Many thanks to Conrad (N2YCH) who shares the following field report:
Top Band POTA Activation Field Report
By: Conrad Trautmann (N2YCH)
November 15, 2023
In February 2023, Brian, K3ES, wrote here on QRPer.com about designing and building his own QRP portable random wire antenna he called the VK160 to work on 160 meters to make parks on the air contacts. This was in order to achieve his goal of getting the James F. LaPorta N1CC award where activating on 10 bands at 10 parks is needed. It’s not as easy as it sounds. As an avid parks on the air activator myself wanting to try activating on 160 meters, I built my own antenna based on Brian’s design and used it to get my first contacts ever at a park on the “Top Band.”
Brian used a 9:1 unun that he built himself in his design. Rather than build my own from scratch, I took a short cut and bought a QRPGuys 40m-10m UnUnTenna to use as the starting point for my VK160. Even though it says 40m-10m, it works on 160 meters, as you’ll see.
With shipping, it cost $36.00. It comes with all of the parts you need to assemble the antenna except for the wire. The main thing I liked about the QRPguys design was that the circuit board also doubles as a wire winder, so it’s all self-contained.
I sourced the wire from Davis RF and ordered 200’ of “POLY STEALTH – 26 AWG, 19 0.22000 44.00 STRAND COPPER CLAD STEEL, BLACK PE JACKET.” It cost $50 including shipping. The polyethylene insulation prevents the wire from knotting up. I measured out 144’ for the radiator based on Brian’s design and used the remaining wire as the counterpoise.
I did a back yard test once it was all assembled and it worked great. For $86, I had created my own VK160. I encourage you to read Brian’s detailed design/build report here.
The POTA Activation – November 14, 2023
Now that I had completed building and testing the antenna, the next challenge was how to actually put it to use at a park. 160 meters doesn’t really come to life until dusk or after dark. In Connecticut, most state parks close at dusk. The park rangers clear the parks to close them at the best time to activate the band. However, there is one park nearby my QTH, the Stuart B. McKinney National Wildlife Refuge, K-0228, that has an annex called the Great Meadows Unit in Stratford with a nice parking lot that is not gated and has no posted hours. I arrived and set up at sunset, around 4:30 pm ET and operated from 5 pm until 6 pm. It gets dark here early in the Northeast US in November.
Another challenge is how to manage and string up 144’ of wire. Brian suggested an inverted V over a tree branch in his write up. There were no trees nearby, so instead I used a Spiderbeam fiberglass pole secured to my Jeep to get the feed point up in the air about 25 feet. I used RG58 cable from the feed point to the radio.
Finally, I used one of my $3.00 Home Depot electric fence posts to secure the far end to keep it tight and up in the air and set up the antenna as a sloper. I laid out the counterpoise on the ground under the sloping wire.
By the time I had all of this set up, it was getting dark. I connected my Elecraft KX3 to the other end of the RG58 cable and to my surprise and delight, I was already receiving stations.
My KX3 has a built-in ATU and one tap of that ATU button and it tuned to 1.0:1. I started the activation right at 5 pm local time and in about 15 minutes, I had six QSO’s on 160 meters.
The PSK Reporter map showed me being received by stations on the dark side of the gray line in the Northeast. It was pretty much what I expected for QRP power on the low frequency. Then, the next ten minutes things were quiet. It appeared I had gotten everyone who could hear me.
Since this is a random wire antenna, it should work on all bands so I decided to test it on 80 meters. Again, the KX3 tuned right up and I got six more QSO’s. I was surprised to see Del, N2NWK from Washington, DC pop up on JT Alert. I have a an alert set for stations calling CQ POTA. Del was also at a park. I called and he answered and we ended up with a park to park. Anyone who knows Del knows that when you hunt him, he’s usually activating at a two-fer, at least. When I checked my hunter log afterwards, I saw four parks listed from him (a four-fer?).
At this point in the activation, I had gotten the ten QSO’s that I needed to call the park activated. I thought, let me try the VK160 on 60 meters. I re-tuned the KX3 and got five more fast QSO’s. The antenna worked great.
Before I packed up, I decided that I really wanted at least ten contacts on 160 meters, which was my original goal. I went back to 160 meters, now close to an hour later than when I began the activation, and easily added five more new QSO’s to the log. Maybe propagation had changed the later/darker it got or some new hams were on the band who weren’t on earlier, but I was satisfied to have gotten more than 10 on the top band.
Here’s how I did. Green pins are QSO’s on 160 meters, blue pins are 80 meters and the pink ones are 60 meters (click image to enlarge).
- Mindshift 18L Camera Bag Backpack for radio, cables, battery and computer
- Elecraft KX3 with CIV and audio cables
- Bioenno 1x 12V, 9Ah LFP Battery (PVC, BLF-1209A)
- Samsung Galaxy Book Flex2 Alpha 2 in 1 Laptop with Outdoor mode
- Sabrent USB external sound card adapter
- VK160 Random Wire Antenna
- Buddipole 15’ RF coax and choke balun
- Spiderbeam 10m Mini Fiberglass Pole
- Home Depot 3’ electric fence post
The “Top Band” activation was a success! The VK160 worked flawlessly, thank you Brian, K3ES for posting your design and providing the inspiration to activate on 160 meters.
My POTA “My Stats” page now shows 11 digital QSOs on 160 meters that I didn’t have before. I love conquering new challenges and given the challenge of going mobile with an antenna that will actually work and tune up on that low of a frequency at a park that won’t make you leave at sunset, well… that was quite an accomplishment!
Thank you to the 22 hunters (11 on 160 meters) who helped make it a success, including my friend Del, N2NWK in Washington, DC.