Steady on Mal ! this is getting technical
!"
Your right , FM has a cut off point ,
where demodulation fails and also a
capture effect , where the stronger of 2 signals
will acquire and hold the demodulator
..always fun on 2 mtrs when a
mobile suddenly takes the channel
Am has no cut off point , but gradual
degradation until the recovered audio is no
longer usable ......eg, mcw would readable
much lower than AM speech
I think much over 250/300 MHz its
actually not possible to produce AM , could
be wrong , but there is a limit ,
may be by high level modulation falls over
, dont see why could not be via
transverting .......
G..
Sent: Tuesday, June 26, 2012 8:36 AM
Subject: LF: A/G FREQS
As stated Air/Ground vhf/uhf is AM and
simplex working. I have also noticed a well modulated AM
transmitter is more potent than a FM transmitter when working at max range. On
AM the RX bandwidth can be opened up to receive several stations
simultaneously then select the one of interest by closing down the
selectivity, the same applies on CW. On FM if you tried this
the transmission would fall into a black hole, in other words the FM
rx has to be tailored to the exact bandwidth of the transmission (same
deviation value)
g3kev
