"Ed" wrote in message
. 92.175...


For FM Broadcasting this is VERY IMPORTANT. Originally, FM
broadcasters used horizontal polarization (usually versions of
"halos"
) for their broadcast antennas. This was fine for fixed or home
listeners, who used horizontal TV/FM antennas or folder wire
dipoles
(included with many stereo receivers) - BUT cars and mobile FM
receivers tended to be vertically polarized.

I believe the trend in modern cars is getting away form vertical
FM
receiving antennas and going to in-glass horizontal wires for the
antennas.


Ed

I would agree that some manufacturers - Ford and BMW to name but two -
have in the last decade or two used heated rear window antennas, but
if you look closely you will find that they have vertical components
as well - the side connector strips and often a 'joining' strip down
the centre as well. If they did not, by definition, the horzontal
elements would make the aerial quite directional - as the
manufacturers found out the first time round in the '70's.

In Europe and certainly the UK (a) many transmissions are not circular
but of mixed polarisation (i.e. crossed diagonal) to give a vertical
component for car and portable use and a horizontal component for the
many still horizontal roof aerials fitted over here from the days when
all FM was horizontal, and (b) many cars over here have either a
conventional angled whip on the front of the roof (as with Citroen and
Peugeot) or the ubiquitous 'bee-sting' amplified whip on the rear of
the roof.

One does notice how many American import cars over here still have
wing mounted vertical aerials - perhaps that is why there is so much
difference between them and us?


--
Woody

harrogate2 at ntlworld dot com