At VHF it isn't about man-made noise or ground loss.
VHF/UHF SSB is used for contacts way, way beyond the line of sight, and
horizontal polarization has significantly lower loss along paths
involving diffraction over obstacles. In other words, it works better.
(That would also be true for FM, but amateur FM has standardized on
vertical polarization because of the overriding need to use
omnidirectional antennas for mobiles and for fixed packet nodes.)
Horizontal is also mechanically easier for stacks of single yagis for
multiple bands.
Once you lock into one polarization as standard, the cross-polarization
loss means that everybody has to fall into line. But it's more than "cuz
that's the way it's always been done". There were - and still are - good
reasons for doing it that way.
73 from Ian G3SEK Editor, 'The VHF/UHF DX Book'
'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.com/g3sek
> I heard a discussion on 75m about 2m ssb antenna polarization. As I know,
>most ops on 2m ssb are horizontal. Why horizontal, and not vertical? ...
Because most of the local traffic runs with vertical polarization.
This will reduce the IMD problems, and allow you to run some nice low
noise pre-amplifiers on your directional antennas with less worry of
what the local repeaters may be spewing.
It may not be the reason why horizontal polarization was originally
used, but it's a good reason to continue.
73,
Jake Brodsky, AB3A mailto:fru...@erols.com
"Beware of the massive impossible!"
Ian, Thanks for giving a straight answer and not being a smart ass.
aggravates the crap out of me when someone asks a legitimate question
and seems all anyone gets is a stupid smart ass reply.
To be honest I was wondering the same question regarding
polarization. :) 73s, Billy
Horizontal has shown to reduce noise as you noted, provide Isolation
from the Vertical polarized FM operation on the band and studies and
experience has shown Horizontal has advantages on long part over the
horizon paths. In addition stacking H-pol antennas, Yagi or Loop, for
Base operation is easy.
Vertical was chosen for FM operation as they adopted the commercial
2-way standards, Vertical antennas are easier to install on vehicles
and Omni Gain antennas are easy to build for Base Station/Repeater
operation.
If you are going to do SSB on 2m you need an H-Pol antenna even a
single Loop will outperform a High Gain Vertical.
Ron
n5hyh