Topband: Low Dipoles

[Jim Brown]

On 12/14/2020 9:44 AM, donovanf at erols.com wrote:
> Bill's excellent: "You can never have too many antennas!"

For 160M contests, N6RO patches many components of his extensive antenna 
farm to the operating desk for use as RX antennas.

> is often quoted with my important corollary:
> 
> 
> "unless they interfere with each other"
> 
> which they all too often do...

Yes. When I added a 120 ft tower and sloping wire 160 verticals to it 
about ten years ago, N6BV and NI6T each told me in separate 
conversations that I should look for interactions with the tower, those 
sloping wires, and an existing Tee vertical about 200 ft away. I had 
already discovered the interaction between the Tee and coax feedlines to 
my high dipoles, and added ferrite chokes to suppress it.

I spent much of a summer studying those interactions in NEC, discovering 
that if I terminated unused feedlines for the 160 antennas, I could make 
the Tee a reflector for the sloping wires and the sloping wires plus the 
tower a reflector for the Tee, yielding me about 2 dB switchable to EU, 
JA, and to the south.

73, Jim K9YC