Re: Fire In The Wire

Gwen Patton
 

I made a simple linked dipole for 40/30/20 that deploys easily and mostly doesn't need any additional tuning. I have it set to the CW portion of the bands, so if I'm up on the top end of the phone portion of 40 or 20 it might stand to be tuned a bit, but it'll get along without it. You just tune it when you build it for the parts of the bands you want to operate on, and then it's just set it up and operate.

I made it out of 24 gauge silicone-insulated stranded hookup wire. A bit of scrap plastic became the feedpoint, and I used 2" wood dowels with holes drilled through them at the ends between the segments on the legs. Some simple spade-type connectors make it easy to link up the segments, and they're easy enough to disconnect when you want to change bands, but when connected they have good, solid connections that don't affect tuning.

There's tons of sources for link dipole calculations, and plenty of sites that detail a link dipole's construction. Mine is wound up on a pair of simple plastic winders to keep it from getting snarled. The coax is the RG-174 thin stuff, with a pre-soldered BNC connector. I got a few of 'em from SOTABeams the last time I ordered from them, but you can get premade coax cables of just about any type. Or you can make your own cable if you've got the bits and pieces. I've got the crimp-on connectors and tools for RG-8X, but not the thin stuff, so I bought the cable pre-made. I didn't use a connector at the feedpoint, because I first built it with a 1:1 balun at the feed, but I couldn't get it to tune so I took out the balun and just soldered the wire and the braid to the legs and left it at that. Tuned perfectly after that. Here's the site I used to design mine. The only caveat I have is that I didn't use the 3d printed bits because when I built it I didn't have a 3d printer. If I were building it today, I'd go that route, since I have one now.  http://www.oe8hsr.at/blog/?page_id=345

I use a cheap 7.2m telescoping fiberglass mast to erect the antenna. I either set it up freestanding with guy lines, or I use a drive-on mast mount and park my van on it. The endpoints either stake into the ground, or I anchor them with photographers' sandbags I carry for such purposes.

If I don't use the link dipole, I may use an end-fed with a simple tuner built in for the same bands from SOTABeams, or my Wolf River Coils vertical. The vertical works REALLY well, but it's best to have an antenna analyzer with you to tune it more easily. You can work around it if you don't have an analyzer, but it's a pain. 

73,
Gwen, NG3P


On Sat, Mar 14, 2020 at 4:16 PM Johnny Matlock <jomatlock@...> wrote:
Ge Jim
Very nice article.
Thanks for sharing.
72
Johnny AC0BQ 

On Sat, Mar 14, 2020 at 3:10 PM n5ib_2 <n5ib@...> wrote:
I'll share a little article I wrote for our club newsletter a few years ago
PDF attached .... if I did it right  :^))

Jim, N5IB



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