Re: What kind of antenna?

Detrick Merz

I use a doublet, made from speaker wire and some short sections of 1/2" PVC pipe, cut for 40m. Mason line is used to hold up the center as well as tie out the ends. The mason line is one one of these reels from a home improvement store. I measured out two lengths of line, cut them off, and wrapped them on the top of the reel. Those get spooled off first, and laid out for tying out the ends. The feedpoint is held by the line on the rest of the reel (the reel has ridiculously more line than I've ever needed). Typically, I'll use trees for support. A trailer-hitch mounted telescoping fiberglass mast (spiderbeams, jackite, or similar) is on my wishlist, primarily for winter operating. I'd prefer to be at a park bench or on the side of a trail rather that stuck in a vehicle, but I also have temperature/comfort limits. :)

To build the antenna, the speaker wire was measured out for 40m, marked, more measured out for the feedline section, and split apart completely. I used somewhere around 75' of speaker wire in total, although I likely have far more feedline than I'll ever use (some day I'll probably shorten it). The system uses (3) 6" pieces of PVC pipe. Each piece has holes drilled 3.5" apart, centered (the top piece has some extra holes for strain relief). One piece is at the feedpoint, another is placed at the ground somewhat directly below the feedpoint (this one also has slots cut to "lock" the feedline in place), and a third at my operating position. With just a small amount of tension at each point, the feedline stays nicely parallel. Everything except the mason line weighs 1 lb 13 oz. (antenna, feedline, pvc, bungee, aluminum gutter spike for ground anchor).

Prior to using this antenna, I used a similar one which left the speaker wire together for the feedline. Pictures here:

The new version of the antenna, described above, seems to greatly outperform the first version. I operate using a KX3, and both tune up nicely from 80 up, but I suspect the older version was getting a good SWR largely due to higher losses. With the first version, I was often getting 339 reports struggled to make a couple of voice contacts. With the new version, signal reports were consistently improved, and voice contacts (albeit as a hunter) were generally possible any time I could hear another op. I ran the first antenna primarily at 5W, and the second one almost exclusively at 15W, but still not huge power either way.

73, 44,


On Mon, Jan 15, 2018 at 9:05 AM, <kffcoordinator@...> wrote:
What kind of antenna do you all use if you are an activator? I have a LNR Trail Friendly End Fed and just got a Packtenna for Christmas. I use a 12m Spiderbeam pole with a homemade drive on base.

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