After the ice storm of 2009, I'm looking for an new antenna. I've
been considering the 43' verticals by DXE,HyGain and MFJ. But I'm not sure if my K2 tuner will have the range needed. The DXE site has a warning about internal tuners. Anyone using a K2 and a 43' vertical ? how's it play ? Thanks in Advance - Jim (WB1DOG) ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
I use a Zero Five 43' vertical with my K3. Not sure if the K2 tuner is
equivalent to the K3, but if it is, it should work well. As an example, I worked K5D on 160 through 20m with my Zero Five 43' vertical @ 100w. -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of James Apple Sent: Sunday, March 15, 2009 8:27 AM To: [hidden email] Subject: [Elecraft] 43' Vertical and the K2 tuner After the ice storm of 2009, I'm looking for an new antenna. I've been considering the 43' verticals by DXE,HyGain and MFJ. But I'm not sure if my K2 tuner will have the range needed. The DXE site has a warning about internal tuners. Anyone using a K2 and a 43' vertical ? how's it play ? Thanks in Advance - Jim (WB1DOG) ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
In reply to this post by James Apple
Good Morning Jim ...
The internal K2 tuner should have the range to match the 43 ft vertical. It is a wide-range tuner as opposed to the internal tuners on many rigs which are only good for tweaking antennas that are near resonance. You will, of course, have feedline losses due to high SWR with this system which can be noticeable on some bands. You will want to use low loss feedline and a proper current choke at the feedpoint. The resulting performance will depend heavily on the radial system used, and I would recommend a minimum of 32 untuned radials. Given attention to these details, you can expect good DX performance on 20, 30, 40 and 80 meters. On 17 meters and above the radiation angle will become higher than optimal for DX. The feedline loss issues can be resolved by using a remote tuner at the feedpoint. I'm doing this here using a CG-3000 tuner from Array Solutions. Works well with my K3, and I'm pleased with the performance of the antenna after installation of an adequate radial system. 73 Craig AC0DS ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
In reply to this post by James Apple
If you use a rather long coax feedline, the K2 tuner might match it. Reason:
The coax acts to reduce the "apparant" SWR by inducing considerable power loss. The 43' vertical is recent fad and it makes no sense at all. Virtually any trapped multiband vertical should easily outperform it. If you want to find out how it works, just run 43' for wire up a pole or a tree limb and see. Do this before investing $300 in a stick of aluminum. Also, you may be subjecting the little components in your K2's tuner to high currents when attempting to match that 43' stick on 80 and 160 meters. Impedances would be insanely low! Recommend using a remote tuner at the antenna's base, forget the so called balun/unun or a different antenna. 73 Steve Ellington [hidden email] ----- Original Message ----- From: "James Apple" <[hidden email]> To: <[hidden email]> Sent: Sunday, March 15, 2009 9:26 AM Subject: [Elecraft] 43' Vertical and the K2 tuner > After the ice storm of 2009, I'm looking for an new antenna. I've > been considering the 43' verticals by DXE,HyGain and MFJ. But I'm not > sure if my K2 tuner will have the range needed. The DXE site has a > warning about internal tuners. Anyone using a K2 and a 43' vertical ? > how's it play ? > > Thanks in Advance > > - Jim (WB1DOG) > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html -------------------------------------------------------------------------------- No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.0.237 / Virus Database: 270.11.13/2001 - Release Date: 03/14/09 06:54:00 ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
> The 43' vertical is recent fad and it makes no sense at all. Virtually
> any trapped multiband vertical should easily outperform it. Steve, I thought the same until I read this: http://vk1od.net/antenna/multibandunloadedvertical/ According to the author, the so-called "magic" of the 43-foot length is that radiation resistance remains quite high across the HF spectrum and thus, system losses are minimized. Compared to a 33-foot vertical, system losses are much lower across the spectrum. But to your point, a trapped multi-band vertical can offer similar performance. Personally, I think the negativity associated with trap loss in multi-band antennas is grossly overblown. Other systematic losses mask what little loss exists in most trapped antenna designs. Anyway, not sure how valid all this data really is, but the data presented is interesting Paul, W9AC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
But note that for the 43' mast they use an autotuner located at the
base of the mast, no coax losses involved. For the 33' mast they use ~50' of various pieces of coax with the associated losses. This a very biased comparison. If you are going to use a non-trapped, and hence non-resonant, vertical it is best to put the tuner at the base of the mast. Otherwise the coax losses will eat up a fair amount of the available power, even for a 43' mast (although they don't tell you this). 73 de dave ab9ca/4 Paul Christensen wrote: >> The 43' vertical is recent fad and it makes no sense at all. Virtually >> any trapped multiband vertical should easily outperform it. > > Steve, > > I thought the same until I read this: > > http://vk1od.net/antenna/multibandunloadedvertical/ > > According to the author, the so-called "magic" of the 43-foot length is that > radiation resistance remains quite high across the HF spectrum and thus, > system losses are minimized. Compared to a 33-foot vertical, system losses > are much lower across the spectrum. > > But to your point, a trapped multi-band vertical can offer similar > performance. Personally, I think the negativity associated with trap loss > in multi-band antennas is grossly overblown. Other systematic losses mask > what little loss exists in most trapped antenna designs. > > Anyway, not sure how valid all this data really is, but the data presented > is interesting > > Paul, W9AC > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > > Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
In reply to this post by P.B. Christensen
Back to the original question about using the K2's or K3's tuner on this
antenna....Figure 4. in that link shows the impedance of the antenna to be less than 10 ohms below 5 mHz and around 1 ohm on 160M. Factor the 1:4 balun in and that divides the Z by 4. So we end up with an impedance of less than 2 ohms presented to the K2's tuner. Open the windows and let the smoke out please. Steve Ellington [hidden email] ----- Original Message ----- From: "Paul Christensen" <[hidden email]> To: "Steve Ellington" <[hidden email]>; <[hidden email]> Sent: Sunday, March 15, 2009 10:07 AM Subject: Re: [Elecraft] 43' Vertical and the K2 tuner >> The 43' vertical is recent fad and it makes no sense at all. Virtually >> any trapped multiband vertical should easily outperform it. > > Steve, > > I thought the same until I read this: > > http://vk1od.net/antenna/multibandunloadedvertical/ > > According to the author, the so-called "magic" of the 43-foot length is > that > radiation resistance remains quite high across the HF spectrum and thus, > system losses are minimized. Compared to a 33-foot vertical, system > losses > are much lower across the spectrum. > > But to your point, a trapped multi-band vertical can offer similar > performance. Personally, I think the negativity associated with trap loss > in multi-band antennas is grossly overblown. Other systematic losses mask > what little loss exists in most trapped antenna designs. > > Anyway, not sure how valid all this data really is, but the data presented > is interesting > > Paul, W9AC > -------------------------------------------------------------------------------- No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.0.237 / Virus Database: 270.11.13/2001 - Release Date: 03/14/09 06:54:00 ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
Steve Ellington wrote:
> Back to the original question about using the K2's or K3's tuner on this > antenna....Figure 4. in that link shows the impedance of the antenna to be > less than 10 ohms below 5 mHz and around 1 ohm on 160M. Factor the 1:4 > balun in and that divides the Z by 4. So we end up with an impedance of less > than 2 ohms presented to the K2's tuner. Open the windows and let the smoke > out please. I modeled a plain 43' vertical in EZNEC. Fed with 50-ohm line, the SWR on 40 meters is a bit less than 10:1; on 80 it's nearly 100:1. (11.1 - j232). It would be a dummy load on 80. Some of these antennas (like the Array Solutions mentioned) include baluns or transformers. My guess is that the large amount of reactance would increase losses in such a device. A tuner at the base would be the way to go. But keep in mind that you still need a good local ground system as well as decent ground conductivity within a few wavelengths for reasonable performance. -- 73, Vic, K2VCO Fresno CA http://www.qsl.net/k2vco ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
In reply to this post by P.B. Christensen
CONTENTS DELETED
The author has deleted this message.
|
In reply to this post by James Apple
We just had a heated exchange about these antennas on another reflector.
Keep in mind that it is a compromise antenna. 43 feet is really not magical to any band that I know of. You still need a good radial system etc. >From what I have read the tuner at the base would be much more efficient and use a good quality coax. I would be curious to see how a BigIR or even a Hy-tower compared to the 43 ft verticals. I was surprised to read that W5OV was able to match it with the K3 tuner. I think that speaks volumes for the tuner in the K3. I will have to play with my tuner a bit more. Most of my antennas have good swr except for the 40m beam in the extreme lower cw sections and the K3 tunes this fine but we are talking about 2 to 2.5 to 1 max, not 100:1 "A slip of the foot you may soon recover, but a slip of the tongue you may never get over." Ben Franklin -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of James Apple Sent: Sunday, March 15, 2009 7:27 AM To: [hidden email] Subject: [Elecraft] 43' Vertical and the K2 tuner After the ice storm of 2009, I'm looking for an new antenna. I've been considering the 43' verticals by DXE,HyGain and MFJ. But I'm not sure if my K2 tuner will have the range needed. The DXE site has a warning about internal tuners. Anyone using a K2 and a 43' vertical ? how's it play ? Thanks in Advance - Jim (WB1DOG) ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
In reply to this post by P.B. Christensen
Paul and All,
This is very interesting! Thanks for bringing that article by VK1OD to our attention. I think I agree with you about trap losses. I have used a Cushcraft R7, and now an R8, for years with surprisingly good results. What appealed to me about both of these models is that they emulate a 1/2 wave antenna, thus making radials more or less unnecessary. These antennas only cover 40 and up however. What now intrigues me about the 43 ft. antenna is connected to some comments made to me by Jim Duffey, KK6MC ("Dr. Megacycle") when he visited here some time ago. I think most of you are familiar with Jim, and respect (as I do) his technical expertise. Anyway, Jim suggested that I might be even better off with a 22 ft. vertical on my roof, with as many radials as I could reasonably lay out. He said I should also use a remote tuner and balanced feedline. Jim felt it would perform adequately on 40 meters, and better as you go up. I believe he said the "magic" about 22 feet was to try and keep the radiation angle from getting too high on the higher bands. So, now I'm wondering if a 43 ft. antenna would bring 80 meters, and apparently 160 meters, into play under more or less the same concept that Jim was espousing. He didn't really mention that the 22 ft. version might get you on 80, so maybe not, but the mathematical relationship sure has me wondering. Probably I'm extrapolating his comments incorrectly. I think Jim does monitor this reflector, so maybe he will jump in and make some comments. I will probably pass that article to him though, and see if I can prod him for some insight. By the way, I'm guessing that if you could roof mount, or otherwise elevate the 43 foot version, you might not have to worry quite so much about having so many radials. Anyway, this motivates me to do a little digging! Dave W7AQK ----- Original Message ----- From: "Paul Christensen" <[hidden email]> To: "Steve Ellington" <[hidden email]>; <[hidden email]> Sent: Sunday, March 15, 2009 7:07 AM Subject: Re: [Elecraft] 43' Vertical and the K2 tuner >> The 43' vertical is recent fad and it makes no sense at all. Virtually >> any trapped multiband vertical should easily outperform it. > > Steve, > > I thought the same until I read this: > > http://vk1od.net/antenna/multibandunloadedvertical/ > > According to the author, the so-called "magic" of the 43-foot length is > that > radiation resistance remains quite high across the HF spectrum and thus, > system losses are minimized. Compared to a 33-foot vertical, system > losses > are much lower across the spectrum. > > But to your point, a trapped multi-band vertical can offer similar > performance. Personally, I think the negativity associated with trap loss > in multi-band antennas is grossly overblown. Other systematic losses mask > what little loss exists in most trapped antenna designs. > > Anyway, not sure how valid all this data really is, but the data presented > is interesting > > Paul, W9AC > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
In reply to this post by w0mu
I used a 40' self-supporting Premax shipboard whip on our
travel trailer for six years. It was fed with an Icom AH-4 with 6" of connecting wire between the tuner and the whip. I think it worked well. It was -not- a good performer on 80M, as one would expect. I wouldn't consider feeding this antenna with a lengthy run of coax. I -do- have extensive bonding of the ground system to the metal trailer's body and frame and also uncoiled a number of radials "into the bushes" when we were parked. I used these same whips in the 3 mHz frequency range on small ocean survey vessels, but hasten to point out that this approached an ideal situation ... a vertical over salt water. (:-) Again, this antenna was fed with a tuner immediately beside the base of the whip. I now use a modified High Sierra "screwdriver" antenna on the trailer, mostly to gain acceptable performance on 80M. I more than doubled the length of the base to coil length to improve the efficiency. 73! ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
In reply to this post by w0mu
Mike and All,
I'm not all that surprised that W5OV was able to get a match using his K3, although I'm not sure exactly how severe the mismatch is. It has to be pretty far off though. Using my K3, with its built-in ATU, I am able to get a 1:1 match on 80 meters using my R8 vertical, which isn't supposed to go lower than 40 meters. I can also get a match that is better than 2:1 on 160. Obviously though, the efficiency of this antenna on those bands is pretty lousy. I really don't operate on 160, except I did work VP6DX on both SSB and CW with this arrangement. Their beverages did all the work though I'm sure. Nevertheless, the K3's ATU is very good! I haven't tried the same test with my K2 and it's built-in ATU, but that tuner is very good also. I just don't know if it's quite as good as the K3's. The ATU in my Orion II will also match the R8 on 80 meters, but just about every other rig I own, or have owned, with a built in ATU, would not come close to doing this. I have a Kenwood TS-480 and a Yaesu FT-1000 Mark V, neither of which could do that. The Mark V won't even allow me to cover all of 40 meters, but the K3 does it with ease. Having said all of this, I'd be very cautious about big excursions with the K3 or K2 built-in ATU's. I'd sure turn the power down a lot before even trying. Clearly though, not all built-in ATU's are equal! Dave W7AQK ----- Original Message ----- From: "W0MU Mike Fatchett" <[hidden email]> To: "'James Apple'" <[hidden email]>; <[hidden email]> Sent: Sunday, March 15, 2009 9:16 AM Subject: Re: [Elecraft] 43' Vertical and the K2 tuner > We just had a heated exchange about these antennas on another reflector. > > Keep in mind that it is a compromise antenna. 43 feet is really not > magical > to any band that I know of. You still need a good radial system etc. > >>From what I have read the tuner at the base would be much more efficient >>and > use a good quality coax. > > I would be curious to see how a BigIR or even a Hy-tower compared to the > 43 > ft verticals. > > I was surprised to read that W5OV was able to match it with the K3 tuner. > I > think that speaks volumes for the tuner in the K3. I will have to play > with > my tuner a bit more. Most of my antennas have good swr except for the 40m > beam in the extreme lower cw sections and the K3 tunes this fine but we > are > talking about 2 to 2.5 to 1 max, not 100:1 > > > > > "A slip of the foot you may soon recover, but a slip of the tongue you may > never get over." Ben Franklin > -----Original Message----- > From: [hidden email] > [mailto:[hidden email]] On Behalf Of James Apple > Sent: Sunday, March 15, 2009 7:27 AM > To: [hidden email] > Subject: [Elecraft] 43' Vertical and the K2 tuner > > After the ice storm of 2009, I'm looking for an new antenna. I've been > considering the 43' verticals by DXE,HyGain and MFJ. But I'm not sure if > my > K2 tuner will have the range needed. The DXE site has a warning about > internal tuners. Anyone using a K2 and a 43' vertical ? > how's it play ? > > Thanks in Advance > > - Jim (WB1DOG) > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
In reply to this post by w7aqk
Dave,
If you look at the LB Cebik information, he has long recommended 44 foot dipoles as a back-up antenna for 40 through 10 meters and 88 foot dipoles for 80 through 20. The main reason for his recommendation is that the radiation pattern does not break up into lobes over that range of frequencies, and all the radiation is broadside to the antenna wire. Now, take that dipole and stand it on end - the radiation pattern will be low to the earth. As a second step, remove the lower portion of the antenna and install radials (22 or 44 ft long) to balance out the vertical section. If the radials are run in opposing directions, any radiation from them will cancel leaving all the radiated power from the vertical element, and it will be at a low angle when operated within the frequency range that keeps the radiation pattern in single lobe (below 10m for the 22 ft vertical and below 20m for the 44 ft vertical). If the vertical element is mounted well above the ground, 4 radials (2 pair oriented in opposing directions) should be sufficient, but if ground mounted, a lot of radials are needed to form a ground screen. An antenna of this nature will not have an impedance suitable for feeding with coax. A remote auto-tuner or an L section designed for each band will be needed at the base to provide a suitable match or the coax. If the feedpoint is transformed to something coax can easily match, most all the power will be delivered to the radiator and the feedline loss will be small, but if directly fed with coax, the losses can be rather high - just how high depends on the feedline length. 73, Don W3FPR dyarnes wrote: > Paul and All, > > This is very interesting! Thanks for bringing that article by VK1OD to our > attention. > > I think I agree with you about trap losses. I have used a Cushcraft R7, and > now an R8, for years with surprisingly good results. What appealed to me > about both of these models is that they emulate a 1/2 wave antenna, thus > making radials more or less unnecessary. These antennas only cover 40 and > up however. > > What now intrigues me about the 43 ft. antenna is connected to some comments > made to me by Jim Duffey, KK6MC ("Dr. Megacycle") when he visited here some > time ago. I think most of you are familiar with Jim, and respect (as I do) > his technical expertise. Anyway, Jim suggested that I might be even better > off with a 22 ft. vertical on my roof, with as many radials as I could > reasonably lay out. He said I should also use a remote tuner and balanced > feedline. Jim felt it would perform adequately on 40 meters, and better as > you go up. I believe he said the "magic" about 22 feet was to try and keep > the radiation angle from getting too high on the higher bands. > > So, now I'm wondering if a 43 ft. antenna would bring 80 meters, and > apparently 160 meters, into play under more or less the same concept that > Jim was espousing. He didn't really mention that the 22 ft. version might > get you on 80, so maybe not, but the mathematical relationship sure has me > wondering. Probably I'm extrapolating his comments incorrectly. > > I think Jim does monitor this reflector, so maybe he will jump in and make > some comments. I will probably pass that article to him though, and see if > I can prod him for some insight. > > By the way, I'm guessing that if you could roof mount, or otherwise elevate > the 43 foot version, you might not have to worry quite so much about having > so many radials. > > Anyway, this motivates me to do a little digging! > > Dave W7AQK > > > ----- Original Message ----- > From: "Paul Christensen" <[hidden email]> > To: "Steve Ellington" <[hidden email]>; <[hidden email]> > Sent: Sunday, March 15, 2009 7:07 AM > Subject: Re: [Elecraft] 43' Vertical and the K2 tuner > > > >>> The 43' vertical is recent fad and it makes no sense at all. Virtually >>> any trapped multiband vertical should easily outperform it. >>> >> Steve, >> >> I thought the same until I read this: >> >> http://vk1od.net/antenna/multibandunloadedvertical/ >> >> According to the author, the so-called "magic" of the 43-foot length is >> that >> radiation resistance remains quite high across the HF spectrum and thus, >> system losses are minimized. Compared to a 33-foot vertical, system >> losses >> are much lower across the spectrum. >> >> But to your point, a trapped multi-band vertical can offer similar >> performance. Personally, I think the negativity associated with trap loss >> in multi-band antennas is grossly overblown. Other systematic losses mask >> what little loss exists in most trapped antenna designs. >> >> Anyway, not sure how valid all this data really is, but the data presented >> is interesting >> >> Paul, W9AC >> > Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
In reply to this post by w7aqk
Pushing 80 meter RF into an R8 could be very bad for the R8. The tuner has
been able to find a match that allows the radio to pump RF into the coax to the antenna but that RF *might* be (mostly) going into the tuning network of the antenna instead of being radiated. Overstress is a definite possibility when doing that so please be careful. Don K7FJ > Using my K3, with its built-in ATU, I am able to get a 1:1 match on 80 > meters using my R8 vertical, which isn't supposed to go lower than 40 > meters. I can also get a match that is better than 2:1 on 160. Obviously > though, the efficiency of this antenna on those bands is pretty lousy. I > really don't operate on 160, except I did work VP6DX on both SSB and CW > with > this arrangement. Their beverages did all the work though I'm sure. > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
In reply to this post by w7aqk
CONTENTS DELETED
The author has deleted this message.
|
In reply to this post by Don Wilhelm-4
I don't have the L and C values for the K2 tuner, but if you want to
see what impedances can be transformed from 50 ohms using the KAT100, you can take a look at these images: http://homepage.mac.com/chen/Technical/Tuner/T3580.jpg http://homepage.mac.com/chen/Technical/Tuner/T14080.jpg http://homepage.mac.com/chen/Technical/Tuner/T28080.jpg The green dots are for transceiver : ( series L : shunt C ) : antenna. The blue dots are for transceiver : ( shunt C : series R ) : antenna. The dots shown are the impedances that the antenna sees if the transceiver's output impedance is 50 ohms. So, antenna impedances that the tuner will tune is just the conjugate of the points that you see on the charts (i.e., just flip the charts upside down). As the file name indicates, they are charts for 3.58 MHz, 14.080 MHz and 28.080 MHz (RTTY frequencies, naturally :-). The application that generates the charts above was originally written to test a Smith Chart library that I wrote for Cocoa. (The library was subsequently used in cocoaNEC and by K1GQ in his cocoaVNA program, an application for the TAPR/Ten-Tec VNA). I'll be glad to make the program available to anyone running Mac OS X 10.4 or newer. You can run the application to generate plots for other frequencies. The Xcode sources are also available in case you have a different set of L and C values (than used in the KAT100) that you want to try out. 73 Chen, W7AY ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
On Mar 15, 2009, at 11:35 AM, Kok Chen wrote: > The blue dots are for transceiver : ( shunt C : series R ) : antenna. Oops, I meant transceiver : ( shunt C : series L ) : antenna. 73 Chen, W7AY ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
In reply to this post by AC7AC
So we've rediscovered the Gotham V80 Vertical!
Steve Ellington [hidden email] ----- Original Message ----- From: "Ron D'Eau Claire" <[hidden email]> To: <[hidden email]> Sent: Sunday, March 15, 2009 2:21 PM Subject: Re: [Elecraft] 43' Vertical and the K2 tuner > Dr. Megacycle has it on the head with the length: 22 feet is 5/8 wave on > 10 > meters. > > Good "commercial" automatic tuners will feed such an antenna all the way > down below 80 meters. The SGC-230 is commonly used on ships feeding a 23 > foot whip all the way down to the emergency SSB frequency at 2182 kHz. > > Many published tests have shown that getting the radials away from the > ground is *very* beneficial and may well outweigh the loss of efficiency > in > reducing the height of the vertical. Back in '87, A. M. Christman, KB8I, > published the results of studies he conducted in the Proceedings of the > Third Annual Review of Progress in Applied Computational Electromagnetics > for the U.S. Naval Postgraduate School, which he later summarized for hams > in an article in the Aug 1988 issue of QST. That article is available to > ARRL members on their web site. It gives numerous examples of the > improvements to be expected as various counterpoise systems are used above > ground. > > Let me point out to anyone interested enough to read my previous post that > I > misspoke. It was kindly brought to my attention by Arnie, PA3A, who > observed > I said a half wave radiator has a high radiation resistance when I meant > to > say it had a high feed point impedance. My conclusion was correct as to > the > benefit of a high feed point impedance, but there's a huge difference > between the resistive value of the feed point impedance and radiation > resistance! > > Ron AC7AC > > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html -------------------------------------------------------------------------------- No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.0.237 / Virus Database: 270.11.13/2001 - Release Date: 03/14/09 06:54:00 ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
All: My K3 TX peak power output is slightly higher on SSB than it is on CW. Is there a way to minimize this difference? Gregg W6IZT ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
Free forum by Nabble | Edit this page |