Transmitter/receiver crystals
 

Why are some crystals labeled AM and some FM? Aren't AM &FM methods of modulation and unaffected by crystals? Also, is the old pulse modulation a seperate form of modulation, or does it fall under AM or FM? I'm confused but trying to learn. Thanks

RE: Transmitter/receiver crystals
 

AM and FM use different crystals. PCM and PPM both use FM so they both use FM crystals. Then on the reciever side you need to make sure you get a single conversion or dual conversion crystal depending on the receiver type.

Here's some reading for you: http://www.torreypinesgulls.org/radios.htm