whats the difference

[racerx217]

i am looking at buying one of the high end futaba radios but what is the difference between PCM and FM?

[Duster_360]

Not sure of the tech details, but the FM type is the earliest mode of FM modulation, while PCM (pulse code modulation) is a later development and better mode of FM modulation. Modulation has to do with how the signal is encoded and carries information to the receiver. The lastest Futaba chapter in this is HRS_FM, high response speed. The later forms are better - faster response and less interference. HRS requires use of digital servos only and is a more expensive proposition.

I have a 3PK, one of Futaba high end radios and love it - single radio, runs 6 rcs (and counting - soon to be 7). Takes a little getting used to, but you pick it up real quick.

[asw7576]

Good move. You should buy HRS FM instead PCM or FM receivers. I have those three kinds, the fastest response is HRS and later is PCM and FM Rcvr.

With HRS FM, you must use digital servo only !!!

With PCM rcvr, any servo will do including digital servo, but the response is not optimum.

[highroller]

PCM varies the modulation a bit than FM. For racing where most are now using some sort of FM transmitter I like the PCM (3PJS or 3PK) mode.

I prefer to use PCM mode over standard FM for me it helped eliminate some of the freqeuncy overlap when you have racers near your freqency with just the FM mode on.