Re: [Elecraft] Center-fed antennas
Without context you are not making any sense. Quoted material would be considerate. Sent from my iPhone > On Oct 12, 2019, at 08:45, Bill wrote: > > Of course you do! I was only reporting what I have found to be effective in > my particular circumstance. > > Further, not everyone has the manual dexterity or prowess to build things > themselves - hence, they purchase as needed. Hopefully, without recrimination. > > Bill W2BLC on the air for over 60 years! > > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to w...@w2xj.net __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Center-fed antennas
Of course you do! I was only reporting what I have found to be effective in my particular circumstance. Further, not everyone has the manual dexterity or prowess to build things themselves - hence, they purchase as needed. Hopefully, without recrimination. Bill W2BLC on the air for over 60 years! __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Center-fed antennas
On 10/11/2019 2:00 PM, Bill wrote: Might I suggest a Common Mode Filter, such as that sold my myantennas.com All the mumbo-jumbo on that site tells me that they selling snake oil. FAR better, and much less expensive, wind your own using these guidelines. k9yc.com/2018Cookbook.pdf 73, Jim K9YC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Center-fed antennas
On 2019-10-11 3:19 PM, Doug Person wrote: > My favorite is the "Differential-T" 986 which tunes everything with very little effort. Any of the many "T" (single shunt coil, multiple series capacitors) network tuners are high pass networks. They do very little to suppress harmonics and/or phase noise above the transmit frequency. 73, ... Joe, W4TV On 2019-10-11 3:19 PM, Doug Person wrote: Is there any modern-day equivalent to the old Johnson Matchbox? I use several different MFJ tuners with good results. My favorite is the "Differential-T" 986 which tunes everything with very little effort. I don't actually know how efficient it is but it tunes my 132' doublet fed with 450 ohm ladder line very well. I use the antenna mostly on 160-80-60-40-30 where it seems to perform well. The ladder-line comes to a 1:1 high power balun just outside the shack and 10' of rg213 comes inside to the tuner. The only interesting observation is that it seems noisier than my multi-band trapped dipole - as much as 1-2 s units sometimes. Otherwise, if I only had one antenna it would be the doublet. Very versatile. The tuner gives the rig a good under 1.5:1 match 160 through 6. 73, Doug -- KJØF __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Center-fed antennas
Might I suggest a Common Mode Filter, such as that sold my myantennas.com? My standby antenna is an endfed half-wave from the same source. It hangs from the eve corner and is noisy - the kind of noise that comes from today's modern household. I put a CMC Filter on it right at the bulkhead here in the shack. The antenna is now as quiet as my NVIS a hundred feet from the house - which is no local noise at all. I have used the coax through the wall to a balun and 4" feeder with excellent success with a PalStar AT2KD (very similar to the MFJ tuner you mentioned). __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Center-fed antennas
Is there any modern-day equivalent to the old Johnson Matchbox? I use several different MFJ tuners with good results. My favorite is the "Differential-T" 986 which tunes everything with very little effort. I don't actually know how efficient it is but it tunes my 132' doublet fed with 450 ohm ladder line very well. I use the antenna mostly on 160-80-60-40-30 where it seems to perform well. The ladder-line comes to a 1:1 high power balun just outside the shack and 10' of rg213 comes inside to the tuner. The only interesting observation is that it seems noisier than my multi-band trapped dipole - as much as 1-2 s units sometimes. Otherwise, if I only had one antenna it would be the doublet. Very versatile. The tuner gives the rig a good under 1.5:1 match 160 through 6. 73, Doug -- KJØF On 10/10/2019 11:59 PM, Vic Rosenthal wrote: You bet. The Johnson Matchbox is as good as any expensive band pass filter. Victor 4X6GP On 11 Oct 2019, at 2:57, Joe Subich, W4TV wrote: The one "multiband" antenna one can use in a multi-transmitter configuration is the flat-top with open wire feeders and a *Link coupled* tuner. The link coupled tuner is a bandpass filter that significantly reduces harmonic/broadband noise just like the "Q" of a single band antenna. 73, ... Joe, W4TV On 2019-10-10 7:44 PM, Don Wilhelm wrote: Bob, Bandpass filters at each station will help a lot, but they do not have infinite out of band rejection. There is still a huge benefit with single band antennas. My club uses both. Last Field Day (3F operation) one station got on the air with a multiband vertical, and all other operators jumped on that operator to shut him down quickly! The multi-band antenna radiated harmonics of the radio. Even though the transmitter met the -43 dB harmonic required by the FCC, the proximity of the multiband antenna to other antennas caused problems (that station was not using a bandpass filter). So for Field Day multi-station operation, single band antennas, bandpass filters and transmitters with low phase noise are important. We were not able to orient the antennas end to end due to space considerations at the EOC site, so we had to compromise on that, which makes the other factors very important. I need to point out that as an experiment, a 2nd station used an antenna on 20 meters separated from the main 20 meters, and we were able to operate one on CW (K3) at the same time as the other station (Icom) used digital and SSB modes. We had some mutual interference, but it was minimal. The K3 did not interfere much with the Icom due to the K3's low phase noise, but the Icom did raise the background noise level on the K3. 73, Don W3FPR __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to k2vco@gmail.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to d...@kj0f.com -- 73 de Doug -- KJ0F __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Center-fed antennas
In WVARA, we have very good success running several bands on the same antenna at the same time using triplexers. We set up our triband yagis parallel to each other so they are in each other's low-gain area. We have been able to operate CW, SSB, and digital on the same band at the same time. The other things besides well-spaced antenna towers and the triplexer that make this operation possible are using radios with very good receivers and transmitters, currently only Elecraft and Flex are used, and operating QRP. Since we have scored in the top ten for the last 10 or so years, this is a successful formula. 73 Bill AE6JV On 10/10/19 at 4:44 PM, donw...@embarqmail.com (Don Wilhelm) wrote: Bandpass filters at each station will help a lot, but they do not have infinite out of band rejection. There is still a huge benefit with single band antennas. My club uses both. Last Field Day (3F operation) one station got on the air with a multiband vertical, and all other operators jumped on that operator to shut him down quickly! The multi-band antenna radiated harmonics of the radio. Even though the transmitter met the -43 dB harmonic required by the FCC, the proximity of the multiband antenna to other antennas caused problems (that station was not using a bandpass filter). So for Field Day multi-station operation, single band antennas, bandpass filters and transmitters with low phase noise are important. We were not able to orient the antennas end to end due to space considerations at the EOC site, so we had to compromise on that, which makes the other factors very important. I need to point out that as an experiment, a 2nd station used an antenna on 20 meters separated from the main 20 meters, and we were able to operate one on CW (K3) at the same time as the other station (Icom) used digital and SSB modes. We had some mutual interference, but it was minimal. The K3 did not interfere much with the Icom due to the K3's low phase noise, but the Icom did raise the background noise level on the K3. --- Bill Frantz| gets() remains as a monument | Periwinkle (408)356-8506 | to C's continuing support of | 16345 Englewood Ave www.pwpconsult.com | buffer overruns. | Los Gatos, CA 95032 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Center-fed antennas
A simple way to make a center-fed half-wave dipole multi-band is by using alligator clips to disconnect outer section a dipole in order to run on a higher freq band. Simple make a dipole for the lowest freq of interest and then cut the wires at the length for the higher band, attach an alligator clip on the end of the shorter wires and connect the end wires to the shorter wires by use of a small nylon cord. We made 80/40m dipoles for use on the Iditarod Sled Dog Race in this manner and its called an: "Iditarod Special". Most of the remote checkpoint stations use this for an antenna running 100w HF radios to provide race communications support back to Anchorage HQ (Often distances of several hundred miles). Often the temporary dipoles were hung pretty low to the ground so they operated NVIS. Side Note: I just disconnected my old Drake MN-2000 tuner as the auto-tuner in my KXPA100 does the job easily. I use either KX3 or K3 with it. 73, Ed - KL7UW http://www.kl7uw.com Dubus-NA Business mail: dubus...@gmail.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Center-fed antennas
On 10/11/2019 5:32 AM, Wes wrote: I don't suppose your callsign has anything to do with the success of your antennas. Vic's original call was K2VCO. As kids, we worked on 40M traffic nets before heading out to high school in the '50s. We reconnected about 15 years ago after he and I had both moved to W6. Vic knows whereof he speaks. 73, Jim K9YC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Center-fed antennas
On 10/11/2019 5:32 AM, Wes wrote: > I don't suppose your callsign [ 4X6GP ] has anything to do with the success of > your antennas.:-) When I was 4X4UQ in the mid-1960s I had to beat off the Europeans while running 75 watts into a tri-bander about 1 meter above the roof of a 4-story cinder-black building. Elecraft products weren't available yet but the TX was a Hallicrafters HT32B, RX was a Hallicrafters SX101. I still got 55 countries in almost 2 years with just casual QSOs. Those were the days!-- 73 de K2ASP - Phil Kane Elecraft K2/100 s/n 5402 >From a Clearing in the Silicon Forest Beaverton (Washington County) Oregon __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Center-fed antennas
Lyn, That was at the old QTH in CA, here I'm using an inverted L for most bands (temporarily) and a dipole for 80M (which came down in a windstorm, couldn't take the weight of the 10' branch that hit it). The match for 80M on the L is well beyond the range of the KAT500. I'm shifting to a SteppIR DB36 (80-6M) and will single band the Inverted L. The tower is up, I'm assembling the antenna now, in a race to beat winter (already snowed twice in the last two weeks). Next year, I'll make a new L in a better location and add a tuning circuit to the L to allow it to resonate on 80/160M, giving me an option for 80, rotatable dipole or vertical (and two RBOG) or diversity a few different ways. Because of the lower noise here, the L plays well on 160M and I've enjoyed spending considerable time on the band. My original point was to encourage simply putting up some wire; it will radiate and it's a cheap and fun way to learn. Center fed makes it much easier to tame (but that depends on what each leg is near too). Because of local conditions (and lack of height), my dipole was 370', ~60' of 450 ohm window line, 4:1 common mode choke, 10' of coax. It had plenty of pointy pattern spikes, not always in the needed direction and on 40M it absolutely ROCKED. It was specifically NON-resonant on any ham band yet provided some gain on most bands, once the tuner managed the load. Even the existing (will be moved/rebuilt next spring) 160M Inverted L was a 20 minute install that shouldn't work(but gave me over 100 Top Band DX contacts last winter); simply a piece of wire over a tree (at 65'), a 1:1 CMC bonded to a water pipe for counterpoise (NOT efficient) and coax to the shack. It's brought a lot of fun to ham radio (now that I can hear without sub/urban noise). 73, Rick wa6nhc North Idaho On 10/11/2019 8:52 AM, Lyn Norstad wrote: Rick - You may have a balun issue. I had problems too until I switched to the 1:1 / 4:1 hybrid (based on antenna analyzer measurements). And now, 160m matches fine for me. In fact, I made over 200 contacts (FT8, and mostly stateside) on 160m last week. The KAT500 is "supposedly" limited to matching up to a 10:1 SWR. That added 4:1 balun really brought the 160m impedance down to a manageable (and matchable) level. My ladder line feed is about 160 feet, then the balun, and finally about 13 feet of RG8XU to the KAT500. 73 Lyn, WØLEN -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Rick WA6NHC Sent: Thursday, October 10, 2019 6:17 PM To: elecraft@mailman.qth.net Subject: Re: [Elecraft] Center-fed antennas I have over 200 countries on a similar antenna, though I had to use another tuner than the KAT500, for 160M. Average height was about 35'. Just keep the coax short, like under 10' and as much center fed wire as you can put in the air, it'll play. It won't rock your world, it'll make you work for some of the DX, but that teaches patience and operating technique, still win-win. Rick nhc On 10/10/2019 1:56 PM, Lyn Norstad wrote: I'm having great success with a horizontal center-fed "dipole" that has been sized (360 feet long) to be an Extended Double Zepp (4.7 dbi gain) and cut for the low end of 80 meters. I feed it with 600 ohm "True" Ladder Line from a Balun Designs Hybrid Balun (1:1 Current and 4:1 Voltage all in one case). A short run of coax from the balun to my KAT500, and I am in business at any frequency on 160 - 6 meters. It's oriented to be an effective NVIS radiator in a N-S pattern on 80m, by design, and to have major lobes on the other bands in other directions - also by design. For me, it's the most efficient and effective way to utilize our lot space (400 feet clear) and still be "under the radar" in our HOA. Birds seem to like it, and I find that it seems to be especially attractive to Hummingbirds, my XYL's favorites. A win-win, in my book. 73 Lyn, WØLEN -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Al Lorona Sent: Thursday, October 10, 2019 3:25 PM To: elecraft@mailman.qth.net; David Gilbert Subject: [Elecraft] Center-fed antennas My experience with single vertical or sloping wires is exactly the same as AB7E's. I have, over almost twice as many Field Days as Dave, come to a similar conclusion, with the slight difference being my preference for an "all-band dipole" fed with balanced line. This obviates the balun and reduces feedline loss to negligible, so obviously I am maximizing efficiency at the expense of any other possible advantage. (I can usually hear much better than I can be heard... so thus far this has been a valid decision.) To sum up what I and what I think Dave are
Re: [Elecraft] Center-fed antennas
Wow! We're way over the single topic posting limit on this thread. Let's end it for now in the interest of helping others survive email overload. 73, Eric /mooderator.. elecraft.com/ On 10/11/2019 8:52 AM, Lyn Norstad wrote: Rick - You may have a balun issue. I had problems too until I switched to the 1:1 / 4:1 hybrid (based on antenna analyzer measurements). And now, 160m matches fine for me. In fact, I made over 200 contacts (FT8, and mostly stateside) on 160m last week. The KAT500 is "supposedly" limited to matching up to a 10:1 SWR. That added 4:1 balun really brought the 160m impedance down to a manageable (and matchable) level. My ladder line feed is about 160 feet, then the balun, and finally about 13 feet of RG8XU to the KAT500. 73 Lyn, WØLEN __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Center-fed antennas
Rick - You may have a balun issue. I had problems too until I switched to the 1:1 / 4:1 hybrid (based on antenna analyzer measurements). And now, 160m matches fine for me. In fact, I made over 200 contacts (FT8, and mostly stateside) on 160m last week. The KAT500 is "supposedly" limited to matching up to a 10:1 SWR. That added 4:1 balun really brought the 160m impedance down to a manageable (and matchable) level. My ladder line feed is about 160 feet, then the balun, and finally about 13 feet of RG8XU to the KAT500. 73 Lyn, WØLEN -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Rick WA6NHC Sent: Thursday, October 10, 2019 6:17 PM To: elecraft@mailman.qth.net Subject: Re: [Elecraft] Center-fed antennas I have over 200 countries on a similar antenna, though I had to use another tuner than the KAT500, for 160M. Average height was about 35'. Just keep the coax short, like under 10' and as much center fed wire as you can put in the air, it'll play. It won't rock your world, it'll make you work for some of the DX, but that teaches patience and operating technique, still win-win. Rick nhc On 10/10/2019 1:56 PM, Lyn Norstad wrote: > I'm having great success with a horizontal center-fed "dipole" that has been > sized (360 feet long) to be an Extended Double Zepp (4.7 dbi gain) and cut > for the low end of 80 meters. I feed it with 600 ohm "True" Ladder Line from > a Balun Designs Hybrid Balun (1:1 Current and 4:1 Voltage all in one case). > A short run of coax from the balun to my KAT500, and I am in business at any > frequency on 160 - 6 meters. > > It's oriented to be an effective NVIS radiator in a N-S pattern on 80m, by > design, and to have major lobes on the other bands in other directions - also > by design. For me, it's the most efficient and effective way to utilize our > lot space (400 feet clear) and still be "under the radar" in our HOA. > > Birds seem to like it, and I find that it seems to be especially attractive > to Hummingbirds, my XYL's favorites. A win-win, in my book. > > 73 > Lyn, WØLEN > > > -Original Message- > From: elecraft-boun...@mailman.qth.net > [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Al Lorona > Sent: Thursday, October 10, 2019 3:25 PM > To: elecraft@mailman.qth.net; David Gilbert > Subject: [Elecraft] Center-fed antennas > > My experience with single vertical or sloping wires is exactly the same as > AB7E's. I have, over almost twice as many Field Days as Dave, come to a > similar conclusion, with the slight difference being my preference for an > "all-band dipole" fed with balanced line. This obviates the balun and reduces > feedline loss to negligible, so obviously I am maximizing efficiency at the > expense of any other possible advantage. (I can usually hear much better than > I can be heard... so thus far this has been a valid decision.) > > To sum up what I and what I think Dave are saying, you can't beat a > horizontal, center-fed wire up as high as you can get it. Its simplicity, the > flexibility it gives you to QSY (with a good tuner), and its high efficiency > are almost unbeatable. > > As a side note, the center-fed horizontal wire I have used here at home is > totally non-resonant. I don't even know how long it is. Once you give up the > obsession with resonant antenna length, you gain a huge freedom of choice. > > In the bottom of the sunspot cycle, these advantages are somewhat reduced > because an op, especially on Field Day, might opt to forget about any band > higher than 20 meters -- and these days even 20 is questionable. This means > you can probably make do with coaxial cable and a balun for operation on 2 or > 3 bands but the general idea still holds. > > Al W6LX > > >> Yes, a center fed normal dipole with the middle (high current portion) >> higher off the ground (say 50 feet for 40m) and a common mode choke at >> the feedpoint would almost assuredly perform better. >> >> 73, >> Dave AB7E > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to l...@lnainc.com > > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:
Re: [Elecraft] Center-fed antennas
Ha ha, that's a good one, I too have a 20dB callsign. Not always but I'm sure on occasion it helps. I often get 10 to 20 over nine reports running 100 watts to a 2 element (Force 12 C3 @ 24m) from Europe when more powerful stations from there make only 5-6 to 5-7 here. Martin, HS0ZED On 11/10/2019 19:32, Wes wrote: I don't suppose your callsign has anything to do with the success of your antennas.:-) Wes N7WS On 10/10/2019 10:54 PM, Vic Rosenthal wrote: Things I’ve learned by experience: In 63 years as a ham, I’ve had several :-) HF antennas. The ones that gave me the greatest overall satisfaction have been balanced, horizontal antennas. The worst have been verticals with inadequate radial systems or low random-length wires. Inverted Vs with angles less than 90 degrees between the wires are not much good, either. There is no simpler way to make an efficient multiband antenna than to feed a dipole of at least 1/2 wavelength at the lowest frequency with open wire line. With some care in choosing the length of the line, a 1/4 wave dipole can work almost as well. I’ve worked over 300 countries on CW in the last 5 years on the bands from 40-10m with a 10m long rotary dipole, in an urban area (it is up 35m on a building and I run a kW, I admit). I regularly bust pileups on 40m with it. 1:1 baluns work to feed open wire lines, but can become inefficient in some circumstances and heat up. It’s possible to solve this by compensating for reactance with a pair of capacitors or inductors before the balun, but a better solution is a true balanced antenna tuner. “True Ladder Line” is a good product, but it’s easy to make your own, and you can use no. 12 (2 mm) wire for lower loss. Sometimes a 4:1 balun may give a better match, but it will be less efficient (heat) and do a poorer job of keeping RF out of the shack. Nothing has worked better for me at cleaning up RF in the shack than an old Johnson Matchbox, a true balanced tuner. Victor 4X6GP __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to hs0...@gmail.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Center-fed antennas
I don't suppose your callsign has anything to do with the success of your antennas.:-) Wes N7WS On 10/10/2019 10:54 PM, Vic Rosenthal wrote: Things I’ve learned by experience: In 63 years as a ham, I’ve had several :-) HF antennas. The ones that gave me the greatest overall satisfaction have been balanced, horizontal antennas. The worst have been verticals with inadequate radial systems or low random-length wires. Inverted Vs with angles less than 90 degrees between the wires are not much good, either. There is no simpler way to make an efficient multiband antenna than to feed a dipole of at least 1/2 wavelength at the lowest frequency with open wire line. With some care in choosing the length of the line, a 1/4 wave dipole can work almost as well. I’ve worked over 300 countries on CW in the last 5 years on the bands from 40-10m with a 10m long rotary dipole, in an urban area (it is up 35m on a building and I run a kW, I admit). I regularly bust pileups on 40m with it. 1:1 baluns work to feed open wire lines, but can become inefficient in some circumstances and heat up. It’s possible to solve this by compensating for reactance with a pair of capacitors or inductors before the balun, but a better solution is a true balanced antenna tuner. “True Ladder Line” is a good product, but it’s easy to make your own, and you can use no. 12 (2 mm) wire for lower loss. Sometimes a 4:1 balun may give a better match, but it will be less efficient (heat) and do a poorer job of keeping RF out of the shack. Nothing has worked better for me at cleaning up RF in the shack than an old Johnson Matchbox, a true balanced tuner. Victor 4X6GP __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Center-fed antennas
I don't do field day. I've been using monoband dipoles so far for portable operations due to cost and weight constraints. They work incredibly well, and I hope to go out with a high Q antenna for 30m and a long pole to try end fed vertical. (My long pole seems stuck in the post! Courier emailed.). That said, an antenna which really should be 30m only due to its resonant matching circuit can be operated on neighbouring bands using the KX3's tuner. I've had contacts over reasonable distance on 40m with it. The multiband antennae seem attractive for things like SOTA and single station operation. At the moment I need to drop my antenna and change links around to change band. It doesn't take too long to be fair. I'll experiment with a multiband off centre fed antenna which, even if it ends up too heavy to carry up a mountain, could make a useful home station antenna. At the moment my portable setup is set up in the garden but I wonder how well the home made antenna will stand up to our increasingly winter weather. - Richard On Fri, 11 Oct 2019 at 00:57, Al Lorona wrote: > Fair enough, but it kinda goes without saying that in a group FD with 1 > station per band they'll use resonant, single-band antennas. If this is our > best argument against the 'multiband dipole', then that antenna still holds > its own pretty well in a multitude of other situations. > > I have always found a deep resistance and opposition to this antenna. > Whether it's an unwillingness to use antenna tuners, which many hams have, > or an undue fear of noise, which some hams have, or a belief that open-wire > line is noisier/weirder/harder/impossible-to-go-through-walls, which many > hams believe, the visceral reaction against this antenna always amazes and > baffles me. > > Please forgive my belligerence... the Dodgers lost and I've been in a sour > mood all day. > > Al W6LX > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to richard.corfi...@gmail.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Center-fed antennas
You bet. The Johnson Matchbox is as good as any expensive band pass filter. Victor 4X6GP > On 11 Oct 2019, at 2:57, Joe Subich, W4TV wrote: > > > The one "multiband" antenna one can use in a multi-transmitter > configuration is the flat-top with open wire feeders and a > *Link coupled* tuner. The link coupled tuner is a bandpass filter > that significantly reduces harmonic/broadband noise just like the > "Q" of a single band antenna. > > 73, > > ... Joe, W4TV > > >> On 2019-10-10 7:44 PM, Don Wilhelm wrote: >> Bob, >> Bandpass filters at each station will help a lot, but they do not have >> infinite out of band rejection. >> There is still a huge benefit with single band antennas. My club uses both. >> Last Field Day (3F operation) one station got on the air with a multiband >> vertical, and all other operators jumped on that operator to shut him down >> quickly! The multi-band antenna radiated harmonics of the radio. Even >> though the transmitter met the -43 dB harmonic required by the FCC, the >> proximity of the multiband antenna to other antennas caused problems (that >> station was not using a bandpass filter). >> So for Field Day multi-station operation, single band antennas, bandpass >> filters and transmitters with low phase noise are important. We were not >> able to orient the antennas end to end due to space considerations at the >> EOC site, so we had to compromise on that, which makes the other factors >> very important. >> I need to point out that as an experiment, a 2nd station used an antenna on >> 20 meters separated from the main 20 meters, and we were able to operate one >> on CW (K3) at the same time as the other station (Icom) used digital and SSB >> modes. We had some mutual interference, but it was minimal. The K3 did not >> interfere much with the Icom due to the K3's low phase noise, but the Icom >> did raise the background noise level on the K3. >> 73, >> Don W3FPR > > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to k2vco@gmail.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Center-fed antennas
Things I’ve learned by experience: In 63 years as a ham, I’ve had several :-) HF antennas. The ones that gave me the greatest overall satisfaction have been balanced, horizontal antennas. The worst have been verticals with inadequate radial systems or low random-length wires. Inverted Vs with angles less than 90 degrees between the wires are not much good, either. There is no simpler way to make an efficient multiband antenna than to feed a dipole of at least 1/2 wavelength at the lowest frequency with open wire line. With some care in choosing the length of the line, a 1/4 wave dipole can work almost as well. I’ve worked over 300 countries on CW in the last 5 years on the bands from 40-10m with a 10m long rotary dipole, in an urban area (it is up 35m on a building and I run a kW, I admit). I regularly bust pileups on 40m with it. 1:1 baluns work to feed open wire lines, but can become inefficient in some circumstances and heat up. It’s possible to solve this by compensating for reactance with a pair of capacitors or inductors before the balun, but a better solution is a true balanced antenna tuner. “True Ladder Line” is a good product, but it’s easy to make your own, and you can use no. 12 (2 mm) wire for lower loss. Sometimes a 4:1 balun may give a better match, but it will be less efficient (heat) and do a poorer job of keeping RF out of the shack. Nothing has worked better for me at cleaning up RF in the shack than an old Johnson Matchbox, a true balanced tuner. Victor 4X6GP > On 10 Oct 2019, at 23:56, Lyn Norstad wrote: > > I'm having great success with a horizontal center-fed "dipole" that has been > sized (360 feet long) to be an Extended Double Zepp (4.7 dbi gain) and cut > for the low end of 80 meters. I feed it with 600 ohm "True" Ladder Line from > a Balun Designs Hybrid Balun (1:1 Current and 4:1 Voltage all in one case). > A short run of coax from the balun to my KAT500, and I am in business at any > frequency on 160 - 6 meters. > > It's oriented to be an effective NVIS radiator in a N-S pattern on 80m, by > design, and to have major lobes on the other bands in other directions - also > by design. For me, it's the most efficient and effective way to utilize our > lot space (400 feet clear) and still be "under the radar" in our HOA. > > Birds seem to like it, and I find that it seems to be especially attractive > to Hummingbirds, my XYL's favorites. A win-win, in my book. > > 73 > Lyn, WØLEN > > > -Original Message- > From: elecraft-boun...@mailman.qth.net > [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Al Lorona > Sent: Thursday, October 10, 2019 3:25 PM > To: elecraft@mailman.qth.net; David Gilbert > Subject: [Elecraft] Center-fed antennas > > My experience with single vertical or sloping wires is exactly the same as > AB7E's. I have, over almost twice as many Field Days as Dave, come to a > similar conclusion, with the slight difference being my preference for an > "all-band dipole" fed with balanced line. This obviates the balun and reduces > feedline loss to negligible, so obviously I am maximizing efficiency at the > expense of any other possible advantage. (I can usually hear much better than > I can be heard... so thus far this has been a valid decision.) > > To sum up what I and what I think Dave are saying, you can't beat a > horizontal, center-fed wire up as high as you can get it. Its simplicity, the > flexibility it gives you to QSY (with a good tuner), and its high efficiency > are almost unbeatable. > > As a side note, the center-fed horizontal wire I have used here at home is > totally non-resonant. I don't even know how long it is. Once you give up the > obsession with resonant antenna length, you gain a huge freedom of choice. > > In the bottom of the sunspot cycle, these advantages are somewhat reduced > because an op, especially on Field Day, might opt to forget about any band > higher than 20 meters -- and these days even 20 is questionable. This means > you can probably make do with coaxial cable and a balun for operation on 2 or > 3 bands but the general idea still holds. > > Al W6LX > > >> Yes, a center fed normal dipole with the middle (high current portion) >> higher off the ground (say 50 feet for 40m) and a common mode choke at >> the feedpoint would almost assuredly perform better. >> >> 73, >> Dave AB7E > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please
Re: [Elecraft] Center-fed antennas
On 10/10/2019 4:56 PM, Al Lorona wrote: an undue fear of noise, which some hams have, NO fear of noise is undue. It is EVERYWHERE, and it gets worse every day! 73, Jim K9YC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Center-fed antennas
Extra Class licensees vs. Extra Class Operators ... huge delta there ... -- 73 de Mike Flowers, K6MKF, NCDXC - "It's about DX!" > On Oct 10, 2019, at 4:12 PM, Bob McGraw K4TAX wrote: > > I used my Johnson Matchbox at our Field Day event about 3 years ago. I > went through each band and several frequencies on each band and compiled a > written chart identifying the settings for each band/frequency.After 2 > hours of trying to work stations on 20M, the radio failed and they came to > wake me from my late night nap. The result is the Matchbox was adjusted for > 80M in the CW portion and the operators were complaining of high SWR and no > power output on 20M. It took 2 hrs for them to observe this?I was > amazed at the number of "Extra Class" operators at the site that thought the > tuner was automatic and would change with band / frequency changes on the > radio. The radio by the way WAS NOT an Elecraft product. > > 73 > > Bob, K4TAX > > > >> On 10/10/2019 7:35 PM, Don Wilhelm wrote: >> Joe, >> >> I agree completely, bring your Johnson Matchbox to the next Field Day! Or >> even your old plug-in coil open frame link coupled balanced tuner. >> >> Who has a link coupled tuner (like the Johnson Matchbox) these days? Those >> are big boat anchor box these days (and hard to find). I have one that sees >> little use, but I am not willing to part with it. It does a good job when >> needed. >> >> Most autotuners are of the L-network design and the manual tuners are >> typically T-network - the L-network can be a high pass or a low pass filter, >> but the more common T-network is always a high pass filter. If one has an >> old Collins tuner, it may be a Pi-network which is a low pass filter. >> >> As you pointed out, the link coupled tuner is a bandpass filter, but fixed >> tune bandpass filters will do just as well for multi-station operation. >> >> 73, >> Don W3FPR >> > > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to mike.flow...@gmail.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Center-fed antennas
That's a sad commentary on the state of modern ham radio To, k2bew On Thu, Oct 10, 2019, 10:12 PM Bob McGraw K4TAX wrote: > I used my Johnson Matchbox at our Field Day event about 3 years ago. I > went through each band and several frequencies on each band and compiled > a written chart identifying the settings for each band/frequency. > After 2 hours of trying to work stations on 20M, the radio failed and > they came to wake me from my late night nap. The result is the > Matchbox was adjusted for 80M in the CW portion and the operators were > complaining of high SWR and no power output on 20M. It took 2 hrs for > them to observe this?I was amazed at the number of "Extra Class" > operators at the site that thought the tuner was automatic and would > change with band / frequency changes on the radio. The radio by the way > WAS NOT an Elecraft product. > > 73 > > Bob, K4TAX > > > > On 10/10/2019 7:35 PM, Don Wilhelm wrote: > > Joe, > > > > I agree completely, bring your Johnson Matchbox to the next Field Day! > > Or even your old plug-in coil open frame link coupled balanced tuner. > > > > Who has a link coupled tuner (like the Johnson Matchbox) these days? > > Those are big boat anchor box these days (and hard to find). I have > > one that sees little use, but I am not willing to part with it. It > > does a good job when needed. > > > > Most autotuners are of the L-network design and the manual tuners are > > typically T-network - the L-network can be a high pass or a low pass > > filter, but the more common T-network is always a high pass filter. > > If one has an old Collins tuner, it may be a Pi-network which is a low > > pass filter. > > > > As you pointed out, the link coupled tuner is a bandpass filter, but > > fixed tune bandpass filters will do just as well for multi-station > > operation. > > > > 73, > > Don W3FPR > > > > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to tombew...@gmail.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Center-fed antennas
I used my Johnson Matchbox at our Field Day event about 3 years ago. I went through each band and several frequencies on each band and compiled a written chart identifying the settings for each band/frequency. After 2 hours of trying to work stations on 20M, the radio failed and they came to wake me from my late night nap. The result is the Matchbox was adjusted for 80M in the CW portion and the operators were complaining of high SWR and no power output on 20M. It took 2 hrs for them to observe this? I was amazed at the number of "Extra Class" operators at the site that thought the tuner was automatic and would change with band / frequency changes on the radio. The radio by the way WAS NOT an Elecraft product. 73 Bob, K4TAX On 10/10/2019 7:35 PM, Don Wilhelm wrote: Joe, I agree completely, bring your Johnson Matchbox to the next Field Day! Or even your old plug-in coil open frame link coupled balanced tuner. Who has a link coupled tuner (like the Johnson Matchbox) these days? Those are big boat anchor box these days (and hard to find). I have one that sees little use, but I am not willing to part with it. It does a good job when needed. Most autotuners are of the L-network design and the manual tuners are typically T-network - the L-network can be a high pass or a low pass filter, but the more common T-network is always a high pass filter. If one has an old Collins tuner, it may be a Pi-network which is a low pass filter. As you pointed out, the link coupled tuner is a bandpass filter, but fixed tune bandpass filters will do just as well for multi-station operation. 73, Don W3FPR __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Center-fed antennas
At W4NJA (3A) for Field Day we use three Dipoles (Cut for the low end of 80 meters) fed with 450 Ohm ladder line into a DXEngineering Balun with less than ten feet of coax into the rig. The feed line is cut at odd multiples and the antennas are spaced in a straight line end to end with separation of course. We can run three stations on the same band but different modes with no interaction. We used to use G5RV's, verticals, beams etc. but have opted for this configuration because it works. No problem with K3's, Omni VII's tuners to tune the bands. I have the actual length's that the three are cut for but they are stored at another location. I actually got the information from DXEngineering somewhere on their web pages. Ed.. AB4IQ -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Don Wilhelm Sent: Thursday, October 10, 2019 6:44 PM To: Bob McGraw K4TAX ; elecraft@mailman.qth.net Subject: Re: [Elecraft] Center-fed antennas Bob, Bandpass filters at each station will help a lot, but they do not have infinite out of band rejection. There is still a huge benefit with single band antennas. My club uses both. Last Field Day (3F operation) one station got on the air with a multiband vertical, and all other operators jumped on that operator to shut him down quickly! The multi-band antenna radiated harmonics of the radio. Even though the transmitter met the -43 dB harmonic required by the FCC, the proximity of the multiband antenna to other antennas caused problems (that station was not using a bandpass filter). So for Field Day multi-station operation, single band antennas, bandpass filters and transmitters with low phase noise are important. We were not able to orient the antennas end to end due to space considerations at the EOC site, so we had to compromise on that, which makes the other factors very important. I need to point out that as an experiment, a 2nd station used an antenna on 20 meters separated from the main 20 meters, and we were able to operate one on CW (K3) at the same time as the other station (Icom) used digital and SSB modes. We had some mutual interference, but it was minimal. The K3 did not interfere much with the Icom due to the K3's low phase noise, but the Icom did raise the background noise level on the K3. 73, Don W3FPR On 10/10/2019 7:12 PM, Bob McGraw K4TAX wrote: > I thought a Band Pass Filter at each station resolved that issue. > > 73 > > Bob, K4TAX > > On 10/10/2019 5:27 PM, Ken G Kopp wrote: >> Well-said, Don. >> >> 73! >> >> Ken Kopp - K0PP >> >> On Thu, Oct 10, 2019, 16:23 Don Wilhelm wrote: >> >>> All this talk of multi-band antennas for Field Day ignores the >>> problem of multi-station Field Day operation. >>> There is sufficient pickup of one transmitter's energy on the >>> antenna being used by a receiver on another band. >>> For that reason, my club has banned the use of multiband antennas >>> for Field Day operation. >>> >>> For a single station Field Day operation, the multiband antennas are >>> great. >>> >>> 73, >>> Don W3FPR >>> __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to ab...@comcast.net __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Center-fed antennas
Joe, I agree completely, bring your Johnson Matchbox to the next Field Day! Or even your old plug-in coil open frame link coupled balanced tuner. Who has a link coupled tuner (like the Johnson Matchbox) these days? Those are big boat anchor box these days (and hard to find). I have one that sees little use, but I am not willing to part with it. It does a good job when needed. Most autotuners are of the L-network design and the manual tuners are typically T-network - the L-network can be a high pass or a low pass filter, but the more common T-network is always a high pass filter. If one has an old Collins tuner, it may be a Pi-network which is a low pass filter. As you pointed out, the link coupled tuner is a bandpass filter, but fixed tune bandpass filters will do just as well for multi-station operation. 73, Don W3FPR On 10/10/2019 7:57 PM, Joe Subich, W4TV wrote: The one "multiband" antenna one can use in a multi-transmitter configuration is the flat-top with open wire feeders and a *Link coupled* tuner. The link coupled tuner is a bandpass filter that significantly reduces harmonic/broadband noise just like the "Q" of a single band antenna. 73, ... Joe, W4TV __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Center-fed antennas
As usual, there are exceptions to everything. A multi-band beam, such as a C3S or the modern equivalent, will perform incredibly well when used with bandpass filters and a triplexer. The 10,15 and 20 meter stations all will use the antenna through the triplexer/BPFs with no issues. This also turns out to be a favorite setup for many SO2R and M/2 stations at both low and high power. The key is port-to-port isolation through the triplexer/BPFs. It is extremely important that all components can handle the power level in use. Also very important is that the radios have very low spurs and phase noise (i.e. need to have clean signals on transmit). The K3/K3S meets the bill, as do recent Flex Radio SDRs. As Rob Sherwood has pointed out recently, the transmit issue (See Oct QST and hi Dayton Contest Forum talk this past May) is pretty big in most radios. They have been paying attention to receiver issues, but not transmitter. We are very lucky that Wayne, Eric and friends have been p aying attention to this issue for many years. 73! Jack, W6FB > On Oct 10, 2019, at 4:44 PM, Don Wilhelm wrote: > > Bob, > > Bandpass filters at each station will help a lot, but they do not have > infinite out of band rejection. > There is still a huge benefit with single band antennas. My club uses both. > > Last Field Day (3F operation) one station got on the air with a multiband > vertical, and all other operators jumped on that operator to shut him down > quickly! The multi-band antenna radiated harmonics of the radio. Even > though the transmitter met the -43 dB harmonic required by the FCC, the > proximity of the multiband antenna to other antennas caused problems (that > station was not using a bandpass filter). > > So for Field Day multi-station operation, single band antennas, bandpass > filters and transmitters with low phase noise are important. We were not > able to orient the antennas end to end due to space considerations at the EOC > site, so we had to compromise on that, which makes the other factors very > important. > > I need to point out that as an experiment, a 2nd station used an antenna on > 20 meters separated from the main 20 meters, and we were able to operate one > on CW (K3) at the same time as the other station (Icom) used digital and SSB > modes. We had some mutual interference, but it was minimal. The K3 did not > interfere much with the Icom due to the K3's low phase noise, but the Icom > did raise the background noise level on the K3. > > 73, > Don W3FPR > > On 10/10/2019 7:12 PM, Bob McGraw K4TAX wrote: >> I thought a Band Pass Filter at each station resolved that issue. >> 73 >> Bob, K4TAX >> On 10/10/2019 5:27 PM, Ken G Kopp wrote: >>> Well-said, Don. >>> >>> 73! >>> >>> Ken Kopp - K0PP >>> >>> On Thu, Oct 10, 2019, 16:23 Don Wilhelm wrote: >>> All this talk of multi-band antennas for Field Day ignores the problem of multi-station Field Day operation. There is sufficient pickup of one transmitter's energy on the antenna being used by a receiver on another band. For that reason, my club has banned the use of multiband antennas for Field Day operation. For a single station Field Day operation, the multiband antennas are great. 73, Don W3FPR > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to jackbrin...@me.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Center-fed antennas
The one "multiband" antenna one can use in a multi-transmitter configuration is the flat-top with open wire feeders and a *Link coupled* tuner. The link coupled tuner is a bandpass filter that significantly reduces harmonic/broadband noise just like the "Q" of a single band antenna. 73, ... Joe, W4TV On 2019-10-10 7:44 PM, Don Wilhelm wrote: Bob, Bandpass filters at each station will help a lot, but they do not have infinite out of band rejection. There is still a huge benefit with single band antennas. My club uses both. Last Field Day (3F operation) one station got on the air with a multiband vertical, and all other operators jumped on that operator to shut him down quickly! The multi-band antenna radiated harmonics of the radio. Even though the transmitter met the -43 dB harmonic required by the FCC, the proximity of the multiband antenna to other antennas caused problems (that station was not using a bandpass filter). So for Field Day multi-station operation, single band antennas, bandpass filters and transmitters with low phase noise are important. We were not able to orient the antennas end to end due to space considerations at the EOC site, so we had to compromise on that, which makes the other factors very important. I need to point out that as an experiment, a 2nd station used an antenna on 20 meters separated from the main 20 meters, and we were able to operate one on CW (K3) at the same time as the other station (Icom) used digital and SSB modes. We had some mutual interference, but it was minimal. The K3 did not interfere much with the Icom due to the K3's low phase noise, but the Icom did raise the background noise level on the K3. 73, Don W3FPR __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Center-fed antennas
Fair enough, but it kinda goes without saying that in a group FD with 1 station per band they'll use resonant, single-band antennas. If this is our best argument against the 'multiband dipole', then that antenna still holds its own pretty well in a multitude of other situations. I have always found a deep resistance and opposition to this antenna. Whether it's an unwillingness to use antenna tuners, which many hams have, or an undue fear of noise, which some hams have, or a belief that open-wire line is noisier/weirder/harder/impossible-to-go-through-walls, which many hams believe, the visceral reaction against this antenna always amazes and baffles me. Please forgive my belligerence... the Dodgers lost and I've been in a sour mood all day. Al W6LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Center-fed antennas
Bob, Bandpass filters at each station will help a lot, but they do not have infinite out of band rejection. There is still a huge benefit with single band antennas. My club uses both. Last Field Day (3F operation) one station got on the air with a multiband vertical, and all other operators jumped on that operator to shut him down quickly! The multi-band antenna radiated harmonics of the radio. Even though the transmitter met the -43 dB harmonic required by the FCC, the proximity of the multiband antenna to other antennas caused problems (that station was not using a bandpass filter). So for Field Day multi-station operation, single band antennas, bandpass filters and transmitters with low phase noise are important. We were not able to orient the antennas end to end due to space considerations at the EOC site, so we had to compromise on that, which makes the other factors very important. I need to point out that as an experiment, a 2nd station used an antenna on 20 meters separated from the main 20 meters, and we were able to operate one on CW (K3) at the same time as the other station (Icom) used digital and SSB modes. We had some mutual interference, but it was minimal. The K3 did not interfere much with the Icom due to the K3's low phase noise, but the Icom did raise the background noise level on the K3. 73, Don W3FPR On 10/10/2019 7:12 PM, Bob McGraw K4TAX wrote: I thought a Band Pass Filter at each station resolved that issue. 73 Bob, K4TAX On 10/10/2019 5:27 PM, Ken G Kopp wrote: Well-said, Don. 73! Ken Kopp - K0PP On Thu, Oct 10, 2019, 16:23 Don Wilhelm wrote: All this talk of multi-band antennas for Field Day ignores the problem of multi-station Field Day operation. There is sufficient pickup of one transmitter's energy on the antenna being used by a receiver on another band. For that reason, my club has banned the use of multiband antennas for Field Day operation. For a single station Field Day operation, the multiband antennas are great. 73, Don W3FPR __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Center-fed antennas
I have over 200 countries on a similar antenna, though I had to use another tuner than the KAT500, for 160M. Average height was about 35'. Just keep the coax short, like under 10' and as much center fed wire as you can put in the air, it'll play. It won't rock your world, it'll make you work for some of the DX, but that teaches patience and operating technique, still win-win. Rick nhc On 10/10/2019 1:56 PM, Lyn Norstad wrote: I'm having great success with a horizontal center-fed "dipole" that has been sized (360 feet long) to be an Extended Double Zepp (4.7 dbi gain) and cut for the low end of 80 meters. I feed it with 600 ohm "True" Ladder Line from a Balun Designs Hybrid Balun (1:1 Current and 4:1 Voltage all in one case). A short run of coax from the balun to my KAT500, and I am in business at any frequency on 160 - 6 meters. It's oriented to be an effective NVIS radiator in a N-S pattern on 80m, by design, and to have major lobes on the other bands in other directions - also by design. For me, it's the most efficient and effective way to utilize our lot space (400 feet clear) and still be "under the radar" in our HOA. Birds seem to like it, and I find that it seems to be especially attractive to Hummingbirds, my XYL's favorites. A win-win, in my book. 73 Lyn, WØLEN -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Al Lorona Sent: Thursday, October 10, 2019 3:25 PM To: elecraft@mailman.qth.net; David Gilbert Subject: [Elecraft] Center-fed antennas My experience with single vertical or sloping wires is exactly the same as AB7E's. I have, over almost twice as many Field Days as Dave, come to a similar conclusion, with the slight difference being my preference for an "all-band dipole" fed with balanced line. This obviates the balun and reduces feedline loss to negligible, so obviously I am maximizing efficiency at the expense of any other possible advantage. (I can usually hear much better than I can be heard... so thus far this has been a valid decision.) To sum up what I and what I think Dave are saying, you can't beat a horizontal, center-fed wire up as high as you can get it. Its simplicity, the flexibility it gives you to QSY (with a good tuner), and its high efficiency are almost unbeatable. As a side note, the center-fed horizontal wire I have used here at home is totally non-resonant. I don't even know how long it is. Once you give up the obsession with resonant antenna length, you gain a huge freedom of choice. In the bottom of the sunspot cycle, these advantages are somewhat reduced because an op, especially on Field Day, might opt to forget about any band higher than 20 meters -- and these days even 20 is questionable. This means you can probably make do with coaxial cable and a balun for operation on 2 or 3 bands but the general idea still holds. Al W6LX Yes, a center fed normal dipole with the middle (high current portion) higher off the ground (say 50 feet for 40m) and a common mode choke at the feedpoint would almost assuredly perform better. 73, Dave AB7E __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to l...@lnainc.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to wa6...@gmail.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Center-fed antennas
I thought a Band Pass Filter at each station resolved that issue. 73 Bob, K4TAX On 10/10/2019 5:27 PM, Ken G Kopp wrote: Well-said, Don. 73! Ken Kopp - K0PP On Thu, Oct 10, 2019, 16:23 Don Wilhelm wrote: All this talk of multi-band antennas for Field Day ignores the problem of multi-station Field Day operation. There is sufficient pickup of one transmitter's energy on the antenna being used by a receiver on another band. For that reason, my club has banned the use of multiband antennas for Field Day operation. For a single station Field Day operation, the multiband antennas are great. 73, Don W3FPR On 10/10/2019 5:32 PM, David Lee / Seatools wrote: On Thu, Oct 10, 2019 at 2:06 PM Fred Jensen wrote: Yes, however ... a center-fed dipole long enough to be moderately close to a half-wave at 40 will develop a serious case of acute lobe-itis when operated at higher frequencies, squirting your RF in a variety of directions, many of which may not be productive for your intended objective. Try, as many have over the years, to design the "magic antenna" that is very small, provides a 1:1 match on all bands, easily installed, and exhibits good gain, your effort will inevitably fail. As JC Maxwell is reported to have said, "Physics is physics, the rules are unbreakable." A log-periodic will give very modest gain over an octave or more, however LP's hardly fall into the Field Antenna class. [:-) 73, Fred ["Skip"] K6DGW Sparks NV DM09dn Washoe County On 10/10/2019 1:24 PM, Al Lorona wrote: My experience with single vertical or sloping wires is exactly the same as AB7E's. I have, over almost twice as many Field Days as Dave, come to a similar conclusion, with the slight difference being my preference for an "all-band dipole" fed with balanced line. This obviates the balun and reduces feedline loss to negligible, so obviously I am maximizing efficiency at the expense of any other possible advantage. (I can usually hear much better than I can be heard... so thus far this has been a valid decision.) To sum up what I and what I think Dave are saying, you can't beat a horizontal, center-fed wire up as high as you can get it. Its simplicity, the flexibility it gives you to QSY (with a good tuner), and its high efficiency are almost unbeatable. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to kengk...@gmail.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to rmcg...@blomand.net __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] Center-fed antennas
Well-said, Don. 73! Ken Kopp - K0PP On Thu, Oct 10, 2019, 16:23 Don Wilhelm wrote: > All this talk of multi-band antennas for Field Day ignores the problem > of multi-station Field Day operation. > There is sufficient pickup of one transmitter's energy on the antenna > being used by a receiver on another band. > For that reason, my club has banned the use of multiband antennas for > Field Day operation. > > For a single station Field Day operation, the multiband antennas are great. > > 73, > Don W3FPR > > On 10/10/2019 5:32 PM, David Lee / Seatools wrote: > > On Thu, Oct 10, 2019 at 2:06 PM Fred Jensen wrote: > > > >> Yes, however ... a center-fed dipole long enough to be moderately close > >> to a half-wave at 40 will develop a serious case of acute lobe-itis when > >> operated at higher frequencies, squirting your RF in a variety of > >> directions, many of which may not be productive for your intended > >> objective. Try, as many have over the years, to design the "magic > >> antenna" that is very small, provides a 1:1 match on all bands, easily > >> installed, and exhibits good gain, your effort will inevitably fail. As > >> JC Maxwell is reported to have said, "Physics is physics, the rules are > >> unbreakable." A log-periodic will give very modest gain over an octave > >> or more, however LP's hardly fall into the Field Antenna class. [:-) > >> > >> 73, > >> Fred ["Skip"] K6DGW > >> Sparks NV DM09dn > >> Washoe County > >> > >> On 10/10/2019 1:24 PM, Al Lorona wrote: > >>> My experience with single vertical or sloping wires is exactly the same > >> as AB7E's. I have, over almost twice as many Field Days as Dave, come > to a > >> similar conclusion, with the slight difference being my preference for > an > >> "all-band dipole" fed with balanced line. This obviates the balun and > >> reduces feedline loss to negligible, so obviously I am maximizing > >> efficiency at the expense of any other possible advantage. (I can > usually > >> hear much better than I can be heard... so thus far this has been a > valid > >> decision.) > >>> > >>> To sum up what I and what I think Dave are saying, you can't beat a > >> horizontal, center-fed wire up as high as you can get it. Its > simplicity, > >> the flexibility it gives you to QSY (with a good tuner), and its high > >> efficiency are almost unbeatable. > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to kengk...@gmail.com > __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Center-fed antennas
Precisely because of this objection and countless others, is why I expressly stated, "...at the expense of any other possible advantage." I think we all understand that there's no magic antenna. The 'magic' of the antenna we're discussing here is simplicity, all-frequency operation, and high efficiency. No other magical claims are being made. Al W6LX >Yes, however ... a center-fed dipole long enough to be moderately close >to a half-wave at 40 will develop a serious case of acute lobe-itis when >operated at higher frequencies __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Center-fed antennas
All this talk of multi-band antennas for Field Day ignores the problem of multi-station Field Day operation. There is sufficient pickup of one transmitter's energy on the antenna being used by a receiver on another band. For that reason, my club has banned the use of multiband antennas for Field Day operation. For a single station Field Day operation, the multiband antennas are great. 73, Don W3FPR On 10/10/2019 5:32 PM, David Lee / Seatools wrote: On Thu, Oct 10, 2019 at 2:06 PM Fred Jensen wrote: Yes, however ... a center-fed dipole long enough to be moderately close to a half-wave at 40 will develop a serious case of acute lobe-itis when operated at higher frequencies, squirting your RF in a variety of directions, many of which may not be productive for your intended objective. Try, as many have over the years, to design the "magic antenna" that is very small, provides a 1:1 match on all bands, easily installed, and exhibits good gain, your effort will inevitably fail. As JC Maxwell is reported to have said, "Physics is physics, the rules are unbreakable." A log-periodic will give very modest gain over an octave or more, however LP's hardly fall into the Field Antenna class. [:-) 73, Fred ["Skip"] K6DGW Sparks NV DM09dn Washoe County On 10/10/2019 1:24 PM, Al Lorona wrote: My experience with single vertical or sloping wires is exactly the same as AB7E's. I have, over almost twice as many Field Days as Dave, come to a similar conclusion, with the slight difference being my preference for an "all-band dipole" fed with balanced line. This obviates the balun and reduces feedline loss to negligible, so obviously I am maximizing efficiency at the expense of any other possible advantage. (I can usually hear much better than I can be heard... so thus far this has been a valid decision.) To sum up what I and what I think Dave are saying, you can't beat a horizontal, center-fed wire up as high as you can get it. Its simplicity, the flexibility it gives you to QSY (with a good tuner), and its high efficiency are almost unbeatable. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Center-fed antennas
On Thu, Oct 10, 2019 at 2:06 PM Fred Jensen wrote: > Yes, however ... a center-fed dipole long enough to be moderately close > to a half-wave at 40 will develop a serious case of acute lobe-itis when > operated at higher frequencies, squirting your RF in a variety of > directions, many of which may not be productive for your intended > objective. Try, as many have over the years, to design the "magic > antenna" that is very small, provides a 1:1 match on all bands, easily > installed, and exhibits good gain, your effort will inevitably fail. As > JC Maxwell is reported to have said, "Physics is physics, the rules are > unbreakable." A log-periodic will give very modest gain over an octave > or more, however LP's hardly fall into the Field Antenna class. [:-) > > 73, > Fred ["Skip"] K6DGW > Sparks NV DM09dn > Washoe County > > On 10/10/2019 1:24 PM, Al Lorona wrote: > > My experience with single vertical or sloping wires is exactly the same > as AB7E's. I have, over almost twice as many Field Days as Dave, come to a > similar conclusion, with the slight difference being my preference for an > "all-band dipole" fed with balanced line. This obviates the balun and > reduces feedline loss to negligible, so obviously I am maximizing > efficiency at the expense of any other possible advantage. (I can usually > hear much better than I can be heard... so thus far this has been a valid > decision.) > > > > To sum up what I and what I think Dave are saying, you can't beat a > horizontal, center-fed wire up as high as you can get it. Its simplicity, > the flexibility it gives you to QSY (with a good tuner), and its high > efficiency are almost unbeatable. > > > > As a side note, the center-fed horizontal wire I have used here at home > is totally non-resonant. I don't even know how long it is. Once you give up > the obsession with resonant antenna length, you gain a huge freedom of > choice. > > > > In the bottom of the sunspot cycle, these advantages are somewhat > reduced because an op, especially on Field Day, might opt to forget about > any band higher than 20 meters -- and these days even 20 is questionable. > This means you can probably make do with coaxial cable and a balun for > operation on 2 or 3 bands but the general idea still holds. > > > > Al W6LX > > > > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to seatools.w...@gmail.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Center-fed antennas
Yes, however ... a center-fed dipole long enough to be moderately close to a half-wave at 40 will develop a serious case of acute lobe-itis when operated at higher frequencies, squirting your RF in a variety of directions, many of which may not be productive for your intended objective. Try, as many have over the years, to design the "magic antenna" that is very small, provides a 1:1 match on all bands, easily installed, and exhibits good gain, your effort will inevitably fail. As JC Maxwell is reported to have said, "Physics is physics, the rules are unbreakable." A log-periodic will give very modest gain over an octave or more, however LP's hardly fall into the Field Antenna class. [:-) 73, Fred ["Skip"] K6DGW Sparks NV DM09dn Washoe County On 10/10/2019 1:24 PM, Al Lorona wrote: My experience with single vertical or sloping wires is exactly the same as AB7E's. I have, over almost twice as many Field Days as Dave, come to a similar conclusion, with the slight difference being my preference for an "all-band dipole" fed with balanced line. This obviates the balun and reduces feedline loss to negligible, so obviously I am maximizing efficiency at the expense of any other possible advantage. (I can usually hear much better than I can be heard... so thus far this has been a valid decision.) To sum up what I and what I think Dave are saying, you can't beat a horizontal, center-fed wire up as high as you can get it. Its simplicity, the flexibility it gives you to QSY (with a good tuner), and its high efficiency are almost unbeatable. As a side note, the center-fed horizontal wire I have used here at home is totally non-resonant. I don't even know how long it is. Once you give up the obsession with resonant antenna length, you gain a huge freedom of choice. In the bottom of the sunspot cycle, these advantages are somewhat reduced because an op, especially on Field Day, might opt to forget about any band higher than 20 meters -- and these days even 20 is questionable. This means you can probably make do with coaxial cable and a balun for operation on 2 or 3 bands but the general idea still holds. Al W6LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Center-fed antennas
I'm having great success with a horizontal center-fed "dipole" that has been sized (360 feet long) to be an Extended Double Zepp (4.7 dbi gain) and cut for the low end of 80 meters. I feed it with 600 ohm "True" Ladder Line from a Balun Designs Hybrid Balun (1:1 Current and 4:1 Voltage all in one case). A short run of coax from the balun to my KAT500, and I am in business at any frequency on 160 - 6 meters. It's oriented to be an effective NVIS radiator in a N-S pattern on 80m, by design, and to have major lobes on the other bands in other directions - also by design. For me, it's the most efficient and effective way to utilize our lot space (400 feet clear) and still be "under the radar" in our HOA. Birds seem to like it, and I find that it seems to be especially attractive to Hummingbirds, my XYL's favorites. A win-win, in my book. 73 Lyn, WØLEN -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Al Lorona Sent: Thursday, October 10, 2019 3:25 PM To: elecraft@mailman.qth.net; David Gilbert Subject: [Elecraft] Center-fed antennas My experience with single vertical or sloping wires is exactly the same as AB7E's. I have, over almost twice as many Field Days as Dave, come to a similar conclusion, with the slight difference being my preference for an "all-band dipole" fed with balanced line. This obviates the balun and reduces feedline loss to negligible, so obviously I am maximizing efficiency at the expense of any other possible advantage. (I can usually hear much better than I can be heard... so thus far this has been a valid decision.) To sum up what I and what I think Dave are saying, you can't beat a horizontal, center-fed wire up as high as you can get it. Its simplicity, the flexibility it gives you to QSY (with a good tuner), and its high efficiency are almost unbeatable. As a side note, the center-fed horizontal wire I have used here at home is totally non-resonant. I don't even know how long it is. Once you give up the obsession with resonant antenna length, you gain a huge freedom of choice. In the bottom of the sunspot cycle, these advantages are somewhat reduced because an op, especially on Field Day, might opt to forget about any band higher than 20 meters -- and these days even 20 is questionable. This means you can probably make do with coaxial cable and a balun for operation on 2 or 3 bands but the general idea still holds. Al W6LX >Yes, a center fed normal dipole with the middle (high current portion) >higher off the ground (say 50 feet for 40m) and a common mode choke at >the feedpoint would almost assuredly perform better. > >73, >Dave AB7E __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to l...@lnainc.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] Center-fed antennas
My experience with single vertical or sloping wires is exactly the same as AB7E's. I have, over almost twice as many Field Days as Dave, come to a similar conclusion, with the slight difference being my preference for an "all-band dipole" fed with balanced line. This obviates the balun and reduces feedline loss to negligible, so obviously I am maximizing efficiency at the expense of any other possible advantage. (I can usually hear much better than I can be heard... so thus far this has been a valid decision.) To sum up what I and what I think Dave are saying, you can't beat a horizontal, center-fed wire up as high as you can get it. Its simplicity, the flexibility it gives you to QSY (with a good tuner), and its high efficiency are almost unbeatable. As a side note, the center-fed horizontal wire I have used here at home is totally non-resonant. I don't even know how long it is. Once you give up the obsession with resonant antenna length, you gain a huge freedom of choice. In the bottom of the sunspot cycle, these advantages are somewhat reduced because an op, especially on Field Day, might opt to forget about any band higher than 20 meters -- and these days even 20 is questionable. This means you can probably make do with coaxial cable and a balun for operation on 2 or 3 bands but the general idea still holds. Al W6LX >Yes, a center fed normal dipole with the middle (high current portion) >higher off the ground (say 50 feet for 40m) and a common mode choke at >the feedpoint would almost assuredly perform better. > >73, >Dave AB7E __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
