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