"Robert11" wrote in message
. ..
Hello,

Will be buying one of the new GRE hand held scanners soon.
Like all handhelds, it comes with the relatively short vertical whip
antenna coming out of the top; I guess they are also termed
rubber-duckies.

Not all that sharp with antenna theory:

My guess is that when held vertically, it is optimum for receiving
verticall Polarized signals, and my guess is, also, that all P.D.'s and
Fire Dept transmitters use vertically polarized signals.
Is all this correct so far ?

a. What happens if I lay the radio, with the antenna too of course,
hotizontally on its side ?
Will it still pick up "anything" ?

yes, 'rubber ducks' are not all that directive, though they will have a null
off the top and bottom that may be pretty good.. you would likely want to
avoid laying it on its side on a conductive surface as that may affect it
more than the polarization change.


b. Transmissions from airplanes: is there any meaningful polarization
from their antennas, or is it pretty random by the time it reaches the
ground, such that any any antenna orientation would be pretty much the
same ?

yeah, pretty much. though for high angle paths a vertical antenna may
produce a null that reduces the signal. but on the bright side they can't
be all that far away if they are almost overhead so the signals are stronger
to start with.


Thanks,
Bob