As I mentioned in my recent AX1 vs AX2 video and blog post, I purchased an Elecraft AX2 antenna and bi-pod in late January (note: two days before Elecraft announced their February ’23 sale price! Doh!).

I received the AX2 package a few days later and I was certainly eager to take it to the field.

My first opportunity came on Tuesday, February 14, 2023, when a short activation window opened up in the afternoon.

Zebulon B. Vance Birthplace (K-6856)

One of the first things I noticed after taking the AX2 out of the package is just how solid and compact it is. The AX1 is short, but the AX2 is a few inches shorter because the base is more compact.

Unlike the AX1, the AX2 is a mono band antenna, thus the coil only needs to accommodate one band. When you receive a new AX2, it’s configured for 20 meters out of the box, but the user can modify the coil to work anything from 20 to 6 meters.

“Resonant-ish”

Even though I mentioned this in my AX1 v AX2 article and video, I’d like to reiterate that the AX2 is nearly-resonant on 20 meters. It is not reliably resonant.

I’ve still been receiving a lot of messages from readers stating that their AX2 and AX1 are resonant on 20 meters, so they don’t pack any sort of matching device in their field kit. They simply hook the AX2 up to their little QRP radio and hop on the air.

While it’s true that these antennas may provide an acceptable SWR most of the time, you really can’t rely on a solid, reliable match as you could with an end-fed half-wave.

I’ll repeat what I mention in a previous post:

Small verticals like the AX1 and AX2, that use coils to electrically “lengthen” the antenna, have a higher Q than, say, a large aperture quarter or half wave antenna. In practical terms, this means that the window of resonance is narrow and more fickle than, for example, an end-fed half-wave.

A lot of factors can affect the SWR on higher-Q antennas like the AX1/AX2 including:

• • • the type of terrain,
    • height off the ground,
    • length of counterpoise,
    • configuration of counterpoise,
    • and, most notably, the operator’s own body capacitance.

You may find that the AX2, for example, is natively resonant on 20 meters at one location, but isn’t at another location. This is quite normal. It’s also the reason why Elecraft states that both antennas are designed to be used with an ATU.

So there you go! If I hook up my AX1 or AX2 to a radio, I’ll always have some means of matching the impedance–either an external ATU, or a capacity hat. You can also tinker with the length of the telescoping whip and counterpoise to tweak the match.

The important part–especially if pairing these antennas with a radio that lacks both an internal ATU and SWR meter (say, the MTR-3B, G106, or TR-35)–is that you’ve some means to check the SWR before conducting a long activation session.

Setting up

For this activation, I was pairing my new AX2 with the Elecraft KX2 which sports a superb internal antenna tuner, so finding an acceptable match was not going to be an issue.

Set up couldn’t have been easier. Simply 1.) attach the 13′ counterpoise to the KX2, 2.) screw the telescoping whip on the AX2 base/coil, 3.) attach the right angle BNC adapter to the base, 4.) attach the bipod bracket and extend the bipod legs, 5.) then attach the AX2 to the KX2. That’s it!

All that’s left to do is find a clear frequency on the 20 meter band, then hit the ATU button on the KX2 to sort out any impedance mis-match.

Gear:

Note: All Amazon, CW Morse, and eBay links are affiliate links that support the QRPer.com at no cost to you.

• Elecraft KX2
• Elecraft ES60 Pack (Note that mine is a discontinued LowePro CS60 pack, the ES60 is identical and Elecraft branded)
• Elecraft AX2 with Bipod Adapter
• Key cable: Cable Matters 2-Pack Gold-Plated Retractable Aux Cable – 2.5 Feet
  
• Begali Traveler
• Spec-Ops Brand T.H.E. Pack EDC
• Elecraft KXBT2 Li-Ion Battery Pack
• Rite In The Rain Weatherproof Cover/Pouch
• Moleskine Cahier Journal
• GraphGear 0.9mm 1000 Automatic Drafting Pencil
• Zebra Mechanical Pencil, Del Guard, 0.7mm
• Camera: OSMO Action Camera with Joby tripod

On The Air

I started calling CQ POTA and within the first twelve minutes on the air, I worked the ten stations necessary to validate this activation.

I continued operating for eight more minutes and worked ten more stations for a total of 20 stations logged in 20 minutes.

Dang!

Let’s just say that the AX2 certainly impressed me on its maiden voyage.

The sad part, once again, is that I had to sign off with still a load of stations trying to call me. I had truly reached the maximum amount of time I could stay on the air and not be too late picking up my daughters after their class.

QSO Map

Here’s what this 5 watts into a 4 foot antenna activation looked like when plotted out on a QSO Map.

Activation Video

Here’s my real-time, real-life video of the entire activation.  As with all of my videos, I don’t edit out any parts of the on-air activation time. In addition, I have monetization turned off on YouTube, although that doesn’t stop them from inserting ads before and after my videos.

Note that Patreon supporters can watch and even download this video 100% ad-free through Vimeo on my Patreon page:

Click here to view on YouTube.

AX2 First Impressions

I don’t think I could have been more pleased with the AX2. I like how insanely compact this antenna is and how well it performed for me on 20 meters.

Speaking of which, these days, 20 meters tends to be the hottest band for both POTA and SOTA, at least here in western North Carolina during my daytime activations.

Depending on where you live, your mileage may vary.

Your mileage may vary using an AX2, AX1, or any tabletop travel antenna, in fact. I’m lucky that my normal 20, 30, and 40 meter footprint includes the majority of the amateur radio operators here in the eastern half of North America.

We posted recently about how Terry had mixed results using his AX1 antenna in Oregon. When your compromised antenna propagation footprint falls on sparsely-populated regions, it might take more time to rack up chaser/hunter contacts.

A lot of folks on that post noted (both seriously and jokingly) that some of my AX1 success has to do with my “celebrity” status. [First off, the use of the word “celebrity” in association with me is quite the exaggeration! Ha ha!]

That said, I get it. Some ops may enjoy working me because they’re a reader, YouTube subscriber, or maybe they want to hear what their station sounds like other the other end when I post an activation video. Frankly, it’s quite the honor for me that anyone would go out of their way to log me.

While I’m sure this factor may be in play to some degree, I’d argue it’s less than you might think.

When I operated the AX1 with my new Canadian callsign (VY2SW) in Québec last summer (photo above is one example), I found that I had the same amount of success despite not being as ideally located geographically. Very few people had VY2SW loaded in their Ham Alerts.

That said, if you live in a geographically-isolated region (in terms of propagation footprint) you will find that using a compromised antenna takes more patience and planning.

Here in the eastern half of North America? I feel like compromised antennas are quite effective pretty much anytime if your goal is to simply complete an activation.

Thank you

Thank you for joining me on this short activation!

I hope you enjoyed the field report and my activation video as much as I enjoyed creating them.

Of course, I’d also like to send a special thanks to those of you who have been supporting the site and channel through Patreon and the Coffee Fund. While certainly not a requirement as my content will always be free, I really appreciate the support.

As I mentioned before, the Patreon platform connected to Vimeo make it possible for me to share videos that are not only 100% ad-free, but also downloadable for offline viewing. The Vimeo account also serves as a third backup for my video files.

Thanks for spending part of your day with me! Here’s wishing you an amazing week ahead!

Cheers & 72,

Thomas (K4SWL)