Topband: Delta RX antenna

[N2TK]

I have build one - 72' total wire. It is pointed northeast. I also have a
set of ewes that I use as a reference. My ewes are more like a loop than an
ewe. I added an insulated wire on the ground that ties the feedpoint and
termination points together. Also I lifted the connections to the ground
rods. Also I feed both ends with 12v through the coax so I get 6 directions
with 3 ewes.
For the delta loop I use an autotransformer to feed it. It is difficult to
tell a difference between the delta loop and the ewe towards the northeast.
If anything, the ewes hear a little better but the delta loop may be a
little bit quieter. I tried an off the shelf transformer that has isolated
windings, but the signal dropped considerably over the autotransformer. Went
back to the autotransformer.

Set up a very short vertical 50' behind the delta loop. Hooked up my MFJ 259
as a signal source. Set up a receiver at the loop. Put a non-inductive pot
in place of the terminating resistor. Adjusted the pot for lowest signal on
3.5, 3.8 and 1.83 MHZ. Found a fairly sharp dip for each freq. Not sure what
it all means yet. Ordered some Vactrols so I can add one to the loop and see
if it helps.
3.5MHZ - 840 ohms
3.8 - 1040
1.83 - 765

Tony, N2TK



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