Antenna

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.

a header at h3

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

I was using the 71-foot (21.64m) EFRW antenna at home, and I noticed SWR was surprisingly low as measured by the X6100 with the tuner disabled. I suspected loss on the feed line, but I also found this video of another person not using a tuner with the same antenna.

I disconnected my feed line at different places to find SWR jumps way high, so the measurement is working:

• inside window
• outside window
• at the antenna

Does a very long wire have low SWR for everything? Is the 9:1 giving low SWR? The antenna’s working fine, and FT8 shows far-flung signals like always. Disconnecting antenna wire raised SWR above 1.5:1, but not much. Even with wires disconnected from the balun, it’s receiving a very few FT8 signals on 10m, and I can still transmit, but it’s folding back power with SWR just below 2. The tuner is definitely needed for 6m.

The 1/4-wave ground plane antenna in the tree dropped its feedline, so I brought it down to reattach it and resolder the radials.

I also walked down the yagi on the pole to straighten some elements, since it was a nice day. The yagi was spinning around in the wind, so I also changed the way it’s mounted to clamp it more securely.

I also added some reigns to the mast, so I can (try to) spin it from inside the window. It works well some times but not others. The pole can freeze to the ground.

I watched a video about NVIS NVIS achieves 75-90 degree take-off, very vertical, and about a 400-mile range. It can get you over obstacles. It’s most effective on 40m and 80m.

To build it, mount a dipole 1/8 wavelength above ground, horizontal. Add a reflector almost on the ground, 5% longer, to keep the ground from absorbing the signal.