers. There is a 1 air gap between the Plexiglas and the backplane. I now have seen the 42+j0 ohms change to 45 - j11 ohms...that's the lowest reactance I can tune the capacitor for. Not really sure if its +j11 ohms or - j11 ohms but I assume if the reading was + j11 I could continue to tune it out with the capacitor but I cant. Does the capacitor not play well with a steel enclosure? Any enclosure will change things, especially a metallic enclosure. Just readjust the cap. The other strange situation I'm experiencing is when I connect my Array Solutions static bleed choke to the feed thru insulator at the outside of the panel to ground the resonant frequency jumps to 2.014 MHz at 25 +j0 ohms...remove it entirely and I'm back to my 45 - j11 ohms. The choke is completely unnecessary with a shunt feed tower. It won't help a thing, so leave it out. 73 Tom _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Shunt feeding the Skyneedle - new developments
Well, if I recall correctly, Carl, Carl said his feedline was about 70' of LMR-400, so even at 2 2:1 or 2.5:1 VSWR, the excess losses in 70' of LMR-400 at 1.8 MHz are almost 0, so if he can match it OK at the transmitter end of the line- no real point in making heroic efforts to achieve a perfect match! He'd gain more by working on his radial field, and he really should do that before doing any more tuning because improving the radials WILL affect the antenna impedance. 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of ZR Sent: Friday, February 21, 2014 10:11 PM To: Charlie Cunningham; 'Carl Braun'; '160' Subject: Re: Topband: Shunt feeding the Skyneedle - new developments The only benefit of getting it better would be a bit more 2:1 VSWR bandwidth to keep the amp happy but even then there is sometimes a gotcha when tuning an antenna. Carl KM1H Subject: Re: Topband: Shunt feeding the Skyneedle - new developments Well, you can do all that, Carl But if your series variable capacitor is not maxed out (fully meshed) if you can increase the capacitance enough to get to j0, you would be at 45 +j0 and on a 1.1:1 VSWR circle. No point int trying to do better than that!! Otherwise, just increase the series capacitance to bring that -j11 as close to j0 as possible and take that! You'd be so near perfect that there would be no real point in going further! Your time and efforts might be better spent working on your radial field! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carl Braun Sent: Friday, February 21, 2014 8:46 PM To: Charlie Cunningham; 'Tom W8JI'; '160' Subject: Re: Topband: Shunt feeding the Skyneedle - new developments Thanks to all who replied Tom W8JI, your comments on the metallic panel and the static bleed choke make sense. I was so pleased with the FLAT SWR reading with the variable cap outside the panel but I guess I can live with the slight SWR. (Thanks Charlie K4OTV). I have a Nye Viking monster tuner but I hate to use it as my Henry amp seems to load strangely when I have it inline so I think I'll just live without it. Can I add some coax (coiled) to bring the X down on the -j11 reading? I did this with the old Telrex and brought the X right down and out of the pic. I'm sure Ill need much more than I would on 14MHz but I think I'd like to try anyway. I'm still going to drop the tower down and add two more gamma wires to create a cage and I still have the option of pulling the gamma wire(s) away from the tower another 8-10 inches to add a few more ohms to the equation. I'm having fun with the experiment. Right now I'm hearing the beginnings of the SSB contest with N7GP, WD5COV, W6YI with the big signals so far. XE is the only DX I've heard. Lots of stateside calling stateside Carl AG6X -Original Message- From: Charlie Cunningham [mailto:charlie-cunning...@nc.rr.com] Sent: Friday, February 21, 2014 5:21 PM To: 'Tom W8JI'; Carl Braun; '160' Subject: RE: Topband: Shunt feeding the Skyneedle - new developments Well, Carl I plotted your 45-j11 load on a Smith Chart (normalized to 50 ohms) and it's very near the origin on a 1.3:1 VSWR circle. Since you have a relatively short feedline of LMR-400, You should be able to just tune it out at the transmitter end of the line, and the LMR-400 line will be operating at such a very low SWR (around 1.3:1 that the excess loss from a 1.3:1 VSWR at 160 is completely trivial and negligible! It may not be completely intellectually satisfying to have -j11 of reactance at the load, but it should match easily and the antenna should work very well! Enjoy! Sounds like that Array solutions static bleed is not as high in impedance as we might wish! A large resistance might give you more satisfactory results! GL! Enjoy! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Tom W8JI Sent: Friday, February 21, 2014 8:02 PM To: Carl Braun; '160' Subject: Re: Topband: Shunt feeding the Skyneedle - new developments Since then I've moved the variable capacitor inside the panel and mounted it to a ¾ think Plexiglas sheet mounted to the back plane with nylon bolts and washers. There is a 1 air gap between the Plexiglas and the backplane. I now have seen the 42+j0 ohms change to 45 - j11 ohms...that's the lowest reactance I can tune the capacitor for. Not really sure if its +j11 ohms or - j11 ohms but I assume if the reading was + j11 I could continue to tune it out with the capacitor but I cant. Does the capacitor not play well with a steel enclosure? Any enclosure will change things, especially a metallic enclosure. Just readjust the cap. The other strange situation I'm experiencing is when I connect my Array Solutions static bleed choke to the feed thru insulator at the outside of the panel to ground the resonant frequency jumps
Re: Topband: Shunt feeding the Skyneedle - new developments
Well, Carl, you might pick up a littie less shunt C with the vacuum variable, and if it will provide more capacitance, it will probably allow you to get to j0. I guess if you don't have some other need for the high voltage capability of the vacuum variable, It should surely do the job! If you are at -j11, that means you have tken out enough inductance from the gamma line that you now need a larger capacitor to resonate it. Have fun! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carl Braun Sent: Friday, February 21, 2014 10:31 PM To: ZR Cc: Charlie Cunningham; 160 Subject: Re: Topband: Shunt feeding the Skyneedle - new developments Thanks guys The j11 ohms is the best I can get period. I was able to get j0 when the cap was outside of the steel enclosure with a better bandwidth. Maybe I should throw my $400 enclosure and find a fibergla$$ enclosure. But as others have indicated I should probably just live with it. Do you think a smaller (physically) vacuum cap would have less interaction with the steel enclosure. The one I have is only 3 round and 6 long. The air variable I'm using is 13 long and 7 round at mesh Carl AG6X Sent from my iPhone On Feb 21, 2014, at 7:11 PM, ZR z...@jeremy.mv.com wrote: The only benefit of getting it better would be a bit more 2:1 VSWR bandwidth to keep the amp happy but even then there is sometimes a gotcha when tuning an antenna. Carl KM1H Subject: Re: Topband: Shunt feeding the Skyneedle - new developments Well, you can do all that, Carl But if your series variable capacitor is not maxed out (fully meshed) if you can increase the capacitance enough to get to j0, you would be at 45 +j0 and on a 1.1:1 VSWR circle. No point int trying to do better than that!! Otherwise, just increase the series capacitance to bring that -j11 as close to j0 as possible and take that! You'd be so near perfect that there would be no real point in going further! Your time and efforts might be better spent working on your radial field! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carl Braun Sent: Friday, February 21, 2014 8:46 PM To: Charlie Cunningham; 'Tom W8JI'; '160' Subject: Re: Topband: Shunt feeding the Skyneedle - new developments Thanks to all who replied Tom W8JI, your comments on the metallic panel and the static bleed choke make sense. I was so pleased with the FLAT SWR reading with the variable cap outside the panel but I guess I can live with the slight SWR. (Thanks Charlie K4OTV). I have a Nye Viking monster tuner but I hate to use it as my Henry amp seems to load strangely when I have it inline so I think I'll just live without it. Can I add some coax (coiled) to bring the X down on the -j11 reading? I did this with the old Telrex and brought the X right down and out of the pic. I'm sure Ill need much more than I would on 14MHz but I think I'd like to try anyway. I'm still going to drop the tower down and add two more gamma wires to create a cage and I still have the option of pulling the gamma wire(s) away from the tower another 8-10 inches to add a few more ohms to the equation. I'm having fun with the experiment. Right now I'm hearing the beginnings of the SSB contest with N7GP, WD5COV, W6YI with the big signals so far. XE is the only DX I've heard. Lots of stateside calling stateside Carl AG6X -Original Message- From: Charlie Cunningham [mailto:charlie-cunning...@nc.rr.com] Sent: Friday, February 21, 2014 5:21 PM To: 'Tom W8JI'; Carl Braun; '160' Subject: RE: Topband: Shunt feeding the Skyneedle - new developments Well, Carl I plotted your 45-j11 load on a Smith Chart (normalized to 50 ohms) and it's very near the origin on a 1.3:1 VSWR circle. Since you have a relatively short feedline of LMR-400, You should be able to just tune it out at the transmitter end of the line, and the LMR-400 line will be operating at such a very low SWR (around 1.3:1 that the excess loss from a 1.3:1 VSWR at 160 is completely trivial and negligible! It may not be completely intellectually satisfying to have -j11 of reactance at the load, but it should match easily and the antenna should work very well! Enjoy! Sounds like that Array solutions static bleed is not as high in impedance as we might wish! A large resistance might give you more satisfactory results! GL! Enjoy! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Tom W8JI Sent: Friday, February 21, 2014 8:02 PM To: Carl Braun; '160' Subject: Re: Topband: Shunt feeding the Skyneedle - new developments Since then I've moved the variable capacitor inside the panel and mounted it to a ¾ think Plexiglas sheet mounted to the back plane with nylon bolts and washers. There is a 1 air gap between
Re: Topband: Shunt feeding the Skyneedle - new developments
Well, that would surely suggest that you should be able to reach j0, by increasing the series capacitance, Carl, unless there's a shunt-C term that has entered the picture after mouning that big variable capacitor in the metallic enclosure. But, again, why bother! 73, Charlie, K4OTV -Original Message- From: Carl Braun [mailto:carl.br...@lairdtech.com] Sent: Friday, February 21, 2014 10:39 PM To: Charlie Cunningham; 'Tom W8JI'; '160' Subject: RE: Topband: Shunt feeding the Skyneedle - new developments Charlie The cap is no where near maxed out. I'm using approx 150pf of a 1050pf variable cap. Carl -Original Message- From: Charlie Cunningham [mailto:charlie-cunning...@nc.rr.com] Sent: Friday, February 21, 2014 6:37 PM To: Carl Braun; 'Tom W8JI'; '160' Subject: RE: Topband: Shunt feeding the Skyneedle - new developments Well, you can do all that, Carl But if your series variable capacitor is not maxed out (fully meshed) if you can increase the capacitance enough to get to j0, you would be at 45 +j0 and on a 1.1:1 VSWR circle. No point int trying to do better than that!! Otherwise, just increase the series capacitance to bring that -j11 as close to j0 as possible and take that! You'd be so near perfect that there would be no real point in going further! Your time and efforts might be better spent working on your radial field! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carl Braun Sent: Friday, February 21, 2014 8:46 PM To: Charlie Cunningham; 'Tom W8JI'; '160' Subject: Re: Topband: Shunt feeding the Skyneedle - new developments Thanks to all who replied Tom W8JI, your comments on the metallic panel and the static bleed choke make sense. I was so pleased with the FLAT SWR reading with the variable cap outside the panel but I guess I can live with the slight SWR. (Thanks Charlie K4OTV). I have a Nye Viking monster tuner but I hate to use it as my Henry amp seems to load strangely when I have it inline so I think I'll just live without it. Can I add some coax (coiled) to bring the X down on the -j11 reading? I did this with the old Telrex and brought the X right down and out of the pic. I'm sure Ill need much more than I would on 14MHz but I think I'd like to try anyway. I'm still going to drop the tower down and add two more gamma wires to create a cage and I still have the option of pulling the gamma wire(s) away from the tower another 8-10 inches to add a few more ohms to the equation. I'm having fun with the experiment. Right now I'm hearing the beginnings of the SSB contest with N7GP, WD5COV, W6YI with the big signals so far. XE is the only DX I've heard. Lots of stateside calling stateside Carl AG6X -Original Message- From: Charlie Cunningham [mailto:charlie-cunning...@nc.rr.com] Sent: Friday, February 21, 2014 5:21 PM To: 'Tom W8JI'; Carl Braun; '160' Subject: RE: Topband: Shunt feeding the Skyneedle - new developments Well, Carl I plotted your 45-j11 load on a Smith Chart (normalized to 50 ohms) and it's very near the origin on a 1.3:1 VSWR circle. Since you have a relatively short feedline of LMR-400, You should be able to just tune it out at the transmitter end of the line, and the LMR-400 line will be operating at such a very low SWR (around 1.3:1 that the excess loss from a 1.3:1 VSWR at 160 is completely trivial and negligible! It may not be completely intellectually satisfying to have -j11 of reactance at the load, but it should match easily and the antenna should work very well! Enjoy! Sounds like that Array solutions static bleed is not as high in impedance as we might wish! A large resistance might give you more satisfactory results! GL! Enjoy! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Tom W8JI Sent: Friday, February 21, 2014 8:02 PM To: Carl Braun; '160' Subject: Re: Topband: Shunt feeding the Skyneedle - new developments Since then I've moved the variable capacitor inside the panel and mounted it to a ¾ think Plexiglas sheet mounted to the back plane with nylon bolts and washers. There is a 1 air gap between the Plexiglas and the backplane. I now have seen the 42+j0 ohms change to 45 - j11 ohms...that's the lowest reactance I can tune the capacitor for. Not really sure if its +j11 ohms or - j11 ohms but I assume if the reading was + j11 I could continue to tune it out with the capacitor but I cant. Does the capacitor not play well with a steel enclosure? Any enclosure will change things, especially a metallic enclosure. Just readjust the cap. The other strange situation I'm experiencing is when I connect my Array Solutions static bleed choke to the feed thru insulator at the outside of the panel to ground the resonant frequency jumps to 2.014 MHz at 25 +j0 ohms...remove it entirely and I'm back to my 45 - j11 ohms. The choke is completely unnecessary with a shunt feed tower
Re: Topband: Shunt feeding the Skyneedle - new developments
Hi, Carl Well, I think that what you are doing with your radials should be OK. I guess I'd rather get them under the asphalt if I could where they wouldn't get torn up or b a trip hazard. BTW I I was playing with your match on the Smith Chart and if you'll add about 1 uHy inductance in series with the connector (SO-239?) where you feedline leaves the enclosure, that will take you to 45 +j0, but I'd be concerned about incurring more losses in the inductor than any tiny mismatch loss from the -j11 term. I probably wouldn't do it. 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carl Braun Sent: Friday, February 21, 2014 10:56 PM To: Charlie Cunningham; 'ZR'; '160' Subject: Re: Topband: Shunt feeding the Skyneedle - new developments I'm working on the radial field weekly. Here is a theoretical question that results from my particular QTH. The Skyneedle is situated near a secondary blacktop driveway that is in the back of my property. I have to run radials over the blacktop to the rest of the property and, in order to keep things kind of neat, I'm using multi-conductor rotor cable as radials that travel over the blacktop. I have both 6 conductor and 3 conductor control cable that I'm using. I strip back the jacket at the radial ring...fan out the wires 3 apart and attach them to the 1 1/2 copper pipe I'm using as a radial ring around the base of the 'Needle'. Then the radial wires converge back into the cable jacket then travel across the 10' blacktop driveway and then they are removed from the cable jacket where they fan out into the dirt and are buried. Most of these radial wires are 60' to 100' once they leave the jacket. Any problem with what I'm doing here? I understand that it would be better if they fanned out directly from the base but I can have 50+ wires traveling over the blacktop. I was even considering getting an asphalt blade and cutting some channels into the blacktop...burying the jacketed cable into the asphalt and then sealing then in so I'm not running over them or tripping over them when playing Frisbee with the hound. My Guatemalan yard worker has been burying radial wires for the last month and thinks that I'm LOCO but he likes getting paid at the end of the day. As we speak I have a total of 34 radials with the shortest being 30' with the longest at 100'. Most of them are 60-70'. Four of them are tied into my 40m phased array radial field comprised of 90-100 radials under each antenna ranging from 40' to 80'. I can change the height of these verticals from 33' for 40m to 66' for 80m. 1/2 wl spacing on 40 and 1/4 wl spacing on 80. Carl AG6X -Original Message- From: Charlie Cunningham [mailto:charlie-cunning...@nc.rr.com] Sent: Friday, February 21, 2014 7:36 PM To: 'ZR'; Carl Braun; '160' Subject: RE: Topband: Shunt feeding the Skyneedle - new developments Well, if I recall correctly, Carl, Carl said his feedline was about 70' of LMR-400, so even at 2 2:1 or 2.5:1 VSWR, the excess losses in 70' of LMR-400 at 1.8 MHz are almost 0, so if he can match it OK at the transmitter end of the line- no real point in making heroic efforts to achieve a perfect match! He'd gain more by working on his radial field, and he really should do that before doing any more tuning because improving the radials WILL affect the antenna impedance. 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of ZR Sent: Friday, February 21, 2014 10:11 PM To: Charlie Cunningham; 'Carl Braun'; '160' Subject: Re: Topband: Shunt feeding the Skyneedle - new developments The only benefit of getting it better would be a bit more 2:1 VSWR bandwidth to keep the amp happy but even then there is sometimes a gotcha when tuning an antenna. Carl KM1H Subject: Re: Topband: Shunt feeding the Skyneedle - new developments Well, you can do all that, Carl But if your series variable capacitor is not maxed out (fully meshed) if you can increase the capacitance enough to get to j0, you would be at 45 +j0 and on a 1.1:1 VSWR circle. No point int trying to do better than that!! Otherwise, just increase the series capacitance to bring that -j11 as close to j0 as possible and take that! You'd be so near perfect that there would be no real point in going further! Your time and efforts might be better spent working on your radial field! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carl Braun Sent: Friday, February 21, 2014 8:46 PM To: Charlie Cunningham; 'Tom W8JI'; '160' Subject: Re: Topband: Shunt feeding the Skyneedle - new developments Thanks to all who replied Tom W8JI, your comments on the metallic panel and the static bleed choke make sense. I was so pleased with the FLAT SWR reading with the variable cap outside the panel but I guess I can live with the slight SWR. (Thanks Charlie K4OTV). I have
Re: Topband: 160 condx....2nd CME impact
Interesting! Thanks for sharing, Bruce! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Bruce Sent: Thursday, February 20, 2014 2:16 PM To: topband@contesting.com Subject: Topband: 160 condx2nd CME impact http://www.spaceweather.com/ 73 Bruce-K1FZ www.qsl.net/k1fz/pennantnotes.html Flag, Pennant, Delta receiving antenna info. _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Coax issues - BTW
BTW, Gary Are you using crimp-on connectors on your coax? 73, Charlie, K4OTV -Original Message- From: Tom W8JI [mailto:w...@w8ji.com] Sent: Wednesday, February 19, 2014 12:21 PM To: Jim F.; Charlie Cunningham; g...@ka1j.com; Topband@contesting.com Subject: Re: Topband: Coax issues It does not matter if he recorded something or not, the 259B will find the fault location. - Original Message - From: Jim F. j_fit...@yahoo.com To: Charlie Cunningham charlie-cunning...@nc.rr.com; g...@ka1j.com; Topband@contesting.com Sent: Wednesday, February 19, 2014 11:30 AM Subject: Re: Topband: Coax issues Gary, I would try it on a spare length of coax first to get the hang of it. I tried measuring a length of coax using a square wave generator and a scope and was surprised at the accuracy. 73 W1FMR On Wednesday, February 19, 2014 11:16 AM, Charlie Cunningham charlie-cunning...@nc.rr.com wrote: Hi, Gary! I hope you've measured the antenna directly with your MFJ 259B with the coax disconnected to be sure that the antenna hasn't changed in some way. Think I'd check that (if you haven't already) before undertaking any heroic fault-finding measures, After that, I'd probably bet on the connector at the remote (antenna) end of the cable. GL and take care! ( I also have a bad right foot, so I can empathize!) ' 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Gary Smith Sent: Wednesday, February 19, 2014 10:26 AM To: Topband@contesting.com Subject: Re: Topband: Coax issues Thank you all for the replies, I didn't know the 259B will do this. I'm off to remove the antenna from the coax and will come back in try and follow the directions in the manual I downloaded. I bought the 259B on fleabay as a LCD replacement to the MFJ-207 SWR analyzer for pruning my antenna wires and I've never used it for anything else. Silver lining: This is a perfect day a test of my Weller PSI100K Portasol butane soldering iron I got last summer. I've got a couple hand warmers started to keep the butane warm while I'm outside, the butane pressure drops with cold temps. I don't have 350 feet of extension cord and could never repair it outside without something portable. Here's hoping it's not to hard to follow the instructions accurately, find the bugger then resolve. I've got a bad right foot so the less trips out into the snow will make it easier on me. thanks! Gary KA1J --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband - No virus found in this message. Checked by AVG - www.avg.com Version: 2014.0.4259 / Virus Database: 3705/7106 - Release Date: 02/19/14 _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Coax issues
FB. Gary! Glad you got it resolved! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Gary Smith Sent: Wednesday, February 19, 2014 2:05 PM To: Topband@contesting.com Subject: Re: Topband: Coax issues Resolution: Eat more rabbit. Thanks again for the pointer to the 259B being an answer. I now see it will do more than I knew, I didn't know about the advanced mode. So... Last night I disconnected the coax in to the distal coax switch, it was not connected in the shack but I read a dead short with the fluke. This morning I went out and disconnected the coax so I could make a reading on both ends of the coax to see how well they jived. Found the instigator of the problem that damned rabbit chewed mostly through the control cable to the coax switch. He must have bit into the voltage that stopped him. However, he had chewed through the cable and had severed 3-4 wires of the 6 involved in switching and this disconnected the coax from the antenna. I was trying for 3B9/OE4AAC on Rodriguez on 17 using the amp. Amazingly the amp didn't have any issue but that energy had to go somewhere. I reattached the control wires at the switch, went back to the shack and read 515 feet to fault and that multiplied by the VF of .66 = 334 feet. Not knowing the exact footage of the coax, I went to the distal end and remeasured from there and kept getting different distances but one thing was for sure, it was easier getting the zero readings at the shack end. I cut off the connector there still was a dead short in the coax so I cut away the roll of coax I used for a choke thinking it would be found there but no. I started the long grind of pulling up the coax from under the leaves snow came to something I'd forgotten about, I had run short of coax and needed to use a female/female jumper to add a length of coax to reach the switch box. I undid the sealant could smell the burn. The end going to the house was undamaged but the other end had fried at the connector. I'd forgotten that the last part was foam coax my long run used the hard plastic dielectric; it was the foam that melted shorted. All's well now with the coax and antennas, all read just where they should and I now have a vial of that Coyote urine under the switch to deter any more of those wascally wabbits. Thanks again for the replies. Gary KA1J --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Coax issues
Hi Gary! I'm surprised at wabbits chewing coax! Usually squirrels! Although I would hope the coyote urine would help in any case. The little tree rats can be really destructive! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Gary Smith Sent: Wednesday, February 19, 2014 2:05 PM To: Topband@contesting.com Subject: Re: Topband: Coax issues Resolution: Eat more rabbit. Thanks again for the pointer to the 259B being an answer. I now see it will do more than I knew, I didn't know about the advanced mode. So... Last night I disconnected the coax in to the distal coax switch, it was not connected in the shack but I read a dead short with the fluke. This morning I went out and disconnected the coax so I could make a reading on both ends of the coax to see how well they jived. Found the instigator of the problem that damned rabbit chewed mostly through the control cable to the coax switch. He must have bit into the voltage that stopped him. However, he had chewed through the cable and had severed 3-4 wires of the 6 involved in switching and this disconnected the coax from the antenna. I was trying for 3B9/OE4AAC on Rodriguez on 17 using the amp. Amazingly the amp didn't have any issue but that energy had to go somewhere. I reattached the control wires at the switch, went back to the shack and read 515 feet to fault and that multiplied by the VF of .66 = 334 feet. Not knowing the exact footage of the coax, I went to the distal end and remeasured from there and kept getting different distances but one thing was for sure, it was easier getting the zero readings at the shack end. I cut off the connector there still was a dead short in the coax so I cut away the roll of coax I used for a choke thinking it would be found there but no. I started the long grind of pulling up the coax from under the leaves snow came to something I'd forgotten about, I had run short of coax and needed to use a female/female jumper to add a length of coax to reach the switch box. I undid the sealant could smell the burn. The end going to the house was undamaged but the other end had fried at the connector. I'd forgotten that the last part was foam coax my long run used the hard plastic dielectric; it was the foam that melted shorted. All's well now with the coax and antennas, all read just where they should and I now have a vial of that Coyote urine under the switch to deter any more of those wascally wabbits. Thanks again for the replies. Gary KA1J --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Update from AG6X shunt feed project
Wow!, that's perfect, Carl!! That should result in better than 1.2:1 load VSWR!! No wonder you see a flat line at the transmitter end! Looks like either 90' or 67' would be good tap points, but 67' is better! Can't do much better than 42 ohms feed-point resistance! If you're seeing a flat line from 1800-1850 that's pretty good bandwidth!! I'm not sure how much you might gain by adding additional gamma wires, The loss in 67' of 14 ga wire can't be that great! The impedance of your gamma may decrease with the additional wires, requiring a larger capacitor to tune it! There's a lot to be said for If it ain't broke -don't fix lt! Regarding the gamma capacitor - if I did my quick back of the envelope 'rithmatic right, the 140 pf of capacitance should have about 36.2 ohms of capacitive reactance at 1.8 MHz. Now, if you are delivering 1500 watts of RF into a 42 ohm load, that's a little less than 6 amps RMS of RF current. That would result in an RMS voltage of about 220 volts across the 140 pF, or about 330 volts peak. So your 4500 volt Cardwell should have no problems dealing with it. No need to use your vacuum variable! If you add additional gamma wires, you may need something a bit larger than your 160 pF capacitor, but the voltage requirements wouldn't increase significantly, if at all. Of course whatever capacitor you use, you, of course, need to protect it from moisture, insects etc. Sounds like you have it working well, and you can concentrate on workin' on your radial field. Of course, as you improve the radials, you may see that 42 ohm resistance drop a little and your BW decrease as you reduce the ground losses and the Q of you antenna system increases! I've had that experience in the past. Anyway, Carl, sounds like you have it playing pretty well! Have fun! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carl Braun Sent: Saturday, February 15, 2014 9:03 PM To: topband@contesting.com Subject: Topband: Update from AG6X shunt feed project All I decided to take a chance at tapping the tower at 67' and apply some series capacitance to see how the structure would work there before tapping it at the 90' level. Here is what I found: The gamma arm spacing is at 33 and with 140pf in series I see 42+j0 ohms at the feedpoint. Inside the shack at the end of the LMR 400 I see basically FLAT SWR from 1800 to 1850 and 1.5:1 at 1865...with the cap fixed at 140pf. All of that with my skimpy (single 14AWG) gamma wire. Tomorrow I plan on dropping the tower again to add the additional 2 or 3 wires to create the gamma wire cage. My current PVC standoffs have been modified to accept three gamma wires spaced approx. 10 apart (though I'm only using one now as I said before). I'm assuming this MAY provide me with a couple more ohms getting me closer to the magical 50 but bandwidth is what I'm truly after. If I still need a few more ohms I may extend the gamma and standoff arms out another 6 or so...which would be the MAX reach without installing new arm and standoffs. So...with these low capacitance requirements (140pf now and possibly less with the multiple gamma wires) will I still need to scrounge my vacuum variable out of storage or will my 4500V Cardwell cap get the job done at 1500W? Thanks to all who offered their advice and look for an update from me after the gamma cage is assembled and additional radials are installed Carl AG6X _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Update from AG6X shunt feed project
FB, Carl! Well, if you're hearing well on that tall vertical, the noise environment must not be too bad in your area, It's pretty bad here in Raleigh, so I had to resort to terminated receiving loops for 160 - and they help on 80 also. Yes, I had the same thought about moving that tap point higher as you improve your radial field. After all, if that 68 ohms drops to 60 ohms that's still 1.2:1 VSWR, but the BW might be a little better. You might want to wait until AFTER you've done the radial improvements before adding the additional gamma wires and selecting the tuning capacitor. Sounds like your hard work is paying off! FB on the KH6s! I've worked a number of them from here in Raleigh, but that's a tougher path than CA-KH6! Keep at it! Sounds like it's coming together and playing well! Have a good day! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carl Braun Sent: Sunday, February 16, 2014 10:49 AM To: Charlie Cunningham Cc: topband@contesting.com Subject: Re: Topband: Update from AG6X shunt feed project Thanks Charlie I haven't transmitted on the antenna yet but I did hear KH6XX, KH6LC and WL7E this morning along with a bunch of stateside guys participating in the contest. N7GP and K7FA in AZ were +20 this morning and N7XM was loud too. I'm looking forward to seeing improvements with additional radials but I do anticipate the R dropping too. If things improve too much I may be moving the gamma arm up to the 90' level yet. More later. Thanks again Carl AG6X Sent from my iPhone On Feb 16, 2014, at 7:37 AM, Charlie Cunningham charlie-cunning...@nc.rr.com wrote: Wow!, that's perfect, Carl!! That should result in better than 1.2:1 load VSWR!! No wonder you see a flat line at the transmitter end! Looks like either 90' or 67' would be good tap points, but 67' is better! Can't do much better than 42 ohms feed-point resistance! If you're seeing a flat line from 1800-1850 that's pretty good bandwidth!! I'm not sure how much you might gain by adding additional gamma wires, The loss in 67' of 14 ga wire can't be that great! The impedance of your gamma may decrease with the additional wires, requiring a larger capacitor to tune it! There's a lot to be said for If it ain't broke -don't fix lt! Regarding the gamma capacitor - if I did my quick back of the envelope 'rithmatic right, the 140 pf of capacitance should have about 36.2 ohms of capacitive reactance at 1.8 MHz. Now, if you are delivering 1500 watts of RF into a 42 ohm load, that's a little less than 6 amps RMS of RF current. That would result in an RMS voltage of about 220 volts across the 140 pF, or about 330 volts peak. So your 4500 volt Cardwell should have no problems dealing with it. No need to use your vacuum variable! If you add additional gamma wires, you may need something a bit larger than your 160 pF capacitor, but the voltage requirements wouldn't increase significantly, if at all. Of course whatever capacitor you use, you, of course, need to protect it from moisture, insects etc. Sounds like you have it working well, and you can concentrate on workin' on your radial field. Of course, as you improve the radials, you may see that 42 ohm resistance drop a little and your BW decrease as you reduce the ground losses and the Q of you antenna system increases! I've had that experience in the past. Anyway, Carl, sounds like you have it playing pretty well! Have fun! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carl Braun Sent: Saturday, February 15, 2014 9:03 PM To: topband@contesting.com Subject: Topband: Update from AG6X shunt feed project All I decided to take a chance at tapping the tower at 67' and apply some series capacitance to see how the structure would work there before tapping it at the 90' level. Here is what I found: The gamma arm spacing is at 33 and with 140pf in series I see 42+j0 ohms at the feedpoint. Inside the shack at the end of the LMR 400 I see basically FLAT SWR from 1800 to 1850 and 1.5:1 at 1865...with the cap fixed at 140pf. All of that with my skimpy (single 14AWG) gamma wire. Tomorrow I plan on dropping the tower again to add the additional 2 or 3 wires to create the gamma wire cage. My current PVC standoffs have been modified to accept three gamma wires spaced approx. 10 apart (though I'm only using one now as I said before). I'm assuming this MAY provide me with a couple more ohms getting me closer to the magical 50 but bandwidth is what I'm truly after. If I still need a few more ohms I may extend the gamma and standoff arms out another 6 or so...which would be the MAX reach without installing new arm and standoffs. So...with these low capacitance requirements (140pf now and possibly less with the multiple gamma wires) will I still need to scrounge my vacuum
Re: Topband: Still in search of resonance - Detailed Observations and Calculations
Hi, Carl I did a bit of further investigation and work on your problem. I think you are done, as follows: 1.0 Just tap the Skyneedle at 90' and tune out the series inductive reactance with a variable capacitor, leaving you with 68 ohms real at the bottom of your drop wire. Great match! VSWR on 50 ohm feed cable of 1.4:1. 2.0 Now, let's assume you have 250 feet of Belden 8237 (RG-8) feeding the bottom of the drop wire. Losses are as follows: Top of Form Set Parameters as Desired Line Type: Line Length: Feet Meters Frequency: MHz Load SWR: : 1 Power In: W Bottom of Form Top of Form Results Matched Loss: dB SWR Loss: dB Total Loss: dB Power Out: W Bottom of Form Note that the excess loss due to the SWR on the cable is 0.029 dB, out of a total loss in 250 of RG-8 of 0.606 dB Note the flat-loss or matched loss of the cable (at 1:1 VSWR) is 0.577 dB. So theres no real point in struggling to get to exactly 50 ohms real at the bottom of your drop-wire to recover 0.029 dB of loss in 250 of cable! Your 68 ohms is just fine! Just match tle line at the transmitter end and accept the modest 1.4:1 VSWR at the load end. As you observed, when tapped at 90 the tower heard very well and you made some contacts with your FT-1000D barefoot. So, it surely appears that you have a very good, well-matched antenna when you tap at 90 and tune out the series inductance of the gamma match in the normal way using a series capacitor. Just tune for X=0 at th bottom of the drop wire, connect the feedline and match the feedline at the transmitter and enjoy!! Of course, with a tower that tall, you probably want a spark gap and/or a gas-tube at the feed-point and sopme sortof static bleed to defend agains static charge and lightning! GL! Have fun! 73. Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carl Braun Sent: Friday, February 14, 2014 6:15 PM To: '160' Subject: Topband: Still in search of resonance List Some of you may have followed my efforts in trying to shunt feed my 90' Tri-Ex Skyneedle with 20 meter yagi at 93'. I'm still unable to find any sort of resonance point on the tower. To refresh everyone's memory here are the specifics: 90' Skyneedle that is 12 round at the base and 4 round at the top 13' of mast out the top 5 element Telrex 20M monobander mounted at the 93' level. No other antennas on the tower 1 ½ copper pipe as a radial ring that surrounds the concrete base that measures 4' x 8' rectangle. Three 8' ground rods are connected to the radial ring via 1 copper strap that is .125 thick. Currently I have 27 14AWG insulated wire radials. Most of the radials are 20' to 50' long with three at 90 to 120' long and four of them connected to my 40M vertical array which have 100 count radials 50' to 100' each. The tower is grounded to each ground rod via 1 copper strap .125 thick and, as mentioned above, the ground rods are connected to the radial ring with the same strap with copper clad stainless screws. When I bolted the gamma arm to the tower at the 90' height I dropped a single 14AWG wire to the ground where my FLUKE meter read ZERO ohms between the radial ring and the end of the gamma wire with no fluctuations so I'm confident that I have good continuity throughout the tower. Here are the readings that I saw on the MFJ analyzer with the gamma arm mounted at the (4) points on the tower that are available... With the gamma arm mounted at 90' and 36 spacing I saw 425 ohms at the end of the drop wire on the MFJ With the gamma arm mounted at 67' and 36 spacing I saw 380 ohms at the end of the drop wire on the MFJ With the gamma arm mounted at 46' and 36 spacing I saw 240 ohms at the end of the drop wire on the MFJ With the gamma arm mounted at 28' and 36 spacing I saw 120 ohms at the end of the drop wire on the MFJ At all of these points I was able to knock down the R with my honkin' 1050pf cap to some resonance sort of resonance at 1.825 MHz but, as most everyone has indicated, I should be able to find a 50 ohm tap somewhere on the tower. I can't find it. When I had the gamma arm mounted at the 90' level. I was able to put my baby variable 160pf inline to bring the 425 ohm impedance down to about 60 ohms and the antenna heard very well; especially on the 1700 KHz broadcast band, with a 2.4:1 Vswr. Similar results could be seen at the other levels too as long as I brought the R down with a variable cap. Yesterday, with the gamma arm at the 46' level (and 240 ohms on the MFJ) I was able to put the big variable inline to bring the reading to 24 ohms with a TRUE X=0. With a 22 ohm to 50 ohm UNUN, I saw 1.3:1 Vswr on the output of the UNUN. I worked a W2 in NJ and a W4 in Florida with just the 1000D.
Re: Topband: Palomar R-X Noise Bridge
I'm a great believer in ferrite sleeve baluns, Carl! That's all that I use, and with a little work you can even connect two of them for 4:1 nalance. 73, Charlie, K4OTV -Original Message- From: Carl [mailto:k...@jeremy.mv.com] Sent: Saturday, February 15, 2014 11:05 AM To: Charlie Cunningham; 'TopBand' Subject: Re: Topband: Palomar R-X Noise Bridge The lowest loss cable I have here is 75 Ohm 1 General Cable Fused Disc; its under a differnt name these days. Mostly air with poly discs and used for the 200' runs for 10M, 2M, and 222 MHz. For the 160/80 inverted vee it is 450' of regular foamed 3/4 75 Ohm CATV hardline with a RG-11 jumper and plenty of ferrite to the feed point. Ive been using ferrite sleeve baluns since the mid 70's; I was introduced to them by the company I worked for who was building equipment for the joint CIA/DOD Tempest program. Carl KM1H - Original Message - From: Charlie Cunningham charlie-cunning...@nc.rr.com To: j...@audiosystemsgroup.com; 'TopBand' topband@contesting.com Sent: Friday, February 14, 2014 10:00 PM Subject: Re: Topband: Palomar R-X Noise Bridge All generally true, I expect, but I also believe that dielectric constant and dielectric losses also figure in and the lowest loss lines would be filled with air, dry nitrogen or evacuated. I expect those would likely be the lowest loss AND highest velocity factor cases. 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Jim Brown Sent: Friday, February 14, 2014 9:42 PM To: 'TopBand' Subject: Re: Topband: Palomar R-X Noise Bridge On 2/14/2014 2:17 PM, Carl wrote: Isnt that what lowest loss means? At least that was my intention. I must not have written clearly enough. I was not questioning the low loss, only that the high Vf was the way to get it. You DO get the low loss by going to larger coax, (like the 7/8-in hard line), but it's the fact that it's LARGER and has lower RF resistance, NOT the higher Vf. Think of it this way -- The higher Vf cable has less attenuation per ft because the higher Vf allows the center conductor to be larger. But a stub made with foam coax with Vf = 0.84 must be 27% longer than one with with a solid dielectric and Vf =.66. If those coaxes are the same diameter and of comparable quality, the stub attenuation and Q will be nearly the same. 73, Jim K9YC _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband - No virus found in this message. Checked by AVG - www.avg.com Version: 2014.0.4259 / Virus Database: 3705/7095 - Release Date: 02/15/14 _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Palomar R-X Noise Bridge
Do tell! -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of ZR Sent: Saturday, February 15, 2014 11:05 AM To: j...@audiosystemsgroup.com; 'TopBand' Subject: Re: Topband: Palomar R-X Noise Bridge - Original Message - From: Jim Brown j...@audiosystemsgroup.com To: 'TopBand' topband@contesting.com Sent: Saturday, February 15, 2014 12:15 AM Subject: Re: Topband: Palomar R-X Noise Bridge On 2/14/2014 7:00 PM, Charlie Cunningham wrote: All generally true, I expect, but I also believe that dielectric constant and dielectric losses also figure in and the lowest loss lines would be filled with air, dry nitrogen or evacuated. I expect those would likely be the lowest loss AND highest velocity factor cases. If you run the equations, you find that below about 1 GHz, the losses are all copper losses. Dielectric loss is a few percent of the total loss in the 500 MHz range. The benefit of a foam dielectric at HF and VHF is that it allows the center conductor to be larger for a given shield diameter. But the improvement in loss of a foam dielectric coax below 1 GHz is entirely due to the center conductor being larger. BTW -- the relevant equation is on each Times data sheet. 73, Jim K9YC Dielectric losses become evident at 2M with 1500W and at 432 400W of steady carrier will heat up even the best N connectors and RG-213. For that reason many are switching to the 7/16 DIN. Carl KM1H _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Still in search of resonance - Detailed Observations and Calculations
Sorry, Carl! My loss tables didn't translate from HTML to the reflector. I'll re-build the tables manually and re-send this message! Sorry! Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Charlie Cunningham Sent: Saturday, February 15, 2014 11:35 AM To: 'Carl Braun'; '160' Subject: Re: Topband: Still in search of resonance - Detailed Observations and Calculations Hi, Carl I did a bit of further investigation and work on your problem. I think you are done, as follows: 1.0 Just tap the Skyneedle at 90' and tune out the series inductive reactance with a variable capacitor, leaving you with 68 ohms real at the bottom of your drop wire. Great match! VSWR on 50 ohm feed cable of 1.4:1. 2.0 Now, let's assume you have 250 feet of Belden 8237 (RG-8) feeding the bottom of the drop wire. Losses are as follows: Top of Form Set Parameters as Desired Line Type: Line Length: Feet Meters Frequency: MHz Load SWR: : 1 Power In: W Bottom of Form Top of Form Results Matched Loss: dB SWR Loss: dB Total Loss: dB Power Out: W Bottom of Form Note that the excess loss due to the SWR on the cable is 0.029 dB, out of a total loss in 250 of RG-8 of 0.606 dB Note the flat-loss or matched loss of the cable (at 1:1 VSWR) is 0.577 dB. So theres no real point in struggling to get to exactly 50 ohms real at the bottom of your drop-wire to recover 0.029 dB of loss in 250 of cable! Your 68 ohms is just fine! Just match tle line at the transmitter end and accept the modest 1.4:1 VSWR at the load end. As you observed, when tapped at 90 the tower heard very well and you made some contacts with your FT-1000D barefoot. So, it surely appears that you have a very good, well-matched antenna when you tap at 90 and tune out the series inductance of the gamma match in the normal way using a series capacitor. Just tune for X=0 at th bottom of the drop wire, connect the feedline and match the feedline at the transmitter and enjoy!! Of course, with a tower that tall, you probably want a spark gap and/or a gas-tube at the feed-point and sopme sortof static bleed to defend agains static charge and lightning! GL! Have fun! 73. Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carl Braun Sent: Friday, February 14, 2014 6:15 PM To: '160' Subject: Topband: Still in search of resonance List Some of you may have followed my efforts in trying to shunt feed my 90' Tri-Ex Skyneedle with 20 meter yagi at 93'. I'm still unable to find any sort of resonance point on the tower. To refresh everyone's memory here are the specifics: 90' Skyneedle that is 12 round at the base and 4 round at the top 13' of mast out the top 5 element Telrex 20M monobander mounted at the 93' level. No other antennas on the tower 1 ½ copper pipe as a radial ring that surrounds the concrete base that measures 4' x 8' rectangle. Three 8' ground rods are connected to the radial ring via 1 copper strap that is .125 thick. Currently I have 27 14AWG insulated wire radials. Most of the radials are 20' to 50' long with three at 90 to 120' long and four of them connected to my 40M vertical array which have 100 count radials 50' to 100' each. The tower is grounded to each ground rod via 1 copper strap .125 thick and, as mentioned above, the ground rods are connected to the radial ring with the same strap with copper clad stainless screws. When I bolted the gamma arm to the tower at the 90' height I dropped a single 14AWG wire to the ground where my FLUKE meter read ZERO ohms between the radial ring and the end of the gamma wire with no fluctuations so I'm confident that I have good continuity throughout the tower. Here are the readings that I saw on the MFJ analyzer with the gamma arm mounted at the (4) points on the tower that are available... With the gamma arm mounted at 90' and 36 spacing I saw 425 ohms at the end of the drop wire on the MFJ With the gamma arm mounted at 67' and 36 spacing I saw 380 ohms at the end of the drop wire on the MFJ With the gamma arm mounted at 46' and 36 spacing I saw 240 ohms at the end of the drop wire on the MFJ With the gamma arm mounted at 28' and 36 spacing I saw 120 ohms at the end of the drop wire on the MFJ At all of these points I was able to knock down the R with my honkin' 1050pf cap to some resonance sort of resonance at 1.825 MHz but, as most everyone has indicated, I should be able to find a 50 ohm tap somewhere on the tower. I can't find it. When I had the gamma arm mounted at the 90' level. I was able to put my baby variable 160pf inline to bring the 425 ohm impedance down to about 60 ohms and the antenna heard very well; especially on the 1700 KHz broadcast band
Re: Topband: Still in search of resonance - Detailed Observations and Calculations
Hi, Jim Well, Maxwell's W2DU balu ns are ferrite sleeve baluns and you can get those that go down to 160m. It's a matter of choosine the right ferrite for the frequenc;y range of interest, and using enough ferrite to build p the common-mode impedance! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Charlie Cunningham Sent: Saturday, February 15, 2014 11:45 AM To: 'Carl Braun'; '160' Subject: Re: Topband: Still in search of resonance - Detailed Observations and Calculations Sorry, Carl! My loss tables didn't translate from HTML to the reflector. I'll re-build the tables manually and re-send this message! Sorry! Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Charlie Cunningham Sent: Saturday, February 15, 2014 11:35 AM To: 'Carl Braun'; '160' Subject: Re: Topband: Still in search of resonance - Detailed Observations and Calculations Hi, Carl I did a bit of further investigation and work on your problem. I think you are done, as follows: 1.0 Just tap the Skyneedle at 90' and tune out the series inductive reactance with a variable capacitor, leaving you with 68 ohms real at the bottom of your drop wire. Great match! VSWR on 50 ohm feed cable of 1.4:1. 2.0 Now, let's assume you have 250 feet of Belden 8237 (RG-8) feeding the bottom of the drop wire. Losses are as follows: Top of Form Set Parameters as Desired Line Type: Line Length: Feet Meters Frequency: MHz Load SWR: : 1 Power In: W Bottom of Form Top of Form Results Matched Loss: dB SWR Loss: dB Total Loss: dB Power Out: W Bottom of Form Note that the excess loss due to the SWR on the cable is 0.029 dB, out of a total loss in 250 of RG-8 of 0.606 dB Note the flat-loss or matched loss of the cable (at 1:1 VSWR) is 0.577 dB. So theres no real point in struggling to get to exactly 50 ohms real at the bottom of your drop-wire to recover 0.029 dB of loss in 250 of cable! Your 68 ohms is just fine! Just match tle line at the transmitter end and accept the modest 1.4:1 VSWR at the load end. As you observed, when tapped at 90 the tower heard very well and you made some contacts with your FT-1000D barefoot. So, it surely appears that you have a very good, well-matched antenna when you tap at 90 and tune out the series inductance of the gamma match in the normal way using a series capacitor. Just tune for X=0 at th bottom of the drop wire, connect the feedline and match the feedline at the transmitter and enjoy!! Of course, with a tower that tall, you probably want a spark gap and/or a gas-tube at the feed-point and sopme sortof static bleed to defend agains static charge and lightning! GL! Have fun! 73. Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carl Braun Sent: Friday, February 14, 2014 6:15 PM To: '160' Subject: Topband: Still in search of resonance List Some of you may have followed my efforts in trying to shunt feed my 90' Tri-Ex Skyneedle with 20 meter yagi at 93'. I'm still unable to find any sort of resonance point on the tower. To refresh everyone's memory here are the specifics: 90' Skyneedle that is 12 round at the base and 4 round at the top 13' of mast out the top 5 element Telrex 20M monobander mounted at the 93' level. No other antennas on the tower 1 ½ copper pipe as a radial ring that surrounds the concrete base that measures 4' x 8' rectangle. Three 8' ground rods are connected to the radial ring via 1 copper strap that is .125 thick. Currently I have 27 14AWG insulated wire radials. Most of the radials are 20' to 50' long with three at 90 to 120' long and four of them connected to my 40M vertical array which have 100 count radials 50' to 100' each. The tower is grounded to each ground rod via 1 copper strap .125 thick and, as mentioned above, the ground rods are connected to the radial ring with the same strap with copper clad stainless screws. When I bolted the gamma arm to the tower at the 90' height I dropped a single 14AWG wire to the ground where my FLUKE meter read ZERO ohms between the radial ring and the end of the gamma wire with no fluctuations so I'm confident that I have good continuity throughout the tower. Here are the readings that I saw on the MFJ analyzer with the gamma arm mounted at the (4) points on the tower that are available... With the gamma arm mounted at 90' and 36 spacing I saw 425 ohms at the end of the drop wire on the MFJ With the gamma arm mounted at 67' and 36 spacing I saw 380 ohms at the end of the drop wire on the MFJ With the gamma arm mounted at 46' and 36 spacing I saw 240 ohms at the end of the drop wire on the MFJ With the gamma arm mounted at 28' and 36
Re: Topband: Palomar R-X Noise Bridge
Hi, Jim Well, Maxwell's W2DU balu ns are ferrite sleeve baluns and you can get those that go down to 160m. It's a matter of choosine the right ferrite for the frequenc;y range of interest, and using enough ferrite to build p the common-mode impedance! 73, Charlie, K4OTV From: James Rodenkirch [mailto:rodenkirch_...@msn.com] Sent: Saturday, February 15, 2014 11:45 AM To: Charlie Cunningham; 'Carl'; Top Band Contesting Subject: RE: Topband: Palomar R-X Noise Bridge Carl: I've read, at several places, that sleeve baluns are effective at VHF and above but not at HF frequencies..thoughts?? 72/73, Jim Rodenkirch --- former Tempest inspector for the U.S. Navy..ah...Tempest comcerns - the good 'ol days hi Hi! From: charlie-cunning...@nc.rr.com To: k...@jeremy.mv.com; topband@contesting.com Date: Sat, 15 Feb 2014 11:39:14 -0500 Subject: Re: Topband: Palomar R-X Noise Bridge I'm a great believer in ferrite sleeve baluns, Carl! That's all that I use, and with a little work you can even connect two of them for 4:1 nalance. 73, Charlie, K4OTV -Original Message- From: Carl [mailto:k...@jeremy.mv.com] Sent: Saturday, February 15, 2014 11:05 AM To: Charlie Cunningham; 'TopBand' Subject: Re: Topband: Palomar R-X Noise Bridge The lowest loss cable I have here is 75 Ohm 1 General Cable Fused Disc; its under a differnt name these days. Mostly air with poly discs and used for the 200' runs for 10M, 2M, and 222 MHz. For the 160/80 inverted vee it is 450' of regular foamed 3/4 75 Ohm CATV hardline with a RG-11 jumper and plenty of ferrite to the feed point. Ive been using ferrite sleeve baluns since the mid 70's; I was introduced to them by the company I worked for who was building equipment for the joint CIA/DOD Tempest program. Carl KM1H - Original Message - From: Charlie Cunningham charlie-cunning...@nc.rr.com To: j...@audiosystemsgroup.com; 'TopBand' topband@contesting.com Sent: Friday, February 14, 2014 10:00 PM Subject: Re: Topband: Palomar R-X Noise Bridge All generally true, I expect, but I also believe that dielectric constant and dielectric losses also figure in and the lowest loss lines would be filled with air, dry nitrogen or evacuated. I expect those would likely be the lowest loss AND highest velocity factor cases. 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Jim Brown Sent: Friday, February 14, 2014 9:42 PM To: 'TopBand' Subject: Re: Topband: Palomar R-X Noise Bridge On 2/14/2014 2:17 PM, Carl wrote: Isnt that what lowest loss means? At least that was my intention. I must not have written clearly enough. I was not questioning the low loss, only that the high Vf was the way to get it. You DO get the low loss by going to larger coax, (like the 7/8-in hard line), but it's the fact that it's LARGER and has lower RF resistance, NOT the higher Vf. Think of it this way -- The higher Vf cable has less attenuation per ft because the higher Vf allows the center conductor to be larger. But a stub made with foam coax with Vf = 0.84 must be 27% longer than one with with a solid dielectric and Vf =.66. If those coaxes are the same diameter and of comparable quality, the stub attenuation and Q will be nearly the same. 73, Jim K9YC _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband - No virus found in this message. Checked by AVG - www.avg.com Version: 2014.0.4259 / Virus Database: 3705/7095 - Release Date: 02/15/14 _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: FW: Still in search of resonance - Detailed Observations and Calculations
Well, here it is with the re-built loss table, Carl 73, Charlie, K4OTV From: Charlie Cunningham [mailto:charlie-cunning...@nc.rr.com] Sent: Saturday, February 15, 2014 11:35 AM To: 'Carl Braun'; '160' Subject: RE: Topband: Still in search of resonance - Detailed Observations and Calculations Hi, Carl I did a bit of further investigation and work on your problem. I think you are done, as follows: 1.0 Just tap the Skyneedle at 90' and tune out the series inductive reactance with a variable capacitor, leaving you with 68 ohms real at the bottom of your drop wire. Great match! VSWR on 50 ohm feed cable of 1.4:1. 2.0 Now, let's assume you have 250 feet of Belden 8237 (RG-8) feeding the bottom of the drop wire. Losses are as follows: Line/Load Line type:Belden 8237 RG8 Line length 250 Frequency 1.8 MHz Load SWR1.4:1 Power In 100W Results: Matched Loss: 0.577 dB SWR Loss 0.029 dB Total Loss0.606 dB Power Out 86.982 W Note that the excess loss due to the SWR on the cable is 0.029 dB, out of a total loss in 250 of RG-8 of 0.606 dB Note the flat-loss or matched loss of the cable (at 1:1 VSWR) is 0.577 dB. So theres no real point in struggling to get to exactly 50 ohms real at the bottom of your drop-wire to recover 0.029 dB of loss in 250 of cable! Your 68 ohms is just fine! Just match tle line at the transmitter end and accept the modest 1.4:1 VSWR at the load end. As you observed, when tapped at 90 the tower heard very well and you made some contacts with your FT-1000D barefoot. So, it surely appears that you have a very good, well-matched antenna when you tap at 90 and tune out the series inductance of the gamma match in the normal way using a series capacitor. Just tune for X=0 at th bottom of the drop wire, connect the feedline and match the feedline at the transmitter and enjoy!! Of course, with a tower that tall, you probably want a spark gap and/or a gas-tube at the feed-point and sopme sortof static bleed to defend agains static charge and lightning! GL! Have fun! 73. Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carl Braun Sent: Friday, February 14, 2014 6:15 PM To: '160' Subject: Topband: Still in search of resonance List Some of you may have followed my efforts in trying to shunt feed my 90' Tri-Ex Skyneedle with 20 meter yagi at 93'. I'm still unable to find any sort of resonance point on the tower. To refresh everyone's memory here are the specifics: 90' Skyneedle that is 12 round at the base and 4 round at the top 13' of mast out the top 5 element Telrex 20M monobander mounted at the 93' level. No other antennas on the tower 1 ½ copper pipe as a radial ring that surrounds the concrete base that measures 4' x 8' rectangle. Three 8' ground rods are connected to the radial ring via 1 copper strap that is .125 thick. Currently I have 27 14AWG insulated wire radials. Most of the radials are 20' to 50' long with three at 90 to 120' long and four of them connected to my 40M vertical array which have 100 count radials 50' to 100' each. The tower is grounded to each ground rod via 1 copper strap .125 thick and, as mentioned above, the ground rods are connected to the radial ring with the same strap with copper clad stainless screws. When I bolted the gamma arm to the tower at the 90' height I dropped a single 14AWG wire to the ground where my FLUKE meter read ZERO ohms between the radial ring and the end of the gamma wire with no fluctuations so I'm confident that I have good continuity throughout the tower. Here are the readings that I saw on the MFJ analyzer with the gamma arm mounted at the (4) points on the tower that are available... With the gamma arm mounted at 90' and 36 spacing I saw 425 ohms at the end of the drop wire on the MFJ With the gamma arm mounted at 67' and 36 spacing I saw 380 ohms at the end of the drop wire on the MFJ With the gamma arm mounted at 46' and 36 spacing I saw 240 ohms at the end of the drop wire on the MFJ With the gamma arm mounted at 28' and 36 spacing I saw 120 ohms at the end of the drop wire on the MFJ At all of these points I was able to knock down the R with my honkin' 1050pf cap to some resonance sort of resonance at 1.825 MHz but, as most everyone has indicated, I should be able to find a 50 ohm tap somewhere on the tower. I can't find it. When I had the gamma arm mounted at the 90' level. I was able to put my baby variable 160pf inline to bring the 425 ohm impedance down to about 60 ohms and the antenna heard very well
Re: Topband: Still in search of resonance - Detailed Observations and Calculations
Thanks, Carl! Well, if you' heard a RX peak at 1770 KHz, it seems that you are awfully close! Just needs a little careful tweaking I would think. (I ass'ume that you are probably shootinf for something around 1830 KHz. BTW - the higher you tap on the tower, the smaller the series capacitor needs to be, since the increasing series inductive reactance will require increasing capacitive reactance (lower C) to cancel it, so it sounds like you can use the 160 pF capacitor for your series tuning C. I haven't used my MFJ 259 in a while, so I would need to get it out and review its operation but when you tuned down to 68 ohms impedance whtn tapped at 90', I expect that's where the impedance became pure real at 68 ohms. As an additional check you can drive the gamma wire with a little power from your TX or the MFJ and tune the series capacitor for minimum SWR. Sounds like it should come in around 1.4. If it does, you're done. Just bolt everything down and enjoy. Clearly, if the 46' tap pointis showing24 ohms real that's way too low on the tower for your tap point! It sound like90]isprobably the point you want! GL, Carl! Have fun! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carl Braun Sent: Saturday, February 15, 2014 3:11 PM To: Charlie Cunningham Cc: topband@contesting.com Subject: Re: Topband: Still in search of resonance - Detailed Observations and Calculations Charlie Thank you for your work and insight. It appears I've I may have provided some incorrect info. When I tapped the tower at 90' I used the 160pf variable cap to get down to the 68 ohm impedance measurement and, yes, it heard well with what appeared to be a peak at approx 1770kc I never transmitted there. I've only transmitted with the system when I had a tap at 46' where I saw 24 ohms and X=0 with the variable. Ap on series. Then I installed a 22 to 50 ohm Unun and made the contacts to east coast stations. I believe I have plenty of capacitance on hand if I tap the tower at 90' but given the 68 ohm reading at 90' with the variable cap and the 24 ohm reading at 46' with the variable cap don't you think the best bet would be my 67' tap point? Even if it's still a bit low in resistance at that point i could add a bit of parallel C in conjunction with the series C to bring the antenna to 50 ohms+j0? Please advise and thank you for the most enjoyable technical conversation. Carl AG6X Sent from my iPhone On Feb 15, 2014, at 9:14 AM, Charlie Cunningham charlie-cunning...@nc.rr.commailto:charlie-cunning...@nc.rr.com wrote: Well, here it is with the re-built loss table, Carl 73, Charlie, K4OTV From: Charlie Cunningham [mailto:charlie-cunning...@nc.rr.com] Sent: Saturday, February 15, 2014 11:35 AM To: 'Carl Braun'; '160' Subject: RE: Topband: Still in search of resonance - Detailed Observations and Calculations Hi, Carl I did a bit of further investigation and work on your problem. I think you are done, as follows: 1.0 Just tap the Skyneedle at 90' and tune out the series inductive reactance with a variable capacitor, leaving you with 68 ohms real at the bottom of your drop wire. Great match! VSWR on 50 ohm feed cable of 1.4:1. 2.0 Now, let's assume you have 250 feet of Belden 8237 (RG-8) feeding the bottom of the drop wire. Losses are as follows: Line/Load Line type:Belden 8237 RG8 Line length 250 Frequency 1.8 MHz Load SWR1.4:1 Power In 100W Results: Matched Loss: 0.577 dB SWR Loss 0.029 dB Total Loss0.606 dB Power Out 86.982 W Note that the excess loss due to the SWR on the cable is 0.029 dB, out of a total loss in 250 of RG-8 of 0.606 dB Note the flat-loss or matched loss of the cable (at 1:1 VSWR) is 0.577 dB. So theres no real point in struggling to get to exactly 50 ohms real at the bottom of your drop-wire to recover 0.029 dB of loss in 250 of cable! Your 68 ohms is just fine! Just match tle line at the transmitter end and accept the modest 1.4:1 VSWR at the load end. As you observed, when tapped at 90 the tower heard very well and you made some contacts with your FT-1000D barefoot. So, it surely appears that you have a very good, well-matched antenna when you tap at 90 and tune out the series inductance of the gamma match in the normal way using a series capacitor. Just tune for X=0 at th bottom of the drop wire, connect the feedline and match the feedline at the transmitter and enjoy!! Of course, with a tower that tall, you probably want a spark gap and/or a gas-tube at the feed-point and sopme sortof static bleed to defend agains static charge and lightning! GL! Have fun! 73. Charlie, K4OTV
Re: Topband: Still in search of resonance
Hee! -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carl Braun Sent: Saturday, February 15, 2014 3:53 PM To: Tom W8JI; '160' Subject: Re: Topband: Still in search of resonance Tom After reading your post yesterday I had a dream that I woke up and saw one of those flying monkeys on top of my tower laughing and sawing away. Carl AG6X -Original Message- From: Tom W8JI [mailto:w...@w8ji.com] Sent: Friday, February 14, 2014 6:02 PM To: Carl Braun; '160' Subject: Re: Topband: Still in search of resonance Hi Carl, It sounds like you are trying to find 50 ohms on the tower without any series capacitor by looking at R and X. I would not try to do that. The reactance puts you out of range on the MFJ bridge. You are down to a few bits difference between data points the PIC needs in the MFJ. Look at this below. You said: seen at the other levels too as long as I brought the R down with a variable cap. Yesterday, with the gamma arm at the 46' level (and 240 ohms on the MFJ) I was able to put the big variable inline to bring the reading to 24 ohms with a TRUE X=0. With a 22 ohm to 50 ohm UNUN, I saw 1.3:1 Vswr on the output of the UNUN. I worked a W2 in NJ and a W4 in Florida with just the 1000D. BUT...again...I'm bringing the R down with the capacitor...not finding 50 ohms anywhere on the tower Stop trying to find 50 ohms without the capacitor! Right now at 46 ft you were at 24 ohms with the capacitor. That should tell you and everyone on this reflector :-) that you are tapped too low now! Let's look at this in simple terms. Here is what you said: When I had the gamma arm mounted at the 90' level. I was able to put my baby variable 160pf inline to bring the 425 ohm impedance down to about 60 ohms and the antenna heard very well; especially on the 1700 KHz broadcast band, with a 2.4:1 Vswr. Similar results could be seen at the other levels too as long as I brought the R down with a variable cap. That is NORMAL. You will always need the capacitor. Always. The only way to eliminate the capacitor is to saw your Yagi antenna off the tower so the tower moves above 2 MHz. Then you will probably find a 50j0 tap without any capacitor. You also might use a large skirt, but why?? Just use a capacitor!!! If you are trying to eliminate the capacitor, you will have a lot of work to do. 73 Tom _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Folded dipole vs gamma match
All true, but I don't thnk Carl needs to shorten his tower or remove the yagi! I'd just use a series tuning capacitor! :-) Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Tom W8JI Sent: Saturday, February 15, 2014 4:07 PM To: Topband Subject: Topband: Folded dipole vs gamma match The step up ratio of a folded dipole occurs because the fed conductor extends parallel to the un-fed conductor for the entire length of the antenna. The element or element halves form 1/4 wave shorted stubs in differential excitation mode, but the current divides by ratios of effective diameters. The feedline, in effect, just samples a portion of the total current causing radiation. With a shunt feed system, the mechanism is different. The shorted stub formed by the gamma section is not 1/4 wave long, and parallels the feedpoint. Also, the gamma does not parallel the antenna length. There is actually not much change in the real part of impedance as the gamma rod changes ratio compared to element size. The slightly larger change is in reactance. For example, a 3 diameter gamma rod on a 1 inch diameter resonant 160 meter element at 40 feet produces an impedance of 289.6 + J 57.92 ohms Changing it to 0.1 inches results in 454.7 + J 130.7 ohms 130.7/57.92 = 2.26 ratio in reactance for a diameter ratio change of 30:1. 454.7/289.6 = 1.57 resistance ratio for the 30:1 change If I adjust the tap point to a good match (at 14 feet above ground) I have: 3 inch diameter gamma conductor 32.68 + J 65.45 ohms 0.1 inch gamma diameter 52.04 + J 111 ohms 1.6 ratio in resistance and 1.7 in reactance for a 30:1 change in rod diameter. The primary benefit in a larger diameter gamma rod is lower Q and lower voltage across the tuning capacitor. If I shorten the element, I can gamma match without a capacitor. 73 Tom _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Palomar R-X Noise Bridge
Walt surely did know his stuff and he published some great material!! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Tom W8JI Sent: Saturday, February 15, 2014 4:31 PM To: Top Band Contesting Subject: Re: Topband: Palomar R-X Noise Bridge Maxwell sort of stumbled on it in later years with those tiny beads that seriously overheated with most amps. We started with the type that fit over RG-213 and went from there to custom made, the big donuts, and sheet products from pioneers such as Arnold. Walt Maxwell was not only a real nice guy, he knew his stuff. Walt was a senior antenna design engineer for RCA, including satellite antennas. It is outrageous to say Walt Maxwell sort of stumbled on something so simple, and that heating of beads relates to amplifiers. The heating is much more an issue of abnormal common mode impedances, rather than power levels. Walt's article, along with articles by Lewallen, accelerated use of common mode chokes and current baluns. They got us away from those silly voltage baluns people were using. People who don't understand how things work are the people who spend a lifetime sort of stumbling on things. Why, I remember when Walt patiently taught me how conductor losses dominated transmission line loss, and why that was important! :-) 73 Tom _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Question - optimum number of radials
That's a lot of good information, Richard! Thanks for sharing! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Richard Fry Sent: Friday, February 14, 2014 7:00 AM To: topband@contesting.com Subject: Re: Topband: Question - optimum number of radials The r-f loss at the operating frequency in a set of buried radials varies with the conductivity and permittivity of the earth in which they are buried. The NEC4.2 study below shows that for poor earth conditions (within about 1/2WL from the base of the monopole), the number and length of buried radials needed to maintain an r-f loss of a few ohms in the ground return rises from that needed for more conductive earth. In the case of AM broadcast stations, the use of 120 buried radials each 1/4-wavelength (in free space) produces a ground system loss of 2 ohms or less. This is true no matter what are the characteristics of the the earth in which those 120 radials are buried. For a 1/4-wave, unloaded monopole with 35 ohms of radiation resistance and 2 ohms of ground system loss, antenna system radiation efficiency is 35/37 = 95% of the applied power (approx). The FCC requires that a minimum inverse distance groundwave field of 241 mV/m is produced by an applied power of 1 kW at at a distance of 1 km by even the lowest class of AM station (Class C). A perfect 1/4-wave monopole driven against a perfect ground plane produces about 313 mV/m for those conditions. A typical installation using an unloaded 1/4-wave monopole driven against 120 x 1/4-wave buried radials produces about 306 mV/m for those conditions -- which field is consistent with a monopole system with a radiation efficiency of 95%. The 241 mV/m minimum field required for Class C AM stations could be produced by a 1/4-wave monopole+ground system with about 59% efficiency. Class A AM stations such as WLW, WJR, WGN etc are required to generate an inverse distance groundwave field of 362 mV/m at 1 km for 1 kW of applied power. This cannot be done with a 1/4-wave monopole. Most of the Class A stations use monopole heights ranging from 180 to 195 degrees. WJR, Detroit uses a 195-deg monopole system that produces about 403 mV/m at 1 km for 1 kW of applied power. At their licensed transmitter power of 50 kW, that field becomes 403 x SQRT(50) = 2.85 V/m, approx. http://i62.photobucket.com/albums/h85/rfry-100/10m_Vert32Buried_Radials.jpg RF _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Question - optimum number of radials
Hi, Bill Well, like you, I also live on a fairly small city lot with way too much bedrock coming up to the surface and a long concrete driveway, so buried radials just aren't feasible for me! So I hung my inverted L in a tall tulip poplar in one corner of the lot and I ran two elevated resonant radials down the fence lines - elevated about 5-6 feet. I worked good stuff all over the world including JA and Indian Ocean, and VK6. If I could hear 'em, I could work 'em! BEST thing I EVER did for myself was to build a KAZ terminated receiving loop for the low-bands 160-30m, so I could HEAR more! Worked great!! And no, I didn't have 100 buried radials, but just a few elevated resonant radials will produce very effective results for the transmit antenna! 73 Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Bill Cromwell Sent: Friday, February 14, 2014 10:02 AM To: topband@contesting.com Subject: Re: Topband: Question - optimum number of radials On 02/14/2014 09:15 AM, Charlie Cunningham wrote: That's a lot of good information, Richard! Thanks for sharing! 73, Charlie, K4OTV The whole topic of radials as it applies to me on my small lot is put in as many as you can. The same probably applies to others on small lots. On top band I do not have room in *any* direction for a quarter wavelength radial..not even one. In some directions a quarter wavelength radial wire might be bent to fit but that begins the many compromises. Obviously that setup would have the antenna in one corner of the lot so there would be no radials at all in one or two directions. So.. no quarter wave radials at all. I have been buying small spools of wire and will be adding them to whatever puny little radial field I DO have. As soon as the ice and snow is gone (maybe in June?) I will be elevating my wire antenna the rest of the way to the treetops and adding in the radial wires. In the process of elevating the antenna I will learn to be ace with a rod n reel grin. The whole point of that exercise is to *miss* the tree and go over the top. So far I've only ever tried to *hit* a spot out on the water. It's not hard to hit the water wink. I didn't do too badly finding a particular spot on the water with the bait. But the tree top is not over there. It's up there. 73, Bill KU8H _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Question - optimum number of radials
Yeah, just a few elevated resonant radials can work wonders as you have discovered, Carl! And rock does get in the way of buried radials!! The models teach that elevated resonant radials should work very well! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carl Sent: Friday, February 14, 2014 10:46 AM To: Tom W8JI Cc: topband@contesting.com Subject: Re: Topband: Question - optimum number of radials While Tom touched on the subject yesterday the subject of an individuals ground conductivity has to be stressed, continuously it seems. The FCC maps arent perfect and hams usually dont have the options of perfect siting for their verticals as do many of the BC stations. Home developers often remove all of the good topsoil and sell it. They back fill with rocky sand and whatever else is cheap or worthless and finish with a skimcoat of real topsoil just thick enough to grow grass. My own attempt with 60-65 quarter wave radials 30 years ago at another home were dismal since the ground was pure sand left behind by the glaciers with a fresh water table about 4' down. Great for mixing concrete and drainage only. After I installed a 2X4 fence mesh around the base and out 50' could I reliably work DX. Going to elevated radials here on a granite hill in the same town saved a lot of work and works very well. Carl KM1H _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Palomar R-X Noise Bridge
I would expect it to work OK with 75 ohm cable. An open-circuited 1/4 wave line looks like a short at its sending end and you would be looking for a null as the line reaches a 1/4 wavelength, so I would expect the method to work fine with 75 ohm line. In fact, the 50 or 75 ohm line, if we consider it to be lossless would be operating at infinite VSWR so I wouldn't think the modest difference in characteristic impedance would make any real difference. 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of map...@windstream.net Sent: Friday, February 14, 2014 12:18 AM To: topband@contesting.com Subject: Topband: Palomar R-X Noise Bridge I have a question about using the noise bridge. I have used it cut stubs to 1/4 wavelength using 52 ohm cable with no problems. I now need some stubs using 75 ohm cable which I have on hand. Will the same procedure work for 75 ohm that works for 52 ohm cable, or will the different impedance need to be accounted for. I started to cut cable and this question came to me. My first thought is that it will work fine, but I am not sure. I did some searches on the web but found nothing about it. Any help would be appreciated. Thanks, Pat Armstrong KF5YZ _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Palomar R-X Noise Bridge
Makes sense. The lower the return-loss, the deeper the null! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Jim Brown Sent: Friday, February 14, 2014 4:17 PM To: topband@contesting.com Subject: Re: Topband: Palomar R-X Noise Bridge On 2/14/2014 10:55 AM, Carl wrote: The highest VF and lowest loss produces the deepest null but also the least deep null bandwidth due to the higher Q. Not always -- stubs made with higher Vf cables are longer, so in my experience they come out about the same for attenuation and bandwidth. The only way to get a deeper null (with the reduction in bandwidth you have noted), is to reduce the RF resistance -- this means larger diameter coax and a more robust shield, like hard line. 73, Jim K9YC _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Still in search of resonance
There seems to be some confusion, Carl! First of all, since the gamma match (regardless of the diameter of the gamma rod) is a shorted transmission line, less than 1/4 wavelength it WILL have series inductive reactance that you will need to tune out with a series variable capacitance. Second, I don't understand the R readings that you are reporting at various tap points with the MFJ, that come down when you apply the series C. That suggests to me that what you are reporting as R is R+jX or [R+jX], and it's coming down as you tune out the series reactance jX. If you find a tap point that results in 50 ohms real when you use the series-C to make X=0, that IS the 50 ohm tap point that you are looking for. You will NOT find a point that gives you 50 ohms real without the series C to tune out the inductive reactance, Other opinions notwithstanding, you CAN do the gamma match with 14 ga. wire, The only effect of using a thin gamma rod or gamma wire is to increase the losses a bit in the gamma, and to increase the inductance per unit length of the gamma. Finally, take care. That you don't have enough broadcast signal on the Sky needle to screw up the MFJ readings. ON additional note: In some cases guys use a shorter gamma that resultsn in a resistive real part LESS than 50 ohms. In this case only a portion of the series inductance is cancelled with the series C and theremainin inductive reactance is used in conjunction with a shunt variable C to form an L-network to match the real part UP to 50 ohms! Sounds like you are hitting all around it, Carl. Just remember that what you are searching for is R=50, and X=0, or R+jX = 50 + j0. GL! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carl Braun Sent: Friday, February 14, 2014 6:15 PM To: '160' Subject: Topband: Still in search of resonance List Some of you may have followed my efforts in trying to shunt feed my 90' Tri-Ex Skyneedle with 20 meter yagi at 93'. I'm still unable to find any sort of resonance point on the tower. To refresh everyone's memory here are the specifics: 90' Skyneedle that is 12 round at the base and 4 round at the top 13' of mast out the top 5 element Telrex 20M monobander mounted at the 93' level. No other antennas on the tower 1 ½ copper pipe as a radial ring that surrounds the concrete base that measures 4' x 8' rectangle. Three 8' ground rods are connected to the radial ring via 1 copper strap that is .125 thick. Currently I have 27 14AWG insulated wire radials. Most of the radials are 20' to 50' long with three at 90 to 120' long and four of them connected to my 40M vertical array which have 100 count radials 50' to 100' each. The tower is grounded to each ground rod via 1 copper strap .125 thick and, as mentioned above, the ground rods are connected to the radial ring with the same strap with copper clad stainless screws. When I bolted the gamma arm to the tower at the 90' height I dropped a single 14AWG wire to the ground where my FLUKE meter read ZERO ohms between the radial ring and the end of the gamma wire with no fluctuations so I'm confident that I have good continuity throughout the tower. Here are the readings that I saw on the MFJ analyzer with the gamma arm mounted at the (4) points on the tower that are available... With the gamma arm mounted at 90' and 36 spacing I saw 425 ohms at the end of the drop wire on the MFJ With the gamma arm mounted at 67' and 36 spacing I saw 380 ohms at the end of the drop wire on the MFJ With the gamma arm mounted at 46' and 36 spacing I saw 240 ohms at the end of the drop wire on the MFJ With the gamma arm mounted at 28' and 36 spacing I saw 120 ohms at the end of the drop wire on the MFJ At all of these points I was able to knock down the R with my honkin' 1050pf cap to some resonance sort of resonance at 1.825 MHz but, as most everyone has indicated, I should be able to find a 50 ohm tap somewhere on the tower. I can't find it. When I had the gamma arm mounted at the 90' level. I was able to put my baby variable 160pf inline to bring the 425 ohm impedance down to about 60 ohms and the antenna heard very well; especially on the 1700 KHz broadcast band, with a 2.4:1 Vswr. Similar results could be seen at the other levels too as long as I brought the R down with a variable cap. Yesterday, with the gamma arm at the 46' level (and 240 ohms on the MFJ) I was able to put the big variable inline to bring the reading to 24 ohms with a TRUE X=0. With a 22 ohm to 50 ohm UNUN, I saw 1.3:1 Vswr on the output of the UNUN. I worked a W2 in NJ and a W4 in Florida with just the 1000D. BUT...again...I'm bringing the R down with the capacitor...not finding 50 ohms anywhere on the tower. Is my radial field so poor that I'm seeing these goofy readings? Is the single 14AWG too thin causing goofy readings? I'm back to scratching my head. Comments from the list? Carl AG6X _ Topband
