You will have some loss in the coax, so I would shorten it. Did you actually check to see how the antenna worked (not the SWR)?
I've had the KH1 for about a week now and have been pleased, amazed even, at how well the whip works, and my understanding is that it's basically the same antenna as the AX1 - I've only used it on 20, 17, and 15 so far as I don't have a 40m coil. But check RBN for my call - all in the past week has been with the KH1, and all but the last few spots were using the built-in whip. GL & 73 de Lee, AA4GA Lee, AA4GA On Wed, Sep 25, 2024, 6:18 PM James Bennett via Elecraft < elecraft@mailman.qth.net> wrote: > Several months ago I started building up a POTA station, including a KX3 > (with internal tuner), the AX1 Dual Band Antenna, the AXE1 40 Meter > Extender, and the AXT1 Tripod Adapter. This afternoon I finally got the > time to see how this antenna plays. I was a bit disappointed. Here is the > setup: > > KX3 (with internal tuner), 25 feet of RG-316 with ferrites on the radio > end, five foot tall carbon fiber tripod sitting in the middle of my back > yard; no other resonant antennas on the property. > > The KX3 / ATU WAS able to find a match to the antenna on all the bands. At > first I thought that was great. But being a bit curious, I disconnected the > coax and hooked up my Rig Expert AA-55 Zoom. Ughhh. On 40 meters, with the > long radial attached and suspended 4-5 feet above the yard, the antennas > was resonant at 7.574 MHz - that’s a tad more then the +- 200 KHz stated in > the specs. And quite ugly for where I wanted to operate: 7.052 KHz. So, I > added the shorter radial, also up above the ground, going a different > direction. NO CHANGE to the resonant frequency. Yes, I did have the AXE1 > installed, and yes I had the switch set to the “20m” position. > > OK, let’s give 30 meters a try. I set the switch to “17m”, and the Rig > Expert to 10.116 +- 5 MHz. Yikes - the thing was resonant at 8.070 MHz - > very long way from 10.116. Adding the short radial changed the SWR at that > frequency from 1.46:1 down to 1.33:1 but no change to resonant frequency. > > 20 meters didn’t fare much better. I set the switch to “20m”, removed the > AXE1, and connected only the short radial. Minimum SWR of 1.34:1 was seen > at 15.330 MHz. At my desired operating frequency of 14.052, the SWR was > 6.9:1. Not a very good SWR but one that the ATU can easily handle. > > 17 meters was just as bad. With the short radial it was resonant at 19.780 > with an SWR of 1.15:1; at 18.116 it showed 6.83:1 SWR. Again, something the > ATU can deal with, but….. > > While I understand that this is a compromise antenna and it isn’t going to > be spot on on every band, I’m a bit frustrated in what I’m seeing here. > With five watts output into those kind of SWRs, I’m sure I’m loosing quite > a bit of my power in heating the coax and the modules in the ATU. I > hesitate to go out on a maiden POTA activation with an antenna showing > close to 7:1 SWR at my operating frequencies, even though the ATU > “corrects” that. > > Any suggestions here? Is this “normal” for the AX1 and AXE1? > > Jim Bennett / K7TXA > Eagle, ID > > SKCC #10447T > B.U.G. #301 > > > > > > > > ______________________________________________________________ > 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 lee.hi...@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
