Hi, If possible raise the antenna higher. Add more radials...
A friend of mine has one of these and we took it out at a portable station using a KX radio. It was 6 feet above the ground, and had 6 radials on it, each around 20 or 30 feet long, sloped heading to the ground. We used WSPR on it during the big eclipse a few years back, and it worked really well, hits all over the world on 20... Radials are the key to making it work better. Being a shortened antenna it will never work as well as say a 6BTV, but it will work well with a decent set of radials.
73, and thanks, Dave (NK7Z) https://www.nk7z.net ARRL Volunteer Examiner ARRL Technical Specialist, RFI ARRL Asst. Director, NW Division, Technical Resources My favorite definition of an intellectual: 'Someone who has been educated beyond his/her intelligence'. Arthur C Clarke On 9/25/24 15:17, James Bennett via Elecraft 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 d...@nk7z.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
