Our ARES group plans on installing an Inverted V antenna on the
second story flat roof edge of a local building. The antenna mast is 13
feet tall above the roof edge. The Inverted V will run parallel the edge
of the roof and be approximately 35 - 40 feet per leg. Our primary
operations will be 80/75/40M with a desired ability on 60M. The
building custodian/owner will not tolerate open wire feedline with its
associated standoffs due to aesthetic considerations, so we must feed
this antenna with coax fastened to the mast. At the base of the mast,
on the roof, we will be using an SGC-237 antenna coupler.

The above setup is a given, with no room for compromise.

My questions for this group are as follows:

Would we be better feeding the above antenna feedpoint with twin coax
runs, using the center conductors as a 'balanced' feedline, or would we
be better of using a single coax to the feedline? In either case, the
coax runs will not exceed 20 feet and we must accept the losses in them.
Email response from SGC seems to indicate we would be better off with a
single feedline, but I am dubious about the SGC Tech Rep's response
since he/she does not seem concerned about feedline radiation.

Also, what recomendations do you guys have for use of a balun? I
believe, at the least, we would need a 1:1 balun at the Input of the SGC
coupler so as to keep RF from getting back down the shield and into the
building. SGC response seems to indiate they don't think a balun is
necessary anywhere, which is another reason I am not thrilled with
their response.

Comments?


Ed K7AAT