Brenda Ann Dyer wrote:

"Henry Kolesnik" wrote in message
m...
How about frequency respoonse?

Of what? AMS radios have nearly identical freqeuncy response to FM radios.
Noise being the primary drawback... and even that isn't an issue in a high
signal area such as a large city. Back in the heyday of AMS, I used to
actually prefer to listen to KGW-AM over any of our local FM stations
because the signal was strong and clean and every bit as good sounding as
FMS, with the added advantage of not having to deal with multipath or picket
fencing. FM does have the advantage in distance over AMS for clean signal,
but only because of the reason William brought up.. limiting. You can
amplify an FM signal far beyond clipping without affecting the intelligence
contained therein. I don't believe early FM receivers had any designed-in
limiting, they just didn't have any gain.

It was very quickly realised that huge gain and limiting became necessary
fro reliable FM reception, since signal strengths vary so much, even in the same
room,
so they were designed to make a constant output signal to the discriminator
once the input signal was over a ver low threshold of signal level.
Increasing signal level 60 dB makes little difference to the reception.

AM signals would have to rely on very complex AVC if the stations's Fs were
placed between 88 and 108 MHz. FM is a much easier way to get a good result at
100 MHz.
But AM works fine at 1 MHz, and it potentially can sound equally good
to any FM signal. Most AM receivers are poor quality with low audio bandwidth
and high distortion.

Patrick Turner.