I have a theory about this.
Compare a vertical to a dipole. One reason for additional noise is that
a vertical is omnidirectional, and noise comes from all directions. The
signal is coming from one direction, and if it is the right direction,
then the 2.2 dB gain from directivity of a dipole improves the s/n ratio
by that much. But subjectively the difference seems greater than this.
It's also true that the vertical is better for signals off the side of
the dipole.
As Brian said, most verticals appear to be far noisier in urban
environments where there is a lot of manmade noise. I believe that this
is /not/ because manmade noise tends to be vertically polarized, as is
often said.
I believe that it is because most verticals are not adequately decoupled
from the feedline. Therefore, manmade noise is picked up on the outside
of the feedline and flows directly into the antenna.
This is exactly the same problem that happens with a dipole without a balun.
Therefore the solution to the problem may be a good choke 'balun' at the
vertical's feedpoint.
On 6/26/14 1:38 PM, Brian Hunt wrote:
The other thing I have encountered with verticals vs horizontal antennas
in an urban environment is that verticals are inherently noisier.
--
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco/
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[email protected]
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [email protected]
