On Dec 12, 11:27 pm, "AI4QJ" wrote:


Thanks for your comments. Do you believe there is any technical basis for
claims that vertical antennas are noisier than horizontal antennas due to
more man made noise being created with vertical polarization? This makes
inverted V an ideal compromise?

Yes and no.. Just depends on the polarity of the noise.
On 40m, I've had the luxury of being able to run both full
size dipoles, and a full size elevated ground plane
at the same time. Myself, I don't consider a vertical any
noisier than a horizontal antenna as long as the noise
source does not match the polarity of the antenna in use.
I've seen cases where local power line noise was just
as bad horizontal as it was vertical.
I'm in a big city, and I've never found noise to be any
great problem on a vertical. Overall, it was no worse
than the dipole.
And even if the background noise is a bit higher on the
vertical for some reason, the advantages of it's pattern
override and swamp any problems the noise might cause.
IE: say I'm on 40m at night working VK land.
The dipole shows a resting noise level of S 5 as an
example.
Say the vertical shows noise at S7.
Being the usual advantage of the vertical to VK land
was 4 S units vs the dipole, the 2 unit increase in
noise becomes a non issue. The higher level
of the desired signal swamps the extra noise.
Now , if you had a strong noise source that was vertical
with little horizontal componant, it could be more
of a problem if it happens to override even the large
increase in desired signal, but that not a fault of the
antennas. They are just acting as they should.
IE: the elevated GP did much better at the low
elevations vs the dipole. So it's going to be natural
that it also receives local noise farther away than
the dipole. But I don't consider this as a "fault".
It's just acting as it should. RF is RF is RF.
I can tell you, if I'm working VK or EU and have
the choice of the dipole, or the GP, I'd take the GP
any day of the week, extra noise or not.
It will be rare for the noise pickup to exceed the
increase of the desired signal.
So basically, I consider the vertical vs dipole noise
issue, a non issue.. :/
MK