"Dave99" wrote in message
...
Thanks guys... Up until now I hadn't used a Balun. Not to open the
balun debate, but I haven't used one on other versions I've done and
everything was fine. The testing I did was out in the middle of
nowhere, so that limits the chance of their being an outside signal
influence. Jerry, if you were asking if the whole antenna is isolated
from the mast... it is. There's no electrical contact between the
antenna and any part of the mast. The antenna is supported by a thin
horizontal 12" mast to the side of the boom. The antenna is isolated
from that part as well. So that holds the antenna about 12" away from
the parallel vertical mast. I actually put one up at a friends house
today. Interestingly enough it was doing the same thing on the ground
as the other one. But when we got it up on the mast about 10' off the
roof, the SWR was excellent across the whole designed bandwidth. So I
don't know, maybe something as simple as proximity to the ground? Like
I said, it's not a big issue for just receiving, but it just kind of
bugs me. Then of course, as you mentioned, there's the analyzer
itself. But I'd think if it was an error in that, it would just stay
the same... Not change by moving the coax.

Dave

Hi Dave

I did misunderstand about your mount. But, if the vertical antenna is
supported by a 12 inch horizontal mast, I wouldnt expect the support to
effect the radiation. But, when coax is used to feed a balanced antenna,
some sort of device is recommended to minimize conducting currents along the
Outside of the coax. One method of gfeeding a Log Periodic is to run the
coax inside one of the two tubes that form the parallel line connecting the
dipoles.

Jerry