Activating on the Road: Stealth Activating with the AX1 Antenna System
by Brian (K3ES)
As I prepared my radio gear to do Parks on the Air (POTA) activations across the states of the American West (Six Weeks and 7300 Miles: Activating on the Road), I knew that I would need to operate in a wide variety of different park environments. This need was primarily connected with differences in topography, vegetation, population, and regulatory environments.
A selection of wire antennas, a throw line kit, and some collapsible mast options would serve many of my needs well. However, I also expected that our travel schedule might require me to activate quickly or unobtrusively, from less-optimal locations. Since I do not have an HF rig or antenna system installed in my truck, any vehicle-based operations would need to use equipment from my portable POTA kit.
For these occasions, I intended to use either a wire antenna supported by a telescoping mast attached to back of the truck, or my diminutive Elecraft AX1 base-loaded vertical antenna system. During the trip, I found that I could use the AX1 to complete rapid, and extremely stealthy, activations.
I had ordered the AX1 antenna system from Elecraft early in 2024, and took delivery in March. I used it in a variety of configurations, gaining experience and confidence in its ability to make contacts (K3ES Travels: Ten Days of QRP with Compromised Antennas).
In early May, I also ordered an AM1-2 clamp-on antenna mount from ProAudio Engineering, and it had proved its versatility in deploying the AX1. All of this equipment and more found its way into a Maxpedition Fatty pouch, to become part of the stealth antenna kit packed for our trip across the country.
I Wonder if this Will Work…
Badlands National Park (US-0005) was one of the most spectacular parks that we visited on our cross-country adventure. I plan a future report with full coverage of the park and the activation, but the conditions in the park led me to make my first attempt at a truck-based activation. Shade was almost non-existent, the sky was cloudless, the air temperature was over 90°F, and the ground was too hot for POTA Dog Molly’s paws.
We pulled into a parking space at a roadside overlook, so that Becky could take some pictures, and I decided to try for a quick activation from the truck. After I set out a bowl of water in the back of the truck for Molly to drink, I pulled out my radio gear, and looked over my antenna options. I could have put up a mast and used a wire antenna, but I did not want to block access for other visitors, so my thoughts turned to the AX1 system.
The small size of the parking lot made it important to keep my operating footprint within the confines of my own parking space, both to avoid inconveniencing others, and to minimize the risk of damage to my antenna components. I decided to try attaching the AM1-2 clamp to the cylindrical base of my 2m/70cm mobile antenna, which is mounted on the front fender of the truck. The AM1-2 clamped on securely, and provided firm support for the the AX1 coil and whip. I also attached a counterpoise wire to the ground screw of the AM1-2, then tossed the wire under the truck to keep it on the ground, hidden, and out of the way.
That left two questions: could I get the antenna to tune, and would it radiate well enough to get contacts? I connected my feedline to the AX1, ran it in through the open driver’s window to the KX2, and quickly got answers to both questions: yes and yes. Continue reading K3ES: Stealth Activating with the AX1 Antenna System