Re: Dummy Load Antenna


n5ib_2
 

About two years back I made an OzarkCon QSO Party dummy load out of NiChrome wire. Measured off enough to have a DC resistance of 50 ohms, which was about 50 inches for some fine gauge stuff I had here. It formed into a loop about 17" in diameter, using some polyethylene tubing to define the shape. Since the RF resistance would be somewhat higher I re-measured the formed loop with an antenna analyzer and trimmed for close to 50 ohms resistive part at 7 MHz. The loop, of course, has some inductance, and it took about 200 pF in parallel to tune out that reactance.

Some small PVC pipe and fittings to make a suitable stand and it was ready to QSO. Alas, I had so much fun chatting and visiting that I didn't put it on the air for more than a few minutes.

If you don't have any NiChrome you could achieve a similar effect by stringing a few resistors end-to-end in series, maybe with some wire between them to space them out enough for a loop a foot or so in diameter.

Jim, N5IB

PS... also check out in this group's Files section "Quick HF DF Loop.pdf " uploaded Feb 9 of 2017, as an idea for the oscillator hunt.

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