View Single Post
  #16   Report Post  
Old March 21st 06, 04:07 AM posted to rec.radio.amateur.antenna
Sal M. Onella
 
Posts: n/a
Default vert vs dipole gut comparison


"Gary Schafer" wrote in message
...



You want both antennas if you can do it. Anyone who declares one or the
other the winner is simply wrong.

- 73 de Mike KB3EIA -


I did some tests a couple of years ago on 10 meters between vertical
and horizontal on an 1800 mile path. It seems that there is quite a
bit of rotation in polarity of the signal from minute to minute. I
tried right and left hand circular to confirm that it was rotation.

73
Gary K4FMX


Cross-polarization losses are in the neighborhood of 10-20 dB at VHF and
above. With my license, I cannot do HF, so others may chime in with those
numbers. Assuming ... there's that word ... that the random polarization
variations ("rotations") are around some central figure, during for a given
QSO, then one antenna will work better -- the one that happens to be optimum
for that path and for the antenna on the other end of the QSO.

There exists a phenomenon that I do not understand well, called Faraday
rotation, where an EM wave passing through a magnetic field will undergo a
polarization "alteration", so to speak. Thus, two verticals on the ends of
a long-distance QSO might not perform as well as if one were a vertical and
the other a horizontal -- due to the Earth's magnetic field.

John
KD6VKW