"Doug Kanter" wrote in message
...
1) No experience with other peoples' car radios. I understand that MY car
radio may have problems dealing with the strength of this particular
signal.
Do you perhaps have a $5 radio you can try this station on? Or could you
pick one up?

2) The distortion occurs ALL the time, and NONE of my travels are in the
vicinity of high-rise buildings. However, I'm always within 3-5 miles of
the
transmitter, which is on the highest point in this city.
It's possible being that close that you are getting skywave and groundwave
cross interference, or reflections... though on FM that would be more a
picket fencing effect I would think... Hmm is there another nearby FM
station? (nearby both in frequency and location) You could be getting
splatter off of them affecting your signal.
3) I understand all the other possible causes you mention, including the
times when you stop your car and seem to be in a "node" of lousy reception
which is gone when the car moves.
The only other non-scientific clue I have comes from an acquaintance who's
been involved with the radio biz in this city for about 20 years. His
highly
rigorous analysis: "They compress the CRAP out of their signal so they can
tell advertisers they'll be heard 90 miles away".
What he means is this: An FM signal is 'frequency' modulated, meaning the
signal is splattered over a (compared to other modulation types) large
section of the band. (this is called the envelope... specifically for FM
they refer to it as the 'Deviation' of the signal). When you run a signal
through an amplifier, you have to amplifiy the whole thing; When you amplify
an FM signal by 1000 watts, you are getting less 'effective' amplification
than several other modes, because the signal is wider. If you can compress
the signal by, say, clipping the lows out before it's modulated, or even
just lowering the deviation a bit, you get a higher effective signal level.
This is the magic of Ham radio's CW (morse code) mode, in that it compresses
the signal down to one tiny little spike. If the signal is crunched enough,
audio quality suffers. If the section they transmit is a section the audio
on your radio doesn't do a good job with, it sufferes even more. We have a
local station that band-pass filters everything... they sound like they are
playing at the bottom of a coffee can.
Another possibility is simply the 'front end' of the radio is being over
driven so much it's distorting, or having trouble locking on the signal.. or
perhaps the deviation is too high. Can you hear the signal 'off frequency'?
(tune up or down a bit)
Suggestion: Pick up the cheapest radio you can find at Walmart or Radio
shack. Try and see what happens. I picked up a micro radio as a birthday
present for a friend's kid for $5 on sale at rat shack... think it was
clearance though.

One other thing: look for a 'local' or 'lcl' button on the radio... I just
remembered my car radios have always had them... it's to help with the
clarity of a 'local' radio station I guess. Couldn't hurt to try it.