Topband: Shunt feed vs sloper

R. Dean Straw
Tue, 11 Sep 2001 07:54:45 -0700


Concerning quarter-wave slopers:


> I believe the current thinking is that they act like an inverted Ground
> so they MUST have some sort of top-loading (usually one or more Yagi's)
> them to work properly.

Modeling shows that this is true -- the Yagi acts like a top "counterpoise"
for the sloping wire. Indeed, removing the tower from the model essentially
doesn't change the feed-point impedance nor the radiation pattern for the

Anyone who wants a copy of the EZNEC modeling files can ask me directly by

73, Dean, N6BV