Repurposed Antenna Parts – Round 2

In a recent post, I wrote about a vertical antenna I put together with an old homebrew loading coil and a 12-foot telescopic whip. I intended to add some marks on the coil for each band, so I could eliminate the need for an antenna analyzer during band changes. This time, I actually remembered to bring a permanent marker and got it done.

I drove up to Evansburg State Park (K-1351/KFF-1351) this morning for a quick POTA activation. Before I got going, I used my antenna analyzer to determine the tap points for each band. I used a Sharpie® marker to mark the coil for 40M, 30M, 20M, and 17M. Since the coil has sufficient inductance to load the 12-foot whip on 60M, I also marked that band (the top-most mark on the coil). Before I started operating, I went back and checked each tap location to confirm repeatable results. Using a Sharpie marker is a decidedly low-tech approach, but it serves the purpose. 

My homebrew loading coil. If you look closely, you can see the marks I added. As shown, the coil is tapped for the 30M band.
My homebrew loading coil. If you look closely, you can see the marks I added. As shown, the coil is tapped for the 30M band.

To change bands now, I just move the tap to the appropriate mark. I still use an antenna tuner to deal with any minor variations I might encounter. Now I can change bands in the time it takes to move the coil tap and hit the “tune” button on the tuner.

Despite the so-so band conditions this morning, the 12-foot whip performed well. In less than an hour of operating, I made 18 contacts. Most of my contacts were on 40 and 30. There were two park-to-park contacts I’m aware of. 

The 12-foot base-loaded whip in use at K-1351
The 12-foot base-loaded whip in use at K-1351

My operations were interrupted for a chat with a curious park ranger. I gave him my standard Parks on the Air spiel. He had encountered POTA activators in another state park, so he had some familiarity with the activity. After a few minutes, he left to look into a reported issue on one of the hiking trails. 

So, I’m pretty satisfied with this antenna. It has a length advantage over my Gabil GRA-7350TC antenna. Comparing coil dimensions, I suspect it also has an efficiency advantage over the Gabil antenna. 

Regardless, I now have another useful option in my antenna arsenal.

73, Craig WB3GCK

2 thoughts on “Repurposed Antenna Parts – Round 2”

  1. YES! We need more antenna options. …and Sharpie marks are just fine.

    I keep trying to catch you when Ham Alert fires, but I apparently don’t have the right 40m/30m options to work you when the band conditions from Central Florida say “Nope, no farther than Georgia today.”
    Some day…

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