I am planning to build a 2-el 75mtr delta quad.
The plan so far is to use an old KLM monobander boom, 45'
long, fixed at the midpoint on the tower at the 95' level,
with a vertical truss. From each end will hang a pulley and
halyard.
On one halyard will hang the peak of the driven loop, and on
the other halyard the reflector. The ground slopes, so that
one lower corner of each loop will be 30' closer to the
ground than the other when the loops are staked out.
I have heard that its best to feed such an antenna from a
point a quarter wave from the top. I am not sure whether the
feed impedance will be close enough to 50 ohms that I can
just use a 1:1 balun and coax.
The wire will be 13ga stranded and jacketed copperweld.
Can anyone give me real-world measurements for the length of
the loops, or other advise. What gain should I expect,
compared to my present dipole horizontal at 95'? Will the
fact that the center of the loops is lower have a negative
impact for low angle radiation ?
Aloha,
Jonathan KH6X
Helen KH6T
kalepa@maui.net
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