On 2/2/2012 8:22 PM, Wayne wrote:


"Bill Peters" wrote in message ...

I put up a 20 meter dipole array a while back and I don't seem to be
receiving the greatest signals. The height is fairly low, about 20',
and one part of the array is fairly close to an aluminum fence I have
surrounding the property. I'd say the southern leg of the array is
about 25' away from the fence. So I ask the question: what effect can
fences have on antennas and what are some possible solutions? I can
rule out moving the antenna because I lack the room to move it any
further away from the fence.

Thanks,
Bill
-
For clarification, is the "dipole array" more than one dipole?

You could configure a reference antenna by mounting a nominal 16 foot
vertical element on the fence, using the fence as a ground. (If you
don't have spare tubing, a wire taped to a bamboo pole would do) Then
you could get an idea of whether or not the dipole is working OK, or the
band being dead.

--Wayne
W5GIE

This works fairly well in my experience.

I have a Gap vertical with the feed 8 feet above ground and a 40 or so
foot dipole at about 27 feet. Both connect to an LDG AT100Pro. The Gap
needs virtually no matching and on 20 the dipole doesn't need a large
amount. RG213 at about 70 feet on each.

It is interesting to compare the two. It also makes one understand why
diversity receive antennas are really nice.

By and large the receive signal strength is close, which makes sense
given how the new wonder digital S meters work. Transmitting to ground
wave stations is as expected (again obviously roughly) when considering
horizontal v vertical.

tom
K0TAR