Could someone please explain the difference between pcm and fm? Advantages, disadvantages, etc.

Thanks

Greg

PCM is better in that it will detect a loss of signal and tell the servos to remain the same for a while. FM gets a bad signal for a few milliseconds and passes this bad info along to the servos. So the servos glitch. When both are working, there is really no difference. But if the signal is weak, PCM will appear to be better. Some would argue that they would rather see the glitches that FM passes along. PCM can mask intermittent failures of signal.

And PCM is a form of FM. Both are frequency modulated, but PCM layers a digital encoding on the fm transmission.

PCM IS FM.....

the better question would be the difference between PPM and PCM.....

they are both FM

exeter_acres,
Thank you for pointing that out. I was going to say the exact same thing.

Ken

thanks to all for the info

FM Frequency modulation.........the tops of the waves are realtively constant, the wavelengths change

PCM.......using frequency modulation, you can essentially send a square wave signal.....square wave signals are great at xmitting digital code.........therefore each pulse can have a uniqie binary code preceeding the pulse......the code identifies your xmitter............the reciever ignores all signals that do not have the proper numerical digital pre-code attached to each pulse. B52 go-no go technology.

PPM....I don't know what that is

PPM is Fm.