Re: Topband: Series LC to notch AM broadcast ?
Hello Jim, Better, I think, is this notch, found at the IRCA Reprints: <https://www.ircaonline.org/editor_upload/File/reprints/irca-reprint-index.pdf>https://www.ircaonline.org/editor_upload/File/reprints/irca-reprint-index.pdf Look for Reprint A-063, An RF Notch Filter by VE6JY. You really should only need to notch the carrier of the offending AM station, as that's where the bulk of the overload will be coming from. It's a pretty amazing device, in my estimation. 73 Nick VE7DXR At 17:41 2022-02-20, jim.thom jim.t...@telus.net wrote: Has anybody tried using a simple series L-C to notch out ONE offending AM broadcast station ? I'm talking about wiring from hot side of coax...to chassis / groundlike via a T connector etc. On paper, it should work. Did some minor research, and one comment was that by using higher values of L would result in higher Q..and a deeper notch. Another comment stated to use some initial values, like what spits out on a L-C online calculator for practical values. then multiply one value by the other...then take the square root of the result. Then you ended up with 2 x numerically equal values of L + C. and supposedly the greatest notch depth. On software, I tried several values..from one extreme to the other, and they all resonate on the same freq. Also tried in software, using 2 x numerically same values..and it too, also resonates on the same freq. The rationale behind all of this is... in some cases, there is only one offending AM broadcast station. Typ HP filters offer little rejection towards the top end of the AM broadcast band. like 1200-1710 khz. I would like to try it, but am still confused as to which combo (using practical values) will result in the deepest notch. It would have to be wide enough to remove the 20 khz wide AM signal. A fixed coil + variable cap, or padded variable cap could be used to fine tune the notch freq. Perhaps 2 or more LC filters could be used in parallel, to notch out 2 or more offending stations ? Jim VE7RF _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector Nick Hall-Patch Victoria, BC Canada _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Preamp Placement?
Haven't seen much in the way of public replies to this, so hope that you've got some private ones. For a small mag loop, I'd use the preamp at the loop, especially if your feed line is coax. 73 Nick VE7DXR At 15:09 2022-01-16, Chris Maness wrote: Do preamps need to be close to electrically small mag loops to maximize SNR from common mode RFI? I would imagine in theory yes, but in application I have no experience to draw from. Thanks, Chris KQ6UP _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector Nick Hall-Patch Victoria, BC Canada _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: 1610 KHz AM Channel in USA
You might also check: https://www.ircaonline.org/editor_upload/File/TIS_2020.pdf IRCA is a MW DXers' club with a number of people who actively try to receive these flea power stations. 73 Nick VE7DXR At 20:43 2020-07-05, donov...@starpower.net wrote: Hi Hank, You can search for licensed TIS stations by state and frequency here, but just because they're licensed doesn't mean they're on the air... www.fcc.gov/media/radio/travelers-information-stations-search Callsign: WXK790 Licensee: PHOENIX, CITY OF Radio Service: Public Safety Pool, Conventional (PW) City: PHOENIX, AZ Status: Active Grant Date: 09/09/2014 Expiration: 12/06/2024 Site: 1 Address: 3400 E SKY HARBOR BLVD City: PHOENIX, AZ County: MARICOPA Coordinates: 33° 26' 7.2" N, 112° 0' 30.5" W Frequency: 1.610 0 73 Frank W3LPL On Sun, Jul 5, 2020, 3:16 PM HP wrote: > Where is the place to see active 1610 stations - I used to hear the one > for Sky Harbour A/P > here in Phoenix - but no more -hope not just further evidence of > incredible increase in noise > in last 5 years or so. > > Hank K7HP > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector Nick Hall-Patch Victoria, BC Canada _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Anyone with experience using CAT6 as feed line.
http://durenberger.com/wp-content/uploads/2019/11/BEVERAGE-ANTENNAS-IN-THE-DESERT.pptx presented at an International Radio Club of America conference a couple of years ago used a Cat-5 antenna as both a Beverage and as feed line from the far end. However, twisted pair lying on conductive ground has apparently quite high loss, per correspondence with KD9SV a couple of years ago: Twisted pair does work for an "above ground beverage" but does NOT work at all for a "Beverage on the ground" . http://www.iv3prk.it/new-page.htm says: My previous experiences in Italy with reversed Beverages using twisted pairs from CAT5 cable and later with RG58 coax on the ground were both negative. These comments don't sound promising so far as using twisted pair in a BOG unfortunately. Anyone with different experience? 73 Nick VE7DXR At 20:19 2020-05-17, Mikek wrote: Did a first test on a BOG, I noted it didn't have a f/b ratio. Then I noted I connected the wrong pair to the radio. That means the twisted pair is picking up signal. I terminated it hoping that would quiet it, It didn't. I corrected the wiring error, But the feed line pickup makes the BOG useless. On a previous BOG I used #18 twisted speaker wire and it picked up very little RF when connected the the radio. Do I need to do anything with the unused pairs, that would help? Any thoughts on how to prevent RF pickup by the feed line? Nick Hall-Patch Victoria, BC Canada _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Loop on the ground as a counterpoise
Your "loop ground" made me recall the US military "surface wire ground", Chris, which was (is?) used for mobile applications, and is often configured as a loop of wire, held down by metallic stakes, around a vehicle. Upon looking more closely, https://apps.dtic.mil/dtic/tr/fulltext/u2/a277285.pdf seems to be much more concerned with its utility as safety grounding, especially concerning lightning, so I don't know if any research was done concerning its effectiveness as a signal reception ground. I have used something like the "surface wire ground" on our coastal rocky "soil" (very resistant to ground rods) when using Beverage antennas. It seemed to work fine for matching transformer use, but not much use for termination ground. To be fair, ground rods don't particularly work here either for termination grounding. 73 Nick VE7DXR At 08:57 2020-05-04, Chris Moulding wrote: I've developed a High Z Antenna Amplifier for 160m and other HF use as previously mentioned on the list. Usually these would be used with a ground rod and 5m vertical element. With the lockdown it's not possible to nip to the shops for a ground rod so I looked at supplying a 10m wire as a counterpoise. At home and the workshop I have Loop on the Ground antennas from previous antenna experiments so I also tried using these with both ends of the loop connected to the amplifier ground terminal. On testing this gave significantly better signal to noise ratios than using a ground rod or a single wire counterpoise. Checking with a SDR receiver I could see that the usual local VDSL internet hash had disappeared. Both loops on the ground are 3m or 10' square. I've also tried it using a G7FEK vertical antenna at home with two 3m or 10' square loops on the ground with similar results seeing much reduced local noise compared with the ground radials I had before. Topband Dx might be a possibility for me now. I've never seen this mentioned in ham magazines before and I can't find anything with an internet search. Usually I find that all my good ideas have already been thought of 50 years ago. I suspect that the RF voltage in the loop counterpoise is much reduced over the voltage at the end of a radial wire reducing noise pickup in the radial system. I would like to model the loop on the ground counterpoise in a modelling tool. I use 4NEC2 but only have access to NEC2 so wires on the ground don't model correctly. Is there any one out there with access to suitable software that could model it for me? 73, Chris G4HYG _____ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector Nick Hall-Patch Victoria, BC Canada _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Ap progression graph from swpc.noaa.gov
Thanks Carl and Steve. Useful suggestions there, if they really have dumped the graph of monthly Ap. Nick At 20:00 2020-04-18, Carl Luetzelschwab wrote: Nick VE7DXR, At least they corrected the vertical axis of the 10.7 cm solar flux plot - it used to say sunspot number. What I do for the Ap is download the data from "Table of Recent Solar Indices (Preliminary) of Observed Monthly Mean Values" in the Data tab below the plots and import the data into Excel. Carl K9LA On Sat, Apr 18, 2020 at 2:30 PM Nick Hall-Patch wrote: > Does anyone know if the "ISES solar cycle Ap progression" graph > (example at http://n5pa.com/swpc-solarcycleapprogression.php) is no > longer being provided? (or being provided elsewhere?) > > NOAA has recently updated their solar cycle progression page > (https://www.swpc.noaa.gov/products/solar-cycle-progression), and it > now includes only sunspots and solar flux progression over the years. > > > Thanks. > > Nick > VE7DXR > > Nick Hall-Patch > Victoria, BC > Canada > > _ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > _____ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector Nick Hall-Patch Victoria, BC Canada _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Topband: Ap progression graph from swpc.noaa.gov
Does anyone know if the "ISES solar cycle Ap progression" graph (example at http://n5pa.com/swpc-solarcycleapprogression.php) is no longer being provided? (or being provided elsewhere?) NOAA has recently updated their solar cycle progression page (https://www.swpc.noaa.gov/products/solar-cycle-progression), and it now includes only sunspots and solar flux progression over the years. Thanks. Nick VE7DXR Nick Hall-Patch Victoria, BC Canada _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Slightly OT - amplifier noise
See http://www.hard-core-dx.com/nordicdx/antenna/special/mfj1026.html Jeff; it was a mod. Nick VE7DXR At 17:59 2020-03-20, Jeff wrote: I thought the 1026 included the BC band, or was that a mod ? Jeff Reynolds Mike Waters wrote: Mike, I based that on what W8JI states on his webpage, which says 1.8 to 20 MHz. https://www.w8ji.com/mfj-1025_1026.htm IIRC, Tom designed that for MFJ. Maybe that was a typo (on either Tom's site or in MFJ's manual). Or perhaps the performance drops off to some degree above 20 MHz. I don't know. 73, Mike W0BTU On Wed, Mar 18, 2020, 10:24 AM Michael Tope wrote: Hi Mike, I was trying to address the particulars of N2IC's situation which involved the higher HF bands (although at this point in the sunspot cycle, perhaps I should have included 20 meters). Reading the manual I have for the MFJ-1026 says "The MFJ-1026 is optimized over the range of 1.8 to 30 MHz". Does the MFJ-1025 only go to 20MHz? 73, Mike W4EF On 3/17/2020 10:31 AM, Mike Waters wrote: Mike, is there any reason why you tested it above 20 MHz? That's outside the 1026's specified frequency range. _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector Nick Hall-Patch Victoria, BC Canada _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: 160m activity and propagation
Isn't the auroral zone centered on the "geomagnetic pole" rather than the "magnetic pole"? Given that the geomagnetic pole is hardly moving at all in comparison with the magnetic pole, that would indicate that the location of the auroral zone itself shouldn't have moved too much since the last solar minimum. 73 Nick VE7DXR At 18:50 2020-02-21, W7RH wrote: Thanks for the comments in this discussion. I have in previous posts commented on the magnetic north pole and it's migration towards Siberia. I feel this has been the primary cause of propagation disturbance at my location. That and I'm at the wrong distance from the aurora itself creating the high absorption. Here are a couple of links to visualize what I perceive is the cause. Fortunately 160m is almost always open somewhere after dark, not necessarily where I want it to be. Yesterday I worked EA7X two hours after sunset and then the band closed. http://wdc.kugi.kyoto-u.ac.jp/poles/polesexp.html https://www.swpc.noaa.gov/ On the NOAA page click on the right hand image of the Aurora and run the 24 hour collection. You can see I'm in the wrong place at the wrong time. 73 Bob W7RH -- W7RH DM35os "It has become appallingly obvious that our technology has exceeded our humanity." - Albert Einstein _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector Nick Hall-Patch Victoria, BC Canada _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Dual RX SDR receivers (diversity capable)
Have you looked at http://www.afedri-sdr.com/index.php/new-afe822x-sdr-net-dual-channel ? 73 Nick VE7DXR At 17:40 2019-01-13, Dan Edward Dba East edwards wrote: the lowly Red Pitaya will do it.. 73, w5xz, dan On Sunday, January 13, 2019, 9:28:34 AM CST, Bjorn SM0MDG wrote: Hi gang, Are there any resources out there listing (and comparing) dual RX SDR receivers? I am interested SDR receivers with dual independent RX channels synchronised primarely for diversity RX. 73 de Björn, SM0MDG SE0X _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector Nick Hall-Patch Victoria, BC Canada _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: WB6RSE Flag type loop question
Does the article referenced then not go on to describe a phased array of two LoG's (Figure 7)? Nick VE7DXR At 21:24 2018-08-01, Joe Subich, W4TV wrote: On 2018-08-01 5:13 PM, Carl Luetzelschwab wrote: That gain value is in the neighborhood of what a Waller Flag does. However, the Waller Flag is a dual loop that trades off signal for pattern. The LOG simply throws away signal due to attenuation of the dirt. The LOG is a horizontally polarized antenna nearly on the "boundary" where the horizontally polarized signal goes to zero. The better the ground (higher conductivity), the worse (lower) the signal level from the LOG (thank you Dr. Maxwell). 73, ... Joe, W4TV _ Topband Reflector Archives - http://www.contesting.com/_topband Nick Hall-Patch Victoria, BC Canada _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: WB6RSE Flag type loop question
DuckDuckGo brought up this at the top of its search: http://kk5jy.net/LoG/ Presumably that is what you mean? best wishes, Nick VE7DXR At 19:04 2018-08-01, CUTTER DAVID via Topband wrote: Drifting the thread slightly: I read an article recently regarding 2 loops of 15ft square separated by 15ft which the author called Loop On Ground, LOG. He claimed good results on receive over a period of a year. It was very low gain but had directional properties and was said to be quiet.I can't lay my hands on the site just now, but it might be of interest. David G3UNA > > On 01 August 2018 at 17:15 donov...@starpower.net wrote: > > Hi Mike, > > A horizontally polarized loop -- or any other horizontally polarized > 160 meter antenna -- has extremely poor sensitivity when installed > less than about 0.1 wavelenght above the ground. Even if you raise > a horizontally polarized loop to about 0.1 wavelength (50 feet on 160 > meters) it will be a poor antenna for DXing because of its insensitivity > to low angles of arrival. > > 73 > Frank > W3LPL > > - Original Message - > > From: "W0MU Mike Fatchett" > To: topband@contesting.com > Sent: Wednesday, August 1, 2018 3:40:10 PM > Subject: Topband: WB6RSE Flag type loop question > > Has anyone tried a loop like this in the Horizontal plane? I suppose > if one had an AZ mount they could try it from horizontal to Vertical. > > His flag build was in the July 2015 QST. > > W0MU > > _ > Topband Reflector Archives - http://www.contesting.com/_topband > > _ > Topband Reflector Archives - http://www.contesting.com/_topband > Sent to: d.cut...@ntlworld.com > _ Topband Reflector Archives - http://www.contesting.com/_topband Nick Hall-Patch Victoria, BC Canada _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Beverage Antenna Tuning
Hi Ash, I see that you are evaluating your Beverage antenna by using SWR. Have you actually adjusted the termination resistance to null medium-wave broadcasters located off the back end of the antenna? If so, what was the value of that termination resistance? If not, it might be worthwhile to make that adjustment in order to understand better your antenna. As others have pointed out however, the Beverage will work well without optimizing its termination, but it sounds as if you would like to understand its operation more clearly. If your ground conductivity is very poor, much of your termination resistance will be made up of the resistance between the ground rod(s) and the earth, and that resistance can be substantial when using short ground rods in poorly conductive ground. Perhaps only a small value of termination resistor will actually be needed, even though the impedance of the antenna is around 500 ohms. And, that termination resistance will possibly vary with the season of the year. I have had to use zero ohms termination at one site, as that provided the best null for a medium-wave broadcast signal off the back end of the Beverage antenna. Perhaps the resistance to earth at that site was even in excess of 500 ohms, so I would have needed to create a better system of ground rods to improve the null further. I imagine the SWR of that antenna varied quite a lot with frequency. The Saudi and Egyptian broadcasters that you will use for nulling are quite powerful I believe, so I hope that they do not suffer from short term fading at night that can make a null difficult to find. best of luck with this project, Nick VE7DXR At 14:33 2018-07-06, Ashraf Chaabane wrote: Hi Mark, Peter, The BC station to be used to minimize the back lobe would be in Egypt or Saoudi Arabia right on the back of my beverage antenna. That should offer signals coming well above 10deg (I presume!). Comment noted regarding how efficient that will be on 1820 kHz. I know Egypt has BC station on Medium Wave which isn't that far from 160m. Frank, I have two 3-feets rods at each end so far with two buried radials at the feed end. I will add radials at the termination side as well as you recommend. For the sake of experimentation, I will play a bit with the termination resistor trying to flatten the SWR curve as much as possible, although, as many said, I shouldn't expect a noticeable improvement in reception. Thank you all and those who wrote me in private. This generous technical support is needed for developing experience on 160 among 3V hams (mostly youngsters). I hope we will be ready with strong 100W signals this winter! 73 from Tunisia Ash 3V8SS/KF5EYY www.kf5eyy.info -- Original Message -- From: donov...@starpower.net To: topband@contesting.com Cc: "Ashraf Chaabane" Sent: 04/07/2018 19:00:33 Subject: Re: Topband: Beverage Antenna Tuning Hello Ash, Your results are normal for a typical Beverage. Receiving performance is not significantly degraded by imperfect matching of the coaxial feedline to the Beverage feed point or by non-optimum termination resistance. You could optimize your matching transformer and termination resistor but the improvement in receiving performance will be very minor. On the other hand, Beverage antenna receiving performance can be significantly degraded by: - nearby antennas, power lines and other long conductors, and - common mode signals coupled into the feedline You could optimize your matching transformer to reduce the VSWR to closer to 1:1 on the frequencies you care about most, but you won't notice any improvement in receiving performance. You could optimize your Beverage termination by: - adding extra ground rods and/or short radials to improve ground resistance stability at the connection to termination resistor. - adjusting the termination resistance to minimize the VSWR excursion as you sweep from 1.5 to about 10 MHz 73 Frank W3LPL From: "Ashraf Chaabane" To: topband@contesting.com Sent: Wednesday, July 4, 2018 2:13:27 PM Subject: Topband: Beverage Antenna Tuning Hi All I measured the SWR in my beverage antenna; the SWR fluctuates between 1.5 and 3 in a range of 1.8 to 7 MHz. (See: https://drive.google.com/drive/folders/0B9AtNpPfAOUMRDNsaXROMG1VUTg?usp=sharing ) I know SWR should not vary too much. However, some people are suggesting adjusting the termination resistor. Others suggest checking the transformer number of windings for a good match. What shall I do? 73 Ash 3V8SS/KF5EYY _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband Nick Hall-Patch Victoria, BC Canada _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Condx from NA to EU last night / sunrise enhancement, or, lack of it
Roger's contention that sunrise peaking was not what it was decades ago has intrigued me, especially considering that he has pointed out that he can still observe the noise floor dropping at sunrise. Others have suggested that they are still seeing sunrise enhancements, either for sunrise at their location, or for at sunrise at the transmitter. But they are usually referencing paths different from those from North America to Europe. I cross-posted Roger's observations to the list maintained by Medium Wave Circle, a European group of experienced DXers who chase long distance receptions at the broadcasters' frequencies of 530-1700kHz. A distinct advantage of propagation observations at such frequencies is that the targets are on the air every day at the same time. (the disadvantage is that target signals are often buried in interference from broadcasters closer to home). The other down side of any such observations up until now is that they are usually as anecdotal as those being related for 160m. Paul Crankshaw, a DXer in Troon, Scotland posted the following: I would concur with that. (referring to Roger's observations) He also posted some further findings that relate to this thread: The following might be of interest to some, though relating to topband it might be marginally off-topic! Digital mode FT8 has revolutionised top band reception here. It is a low power mode with "overs" of just 15 seconds. I have set my recorder so that when it is not recording medium wave at the top of the hour it switches to 1840 kHz were the FT8 activity is. The software I use is JTDX <https://www.release.jtdx.tech/Windows/JTDX-18.0.0.133-GA-win32.zip>https://www.release.jtdx.tech/Windows/JTDX-18.0.0.133-GA-win32.zip Equally you can use WSJT-X <https://physics.princeton.edu/pulsar/k1jt/wsjtx.html>https://physics.princeton.edu/pulsar/k1jt/wsjtx.html A screenshot of JTDX <https://www.dropbox.com/s/oansalwus2dzyzn/jtdx.jpg?dl=0>https://www.dropbox.com/s/oansalwus2dzyzn/jtdx.jpg?dl=0 All stations received may be uploaded automatically to pskreporter which maps reception. Here is my overnight reception plotted by pskreporter. <https://www.dropbox.com/s/15ccpvbiybxh1eb/1feb.jpg?dl=0>https://www.dropbox.com/s/15ccpvbiybxh1eb/1feb.jpg?dl=0 I find that reception of North America / Latin America stations does broadly match MW propagation though west coast North America is more easily received on 1840 kHz. Peak time for WCNA is usually around 0400 although today (this posted at around 0900 on 1 February) I notice a different pattern. The station mapped in WA, W7FI was logged (for last time, it may have been heard earlier) at 0648. The ID station at 0724. No California made it through last night. As I write the band is quite dead. The last couple of stations, one in IL and one in Cuba were received at 0815 UTC So, further food for thought. Paul would have benefited from the his noise levels dropping at local sunrise, but has not seen much effect from that, let alone any sunrise peaks. Are there similar FT8 observations from those in North America who would not have benefited from local sunrise at their locations, but be recording signals from European amateurs as sunrise occurred at their locations? 73 Nick VE7DXR At 19:19 2018-02-01, Roger Kennedy wrote: Actually Dave, I didn't think conditions were exceptional last night . . . They have been much the same almost every night I have been on the band for the past few weeks. (I'm going by the strength of signals received, as well as my reports . . . with stations right across to the West Coast) But the problem is there is often little or no activity ! So I'm hoping that the idea of this regular Wednesday 160m DX Night will prompt more and more stations to come on the band ! Roger G3YRO > Conditions last night from here in the Midwest (Iowa) to Europe were > exceptional. . .probably the best of the season so far. I got ready to > shut down around 0500z and thought I would take a listen before before I > did. I was hearing Europe pretty well including Zone 16 stations. I > called and worked some with 100w while the amp was warming up. I started > CQing when the amp came on and shut down and hour and 20 minutes later > having logged 41 stations. There were a lot of honest S7/S8 signals with > a last a half dozen S9 or better. Had I gotten on earlier I'm sure I > could have worked many more, but the sun was starting to be a factor when > I went QRT. It appears when conditions are good the guys QSY down from > 1840, dust off the keyer, and experience the excitement of working people > they can actually hear. It was great fun. 73. . . Dave, W0FLS _ Topband Reflector A
Re: Topband: sdrWEB not going in my log
Did the Europeans hear your barefoot transmission, but you were not able to hear their barefoot transmission Terry? Or were you both using webSDRs in each others' localities? (and was this on 160m?) Thanks. Nick VE7DXR At 06:44 2018-01-16, terry burge wrote: Well I guess I had to find out what all the fuss was about so I went on line and tried some of these European webSDR's. Just worked OK2RZ and YT1AA. Also heard I5ZSS. Using the SDR it's like shooting fish in the barrel. At least when you plug into the right SDR over there. They are not going in my log but I did find out it is easy to do. And I believe it would get so easy the fascination with working the world would be gone for me. It works but the most of what I got out of it was how strong the Europeans were 'over there' and how poor my reception was here in Oregon. Like nil! So much for that. But before you think there are only a few of those webSDR's, take another think on that. There apparently are dozens, maybe hundreds. Don't think they will care what a few of us old Ham Radio geeks think. Terry KI7M _ Topband Reflector Archives - http://www.contesting.com/_topband Nick Hall-Patch Victoria, BC Canada --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Band Open - But No Sunrise Peak
Thanks for the clarification Dave. When did you last see consistent SR peaks at your location? I suspect that http://www.swpc.noaa.gov/products/solar-cycle-progression shows the source of our difficulties. The highest level of geomagnetic activity in the present cycle started in late 2014. Up to that point, high latitude conditions in this location seemed pretty reasonable overall, considering the progress of the solar cycle, but since then, they've been fairly poor overall. Perhaps quieter geomagnetic conditions overall contribute to the likelihood of the occurrence of sunrise peaks in signal strength? (though that's difficult to tell if there are also no signals heard previous to sunrise due to poor conditions) 73, Nick VE7DXR At 21:30 2018-01-12, daraym...@iowatelecom.net wrote: When I refer to a SR peak in my earlier post, I'm referring to an increase in actual signal levels (with corresponding increase in S/N). 73. . . Dave, W0FLS -Original Message----- From: Nick Hall-Patch Sent: Friday, January 12, 2018 11:23 AM To: Petr Ourednik ; topband@contesting.com Subject: Re: Topband: Band Open - But No Sunrise Peak Wasn't some of the apparent peaking of signals at sunrise due to improved signal to noise levels as noise levels drop at sunrise? 20 years ago for many of us, noise levels did actually drop at sunrise. For many DXers now, (man-made) noise levels stay the same after sunrise, so, no apparent increase in signal strength (actually increase in S/N ratio). This is not to say that there was no "real" increase in signal levels at sunrise 20 years ago, just that it was perhaps less frequent than was thought at the time.If someone has recorded signal strength levels from that period, I'd be happy to be proved wrong. This morning, in western Canada, a medium-wave broadcaster, HLAZ-1566kHz from South Korea was audible until after 1700UT, an hour past local sunrise, with a reasonable sunrise peak.Yesterday, there wasn't much of a sunrise peak, and local noise conditions haven't changed that much over 24 hours. Was any west coaster on 160m on those two mornings? 73, Nick VE7DXR Nick Hall-Patch Victoria, BC Canada --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Band Open - But No Sunrise Peak
Wasn't some of the apparent peaking of signals at sunrise due to improved signal to noise levels as noise levels drop at sunrise? 20 years ago for many of us, noise levels did actually drop at sunrise. For many DXers now, (man-made) noise levels stay the same after sunrise, so, no apparent increase in signal strength (actually increase in S/N ratio). This is not to say that there was no "real" increase in signal levels at sunrise 20 years ago, just that it was perhaps less frequent than was thought at the time.If someone has recorded signal strength levels from that period, I'd be happy to be proved wrong. This morning, in western Canada, a medium-wave broadcaster, HLAZ-1566kHz from South Korea was audible until after 1700UT, an hour past local sunrise, with a reasonable sunrise peak.Yesterday, there wasn't much of a sunrise peak, and local noise conditions haven't changed that much over 24 hours. Was any west coaster on 160m on those two mornings? 73, Nick VE7DXR At 14:52 2018-01-12, Petr Ourednik wrote: Hi all, the original question was about the signals level peak during the SR/SS phenomenon time... did someone noticed the same "No Sunrise peak" behavior please? 73 - Petr, OK1RP On Fri, Jan 12, 2018, at 3:40 PM, Ken Boasi wrote: > High noise levels must be driving people off the band. Conditions have > been generally good in the last week, but activity has been light. > > Have heard several UA9 stations on both 80/160 and worked a few on 80. > Europe has also been in very good on both bands. > > I heard you working the US last night Roger-you were about 579 when I listened. > > I know a number of folks in the NE USA worked UK9AA last night with 'AA > having a good signal for a few hours between 2300-0200z. > > 73, Ken N2ZN > > > On Jan 12, 2018, at 9:04 AM, GEORGE WALLNER wrote: > > > > Some EU stations were S7 in Miami last night, Unfortunately, noise on my TX antenna was also S7. > > > > George > > AA7JV > > > > > > On Fri, 12 Jan 2018 07:34:58 -0500 > > Thomas Hoyer wrote: > >> I must be in a black hole as I have listened every night this week and heard no EU. Probably doesn't help I have an S7 to S9 noise level though > >> Tom > >> W3TA > >> -Original Message- > >> From: Roger Kennedy > >> To: topband > >> Sent: Fri, Jan 12, 2018 4:57 am > >> Subject: Topband: Band Open - But No Sunrise Peak > >> The band has been open for DX from Europe almost every night this week . . . > >> so let's hear some more activity from you North American guys! (I'm > >> usually on from around 23.30 Z) > >> However . . . I'm still amazed that there seems to be no peak in signals > >> around our Sunrise (in the old days, when conditions were much better, signals would usually > >> increase by at least 10 to 20dB, both ways) > >> Roger G3YRO > >> _ > >> 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 -- 73 - Petr, OK1RP B: goo.gl/Fd2JhJ G+: goo.gl/w3u2s9 G+: goo.gl/gP99xq _ Topband Reflector Archives - http://www.contesting.com/_topband Nick Hall-Patch Victoria, BC Canada --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Big 160m openings just before K index spikes
Hi Mark, Earlier this year on this list, K9LA posted the following: With respect to Wolf DF2PY's comment about very good propagation on polar routes when the A index and the solar wind speed are elevated, our understanding of what makes 160m tick is lacking. In other words, "stuff happens". Having said that, there have been similar reports of good propagation on 160m at high latitudes when the K index spikes up. A process that could explain this is tied to changes in the E region and lower F region at elevated K indices. When geomagnetic field activity increases, the atmosphere's electric field (measured in terms of mV/meter) increases. When this happens, the electron density valley above the E region peak can become better developed (deeper and more vertical extent - which would eliminate transits through the absorbing region and eliminate ground reflections). This process comes from a 1984 paper in the Journal of Geophysical Research. It is only a model - I'm not aware of any measurements to confirm that this happens. So "buyer beware". All I can say is - it makes sense. Carl K9LA In addition, it strikes me that there was a recent academic paper that said something about ionospheric layers increasing in height at the onset of a geomagnetic storm, but darned if I can find a copy of that right now. Does anyone else recall this? 73 Nick VE7DXR At 19:37 2017-12-09, Mark Connelly via Topband wrote: The "boost before bust" phenomenon has also been noticed by DX listeners of the AM broadcast band. Here on the US East Coast, some of the more reliable northern European signals are the UK stations on 693, 882, 909, 1089, and 1215 kHz. We used to have the Norway "flamethrower" on 1314 as a great propagation beacon but that station, like many others in northern Europe, has gone dark. When solar flares occur, radiation travels outward at the speed of light, making the trip in a bit over 8 minutes. Charged particles are also ejected: these may take a day or so to reach Earth's ionosphere. The effect of that initial arrival of radiation seems to be enhanced higher latitude northern hemisphere propagation. As the charged particles start coming in and the A/K indices rise, high latitude routes are attenuated. In the early evening here in Massachusetts, for instance on 750 kHz, you would go from good reception of a station in Newfoundland (CBGY, Bonavista Bay) over to a channel dominated by a station in Caracas, Venezuela (YVKS). Northern European signals go away. If anything is coming across the Atlantic at that point it would be African signals such as Mauritania on 783, Canary Islands on 621 etc. Mostly a lot would be heard from Latin America. Brazil, Venezuela, Colombia, and Puerto Rico are quite prominent since many of the more-northerly interferers (US, Canada et al.) are blocked out. Mark Connelly, WA1ION South Yarmouth, MA, USA << Yes Lee I guess we have all seen as in my case enhancement from here to VK under those conditions including places like KH0, JD1 etc. locals for you guys. However the very best of conditions I have seen is when the K index stays very low at 0 or max 1 for several days. Then the big US openings can happen and I can end up working all states in a week contest. If it times correctly with a contest. Bring it on. 73 Clive GM3POI -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Lee STRAHAN Sent: 08 December 2017 17:38 To: topBand List Subject: Topband: Big 160m openings just before K index spikes I have also seen big openings here in Oregon just prior to a big solar event. If I recall correctly it was when I worked the A4 which is huge from the Pacific Northwest. Lee K7TJR _ Topband Reflector Archives - http://www.contesting.com/_topband >> _ Topband Reflector Archives - http://www.contesting.com/_topband Nick Hall-Patch Victoria, BC Canada --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Twist a Flag into a Bowtie?
So, is the ground wire just left "floating", JC?No electrical connection to the antenna itself? Thanks and 73, Nick VE7DXR At 11:23 13-12-16, JC wrote: Hi Nick The wire will reduce loss on the transmission line given a better match and phase. In practice you can see change on the SWR and front back. If you have a good ground you probably won't see anything changing. Regards JC -Original Message----- From: Nick Hall-Patch [mailto:n...@ieee.org] Sent: Monday, December 12, 2016 10:59 PM To: JC Cc: 'topband' Subject: Re: Topband: Twist a Flag into a Bowtie? What kind of improvement in performance is observed by providing a better ground, JC? And, where would a ground wire (counterpoise?) be connected with the DHDL antenna system? Thanks and 73, Nick VE7DXR At 15:38 11-12-16, JC wrote: >Hi Mike and Don > >The DHDL as well as few other antennas, has a hidden component. The >bottom wire parallel to the ground is a transmission line, actually, >any antenna parallel to the ground is a transmission line. A beverage >antenna a is good example. > >The ground is the second leg of the transition line, for a K9AY loop >it is the same, the bottom wire and the ground form a transmission >line. The transmission line allows the Resistor and the Transformer to >be moved to the center of the loop. The VE3DO loop is also exactly the same. > >The same way, a DHDL antenna uses the ground to phase the two loops, if >you elevate the DHDL high far from the ground, the patter changes. The >DHDL is a ground dependent antenna, improving the ground with a ground >wire bellow the antenna can fix some ground problems. > > >My two cents. > >73's >JC > >N4IS > >-Original Message- >From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Don >Kirk >Sent: Sunday, December 11, 2016 10:13 AM >To: D Michael >Cc: topband >Subject: Re: Topband: Twist a Flag into a Bowtie? > >Hi Mike, > >Funny you should ask that. > >A few months ago (September) I was looking at building a smaller size >DHDL using 4Nec2, and there were a few things I saw that I thought >needed improvement (I saw things in the full size DHDL that I thought >needed improvement, it was not limited to the small size DHDL I was >trying to design). Then I started to play around with the location of >its termination resistor as well as routing of wires, and wound up with >what I called the Terminated Bowtie. I built one in my backyard but my >yard is pretty small and the antenna was too close to existing objects >(house and chain link >fence) and I did not realize the S/N improvement that I expected, >nevertheless based on modeling it looks like a winner (9.5 RDF and >front to back ratio versus elevation angle very robust). > >I have attached the preliminary document I put together a few months >ago for you and others to view (it might not be perfect, but should >convey my design / thoughts). I would love someone to build one of >these out in the open to see if the real life build provides results >similar to the 4Nec2 modelling I did. > >Note: Bringing the feedline away from the antenna properly needs to be >looked at to minimize distortion of the pattern. As I recall the >feedline should not drop down to the ground until it's at least 5 feet >away from the antenna, and a greater distance would be best. The >feedline should also use choke with ground rod similar to what's >recommend for other RX antennas we use (beverages, flags, etc.) to >block common mode noise from making its way to the antenna feedpoint. > >Let me know what you think. It might not work, but sure looked good on >paper. > >73, >Don (wd8dsb) > >On Sun, Dec 11, 2016 at 9:41 AM, D Michael wrote: > > > > > > > I have two flag rx ants and I was looking at the DHDL and DK6ED > > Double Loop System V2 and wondering if twisting my Flag rx ants into > > Bowties would improve the forward pattern and make them narrower > > with better front to back. > > I would just ""flip"" the termination resistor end to form a loose > > BOWTIE shape. > > I have no ant modeling software so I have no way to ponder this change. > > Maybe someone could model doing this. > > TNX es 73, Mike W3TS > > _ > > Topband Reflector Archives - http://www.contesting.com/_topband > > >_ >Topband Reflector Archives - http://www.contesting.com/_topband > >_ >Topband Reflector Archives - http://www.contesting.com/_topband Nick Hall-Patch Victoria, BC Canada Nick Hall-Patch Victoria, BC Canada _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Twist a Flag into a Bowtie?
What kind of improvement in performance is observed by providing a better ground, JC? And, where would a ground wire (counterpoise?) be connected with the DHDL antenna system? Thanks and 73, Nick VE7DXR At 15:38 11-12-16, JC wrote: Hi Mike and Don The DHDL as well as few other antennas, has a hidden component. The bottom wire parallel to the ground is a transmission line, actually, any antenna parallel to the ground is a transmission line. A beverage antenna a is good example. The ground is the second leg of the transition line, for a K9AY loop it is the same, the bottom wire and the ground form a transmission line. The transmission line allows the Resistor and the Transformer to be moved to the center of the loop. The VE3DO loop is also exactly the same. The same way, a DHDL antenna uses the ground to phase the two loops, if you elevate the DHDL high far from the ground, the patter changes. The DHDL is a ground dependent antenna, improving the ground with a ground wire bellow the antenna can fix some ground problems. My two cents. 73's JC N4IS -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Don Kirk Sent: Sunday, December 11, 2016 10:13 AM To: D Michael Cc: topband Subject: Re: Topband: Twist a Flag into a Bowtie? Hi Mike, Funny you should ask that. A few months ago (September) I was looking at building a smaller size DHDL using 4Nec2, and there were a few things I saw that I thought needed improvement (I saw things in the full size DHDL that I thought needed improvement, it was not limited to the small size DHDL I was trying to design). Then I started to play around with the location of its termination resistor as well as routing of wires, and wound up with what I called the Terminated Bowtie. I built one in my backyard but my yard is pretty small and the antenna was too close to existing objects (house and chain link fence) and I did not realize the S/N improvement that I expected, nevertheless based on modeling it looks like a winner (9.5 RDF and front to back ratio versus elevation angle very robust). I have attached the preliminary document I put together a few months ago for you and others to view (it might not be perfect, but should convey my design / thoughts). I would love someone to build one of these out in the open to see if the real life build provides results similar to the 4Nec2 modelling I did. Note: Bringing the feedline away from the antenna properly needs to be looked at to minimize distortion of the pattern. As I recall the feedline should not drop down to the ground until it's at least 5 feet away from the antenna, and a greater distance would be best. The feedline should also use choke with ground rod similar to what's recommend for other RX antennas we use (beverages, flags, etc.) to block common mode noise from making its way to the antenna feedpoint. Let me know what you think. It might not work, but sure looked good on paper. 73, Don (wd8dsb) On Sun, Dec 11, 2016 at 9:41 AM, D Michael wrote: > > > I have two flag rx ants and I was looking at the DHDL and DK6ED Double > Loop System V2 and wondering if twisting my Flag rx ants into Bowties > would improve the forward pattern and make them narrower with better > front to back. > I would just ""flip"" the termination resistor end to form a loose > BOWTIE shape. > I have no ant modeling software so I have no way to ponder this change. > Maybe someone could model doing this. > TNX es 73, Mike W3TS > _ > Topband Reflector Archives - http://www.contesting.com/_topband > _ Topband Reflector Archives - http://www.contesting.com/_topband _____ Topband Reflector Archives - http://www.contesting.com/_topband Nick Hall-Patch Victoria, BC Canada _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Bowtie Flags
Thanks Bruce. Sounds like practical constraints led to a worthwhile outcome. 73 Nick VE7DXR At 17:21 12-12-16, K1FZ-Bruce wrote: Nick, Although I did not measure it, the front to back, and front to side is better, overall more quiet. It is receiving toward the Caribbean. Europe, and USA stations, are lower in signal strength. Can often work Caribbean and South American stations through a small pile up when they are not working split. In my case it was a worth while change. The original plan was to be able to drive my car under it. 73 Bruce-K1FZ On Mon, 12 Dec 2016 16:35:14 +, Nick Hall-Patch wrote: What specific improvements did you note when the Delta was raised Bruce? Thanks, Nick VE7DXR At 16:23 12-12-16, K1FZ-Bruce wrote: Dennis, Is there a photo or sketch available of your antenna anywhere by email ? Note: Height above ground helped a lot when my receiving Delta antenna was re-installed higher. The bottom wire went from 3 feet up to ~6 feet at my QTH. 73 Bruce-k1fz http://www.qsl.net/k1fz/flag_antennas.html _ Nick Hall-Patch Victoria, BC Canada _ Topband Reflector Archives - http://www.contesting.com/_topband Nick Hall-Patch Victoria, BC Canada _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Bowtie Flags
What specific improvements did you note when the Delta was raised Bruce? Thanks, Nick VE7DXR At 16:23 12-12-16, K1FZ-Bruce wrote: Dennis, Is there a photo or sketch available of your antenna anywhere by email ? Note: Height above ground helped a lot when my receiving Delta antenna was re-installed higher. The bottom wire went from 3 feet up to ~6 feet at my QTH. 73 Bruce-k1fz http://www.qsl.net/k1fz/flag_antennas.html _ Nick Hall-Patch Victoria, BC Canada _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Back Scatter ?
Hi Bruce, Does the QSB vary regularly at say a 0.5Hz or 1Hz rate? Could it be another station on the channel that is not exactly the same frequency, not strong enough to deliver audio, but strong enough to create a sub-audible beat note? If it is irregular, shouldn't the traditional explanation of a touch of high angle skywave interfering with the small amount of ground wave remaining after nulling the station be sufficient to explain the QSB? 73, Nick VE7DXR At 15:20 15-06-16, K1FZ-Bruce wrote: Been working to optimize the F/B on some antennas, using ground wave stations in the upper BCB band. Noticed that some weaker ~20 mile distant 5 KW stations that the back (reverse) signal has QSB on them. Think we used to call it back scatter years ago. Some are down in the noise and QSB up to about 1 S unit. We used to think back scatter was reflective variations in the ionosphere. Is there any more recent information ? Maybe carbon in varying cloud layers ? 73 Bruce-k1fz http://www.qsl.net/k1fz/beverage_antenna.html _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Waller Flag Question
And if you look at US Patent 2,247,743, it appears that Harold Beverage conceived of a horizontal Flag around 1941. best wishes, Nick At 21:52 06-09-15, you wrote: Bruce wrote on Sept 6. Snip < Check it out http://www.qsl.net/k4fk/presentations/WF-receiver-antennas-SFDXAs.pdf > Bruce, ref to the link above there is a gap in the "History of the Flag Antenna" The earliest fef. to the Terminate loop I have found is in Keenâs Wireless Direction Finding 1927 Ed. Page 75. Keen describes a two turn resistance terminated loop used by Societe Francaicse Radio-Electrique. It resembles the K9AY and uses a similar operation to create a cardiode. 73 Andrew Ikin G8LUG _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Salt-Water Qth!
Please see the articles on sea gain (from technical reports of the BBC Engineering Department), referenced by Chuck Hutton, which I believe addresses this very phenomenon. 73, Nick At 17:13 01-04-15, you wrote: As I recall, the vertical signal strength to low angle DX went up "dramatically" within 2 or less wavelengths of the edge of the high water mark and maybe leveled off as "fantastic" from within 0.5 wavelength. But further and further away past 2 wavelengths, the signal strengths dropped away and had very diminishing effects. I don't recall how far back before the benefits were disappointing but that article has the answers you need. Just scale it for 160 or 80M vs their 40 - 10M data. _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: 160m RX antenna testing surrogates?
The fact that the world outside the Americas has 9kHz rather than 10 kHz separation between broadcasters could help you here Jim. Not as much help for South America, though there is an Argentinian on 1710kHz, but there are US pirates there also. I believe Mark Connelly WA1ION is on this list, and has suggested medium wave broadcast beacons in the past? In Maryland, Asia on 160m would be a longer shot, but you could see if you can hear at least a carrier on 1566kHz from HLAZ South Korea, 1575kHz VoA Thailand, maybe 1593 CNR1 China, 1557 Taiwan. (listening when you have a darkness path of course). These are all high power stations, and tend to dominate their frequencies. North Korea still broadcasts on 2350 and 2850kHz, though they may be more relevant for 80m DX. If you are searching for Australia, 1548 4QD. best wishes, Nick VE7DXR (if you have access to QEX July/August 2001, I did an article on the possibilities of using such stations as beacons for 160m propagation studies, but not as much for your regions of interest unfortunately) At 17:32 20-12-14, you wrote: Here in the US we have the AM broadcast band which I assume other countries can use as 160m testing surrogates to some degree. Are there other DX broadcasters either just above or below 160m that I could use for testing my RX antennas when ham sigs aren't available? My QTH is Maryland, USA. I'm particularly interested in EU and SA as those directions are my best opportunities for adding to my DXCC list. It would be nice if the system of beacons included 160m some day. I've been using those on the upper bands and found them very useful. 73 jim ab3cv _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: WATCH OUT !!Did you get a new cable modem from Comcast? Arris Modem equal lots of QRM
Jameco continues to sell linear wall warts, if you want them new. best wishes, Nick VE7DXR At 05:26 24-10-14, you wrote: On 10/23/2014 3:33 PM, JC wrote: So watch out is you have Comcast cable modem, it is necessary to choke the cable and the AC cord with FT240 # 31. With this fix ,the noise dropped from s8 to s0 but still audible at Doug receiver. By now this should be "Ham Radio 101" -- that is, assume that EVERYTHING with a digital clock, and EVERY switching power supply is a noise source, and be prepared to choke them using my RFI tutorial as a starting point. It's also a VERY good move to replace all switching power supplies with a linear supply, or even a linear supply float charging a battery. I'm doing exactly that with cable modem, WiFi Router, CATV box, Internet "radio," etc. In most cities, it's possible to find linear wall warts at second hand stores for a buck or less, and I also buy them at ham flea markets. And all the gear in my shack (except for computers and power amp), run off my small solar system. 73, Jim K9YC _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Modeling the proverbial "vertical on a beach"
I wonder if they had read the report mentioned by Chuck Hutton a few days ago: http://downloads.bbc.co.uk/rd/pubs/reports/1968-45.pdf It would seem to shed some light on what they observed. There are other, more theoretical, papers of similar vintage that address the issue for those who want to get deeply into it. 73, Nick VE7DXR At 00:22 15-08-14, you wrote: FWIW, here's a site where someone apparently did some tests. Someone posted it on eHam the other day in a similar discussion. http://www.k2kw.com/verticals/verticalinfo.htm 73, Mike www.w0btu.com _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: another carrier
I make it about 125 to 130 degrees from Victoria, BC (local time 10:40am PDT, so, likely ground wave, but not strong). The AM broadcaster on 1680 kHz nulls a few degrees further south. This is using a tuned medium wave loop antenna, so it doesn't resonate on 160m, and local noise tends to queer things in a more north-south direction, but it seems to be a reasonable direction finder otherwise. A west facing Flag with adjustable termination can null the signal also, so I don't think it is at 130+180 = 310 degrees. best wishes, Nick VE7DXR At 17:18 23-03-14, you wrote: The carrier on 1810.8 is still s9 plus 40db here (at 10:15 am), so I guess he/it is local! Jim W1YY/7 Kingston, WA -Original Message- From: Lee K7TJR Sent: Sunday, March 23, 2014 7:20 AM To: topband@contesting.com Subject: Topband: another carrier The 1810.8 carrier is S5 here in the a.m. and is slightly West of North of my QTH in central OR. Lee K7TJR _ 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: Verifying integrity of 75 ohm coax.
What brand of grease is generally used for this purpose? Dow Corning #4 is the available "professional" grease in these parts, but is that too thick? Thanks. best wishes, Nick VE7DXR At 16:06 20-11-13, Bill Wichers wrote: As long as the grease isn't too thick it is fine even on low-pressure contacts. I've seen it used in RJ45 connectors for wireless LAN devices that are used outdoors to help prevent corrosion of the data contacts. On a relatively beefy connector like F, PL259, N, etc., the normal wiping action of the contacts during mating will ensure good electrical contact regardless of the presence of the grease. -Bill > High pressure contacts, I feel fine getting slathering dielectric grease all over > them before making the connection. Examples are like a Battery terminal in a > car, or a spade lug under a screw, or the barrel on an F connector. Something > you actually apply some amount of force to tighten (even just "tight finger > force"). This forces the grease out of the actual metal to metal contact, and > at the same time ensures the metal contacts are enclosed in the grease. > > But for low pressure contacts, e.g. molex pins, or the center pin on an F > connector jack, I think it's best to keep the dielectric grease off the low > pressure contacts. Having it in and around a connector boot or shroud that > goes around a low pressure contact is fine. A good thing in harsh weather or > chemical environment to help keep weather and fumes out. Rubber > connector boots last a lot longer with silicone grease on them. _ Topband Reflector _ Topband Reflector Archives - http://www.contesting.com/_topband
