In article
,
Art Harris wrote:

BCBlazysusan wrote:
Something I read on one of those links in reference to antenna height,
it says the optimal height in 25ft. That was the first height I put it
at. But I noticed a real difference at 40 ft...it was quieter. I then
upped it to 45 ft. with no difference and finally to the 55ft. All I
know is something made the noise floor go even lower. It may have been
the height and the ground or a combination of the two. Kind of hard
for me to believe that an antenna at 25 ft. would receive as well as
one at 55 ft. but who knows.


It really depends on the frequency you're trying to receive. In
general, an antenna height of 1/2 wavelength above ground is something
to aim for. At 14 MHz that's about 33 feet; at 7 MHz it's about 66
feet.

At vhf/uhf, height is everything due to the line-of-sight nature of
those signals. At hf, not so much so (although it never hurts).

Because the OP is using a single wire antenna the signal to local noise
will improve with the single wire height at any frequency since the
distant signal volts per meter differential increases between the wire
and counter poise at the ground level with height.

The counter poise is grounded so local common mode noise has a place to
go other than the receiver input and with increasing height the single
wire is farther from local noise fields, which curve back to the earth.

--
Telamon
Ventura, California