I wanted to share my recent activation at Morron del Mediodia (EA7/GR-006) my experience using my new AX-1 antenna in the EA weeked event.
The hike to the summit was enjoyable, with about 800 meters of positive elevation gain, and great views from the top, seeing Mulhacen the hightes mountain of Peninsula Iberica. Once on the summit, I set up the AX-1 using a small tripod from QRProject and was pleasantly surprised by its performance. The antenna was easy to deploy, lightweight, and worked well across multiple bands using the rig tuner. I made several contacts, with EA and Europe, using my XieguX6100 runnig 5w with not external batteries, which really highlighted the efficiency of the AX-1. I was particularly impressed with the stability and resonance, even in windy conditions on the peak.
Overall, it was a very positive experience, and I would definitely recommend the AX-1 for portable SOTA activations. It proved to be a reliable and convenient antenna, especially for hikers who need somthing quick and lightweight.
Thank for this interesting report Manu! Did you test the AX-1 and CP (I guess) against an EFHW or a random wire on the rocks? Would be an interesting comparison.
Hi Peter!, if you look at the picture of the AX1 mounted on the small tripod, you’ll see the counterpoise attached to the tripod. This antenna is fantastic for a quick activation or a long hike where you don’t want to carry much weight. Of course, I imagine that a long wire or an end-fed antenna would perform better than the AX1, but I’m impressed at how well it works despite being so tiny.
Thank you for your quick reply Manu! For a lightweight antenna, I like to throw a few meters of wire on the ground and tune with a L match. On the assumption that adding a 1m radiator with an inductor will help little with radiation, and will mostly ease tuning. But I have never tested my assumption, not having an AX1 type antenna.
That homemade AX1 looks good. Was it expensive to make?
Here is my setup. Works great with 5w on the KX2 or 100w on the 891 (it can handle up to 300w - possibly 500w, I forget). I use it with either a Hama full-size tripod, or a little Manfrotto portable tripod which is great as you can use it as a monopod or a tripod with adjustable leg height and articulation.
It isn’t cheap, granted, but it has got me DX on 10w across the USA, The Azores, Russia and more on 20m SSB and CW. Super easy to set up and lightweight (and it can do 2 and 70!).
Commercial antennas are usually quite complex to set up. They have various coils and radials. The price/performance ratio and even the pack size and weight aren’t always convincing. … and whether it can always be used without a tuner - I have my doubts.
Now I’m the happy owner of a KX2 with a tuner and have a 5.8 m random wire with a 1:9 Unun as an alternative.
The wire is attached to the top of the Decathlon mast and pushed up. After the Unun comes some coax with a current balun. The coax shield serves as a counterweight up to the balun. The Decathlon mast is placed in a fishing rod holder. The cost for everything was about 35 euros.
At the SOTA-BW meeting, Roman @DL3TU and I compared our antennas. Roman had a telescopic antenna with radials and various coils. We couldn’t detect any difference when quickly swapping the antenna connectors. A QSO with Ignacio @EA2BD didn’t reveal any differences either.
If you have a tuner that can handle a random wire/1:9 Unun, then you can be happy with a single piece of wire. By the way… in the time it takes to set up such an antenna with a coil and radials, I’ve already made my first four QSOs.
The advantage of these antennas is clearly their flat radiation pattern. On May 22nd, when D4DX/P was QRV on 10m on D4/IB-023 , I tried calling him from EI/IW-035 with the endfed for a long time without success. I then switched to the 5.80m wire vertically on the mast and had him on the first call: S2S with D4 - nice!
Nice read, Armin, but you should have mentioned that you had a head start
Nevertheless, I completely agree that beating the setup time of your vertical random wire antenna is hard. This efficient approach is certainly the result of the many activations you do.
Nice setup, Roman! I really like your 3D-printed support for the BNC plug, it looks sturdy and practical, and it’s a clever idea to keep the whip antenna stable, congrats! and I hope S2S soon.
You have convinced me to give it a try. I’ll build Roman’s whip for my QCX on 20m and test against my wire on the ground. And of course report back. In any case, neat ideas and food for thought!
Thanks Manu, also for sharing your experience with the AX-1. Hope to have a QSO soon!
I’m looking forward to reading about your experience, Peter!
I made a really stupid mistake during my last activation when I didn’t extend the whip to its full length. But even then I got three QSOs on 20m and 13 QSOs on 30m in the log - thanks to my chasers having great ears!
I have also successfully used the Elecraft AX-1 on many activations here in Arizona, along with the AXE-1 40/30m extender coil and 2 counterpoise wires. The results were beyond my expectations. While signal reports received are generally less than what they are with my resonant end fed antenna, I routinely make contacts with stations all over the United States and occasionally in Europe. The QSO map below is one of my more memorable activations using the AX-1.
encouraging to read. I’ve used the same setup — the AX-1 with the AXE-1 coil and two counterpoise wires, and I’m also impressed by how well it performs for such a small antenna.
On my second activation with it, I even managed to work two stations in the USA , which was quite a surprise for a tiny whip running QRP!
It’s great to see what’s possible with good conditions and a bit of patience.
73 and hope to catch you S2S sometime,
Manu
So I built my cheapo AX-1 clone. A small box that fits well with the QCX 20. Whip 1.4m from Ali, single CP 4m. Toroid-wound inductors for resonance at 14.060 and 10.116. SWR varies as Roman has noted quite a bit with the surroundings; typical 1.8 on 20m and 1.2 on 30m. Sufficiently reliable; no need to carry a SWR meter, as the QCX is forgiving.
My purpose in doing this was to prove to myself that my standard trapped EFHW on the ground is just as good. Well, that proof did not work out!
I am not claiming that I did a scientific analysis, just some impressionistic data from RBN, enough to convince myself.
On 20m, the whip and the EFHW on the ground are similar. About 12dB down on the EFHW 6m up in the air. The whip against the EFHW on the ground slightly better by perhaps 3dB, at most. Twice the number of spots with higher SNR. Probably within the error margin of such impressions, but in any case not worse than the EFHW.
On 30m, big surprise. No RBN reports at all for the EFHW, but plenty for the whip, with decent SNR.
For quick activations, which is the normal way for me (I am typically hiking with my XYL who is not so keen on radio), it is the whip from now on. The EFHW will become the backup; up in the air it beats the whip hands down, which is why also Elecraft is suggesting to carry 2x7.5m in case conditions are poor.
I know one’s antenna ‘sweet spot’ [lowest SWR at your favourite frequency] can move up / down frequency alarmingly at different locations and antenna set-up [e.g antenna height, wire slope angles, large objects in the near field, soil type]. Having to carry a SWR meter would seem to diminish the main benefits of the QCX, i.e. its small size and weight.
I’m just glad I have an HF rig whose internal ATU works magic and even for my monoband AX-1 clones.
, which was quite a surprise for a tiny whip running QRP!
