Antenna

I setup at US-1418 for an activation. I tried to setup the 40m EFHW in a nearly vertical configuration, but my throw wasn’t high enough, so I went for a vertical 25-foot Rybakov instead. I used my 4:1 balun.

I got my activation working 10M and 15M FT8.

The slim jim I put up for APRS was hanging right next to the feed line of the higher quarter-wave antenna I use for local analog traffic. The feed line was de-tuning the slim jim, so reception of APRS traffic was almost non-existent. I could swap the antennas and the higher one worked much better, and the lower slim jim was greatly degraded for other FM traffic. Usually the BTech is on the lower slim jim, and the Quansheng is scanning on the higher quarter-wave.

To correct the problem, I pulled the 2 antennas up on separate ropes and separated them by a couple feet. The quarter-wave is still mounted higher than the slim jim.

I went to the 985 breakfast and chatted lots of Vic and Jerry.

After breakfast, I hit the parks for some POTA. I started at Middle Creek where I tested my EFHW vs the Tactical Delta Loop.

Next, I setup at State Game Land 156 down the road with the telescoping antenna for a CB walkie talkie.

I had followed the these nice directions to build my 4:1 unun to use with a Rybakov and Tactical Delta Loop, but I made a mistake:

• the wires that come from the shield continue in opposite directions around the toroid
• on my bad build, they originally both went the same way side by side.
• the diagram is clear, if you look closely, but the picture is even clearer.

I tested the 4:1 with the tactical delta loop. It consists of:

• the 4:1 unun.
• 2 17-ft telescoping whips up diagonally 90 degrees from each other.
• 25-ft wire connecting the ends of the whips with alligator clips.
• 3d-printed plastic mount to hold it all at the bottom.
• screwdriver stuck through the mount into the ground to hold it up.
• alligator clips to connect the unun to each side of the loop.
• ground spike (screwdriver) wired to the ground side of the loop/unun.
• tuner is required to work 40M-6M. 80M and 160M didn’t want to tune.

I launched the newly-tuned slim-jim antenna. With it hanging from the fan, it looked tuned. Hanging right next to the siding outside the window, it looked long.

I launched it into the tree to hang right below the quarter-wave. Hanging in the tree, it looks well-tuned. I compared both antennas simultaneously with the 2 Quanshengs, and the lower slim jim measures 10-20dBm lower than the higher quarter-wave when receiving.

I reconditioned my HF antenna. The SWR was being wonky and variable on the 107ft EFRW: jumping to 3:1 with tuner. I cleaned up the wire ends and alligator clips with sandpaper, reconnected them, and repositioned the counterpoise. Now I’m seeing 1.5:1 SWR with the tuner.

The rope came undone at far end of my EFRW. I had to fish it back down with a wire hook stuck in a fishing pole.

The SWR was a bit high, and I found broken wires in 9:1 balun, so I stripped the wires and reassembled it.

With the antenna working again, I contacted New Caledonia on 10M FT8 with 8W.

The quarter-wave ground plane antenna in the tree disconnected in the wind, so I brought it back down and rebuilt it stronger with radials passing through the holes and woven together. I used randomly shorter radials, but 8 of them this time. I watched the SWR drop with the nanoVNA as I added radials. I resoldered the driven element into the socket and trimmed it to tune it again.

I took along the old slim jim antenna I bought at my first ham fest. I understand now better how to tune it: I need to make it a little longer, not just slide the feed point up and down the batch.

The antenna was a little short by measurement with the NanoVNA. I hung it from a fan in the middle of the room to measure it without interference. I lengthened it at the far bend by soldering some extra house wire in the bend.

Now it looks perfect for 2m and 70cm.

The new 107-ft (32.6m) EFRW in the backyard is doing OK, and I’m getting pretty lucky with low power on 10M FT8.

• Japan (10500 km): 5W, 2025-02-10 2245 UTC
• Norfolk Island (14000 km): 2W, 2025-02-11 2238 UTC