What is the difference between a regular transmitter and a PCM transmitter?

Check out www.torreypinesgulls.org/Radios.htm for a good explanation.

Today most computerized radios are both. You just need the appropriate reciever. And make sure the model you are fling's programming is set the the correct modulation. The older ones are one or the other. I will not try to explain the difference. It is basicly the way information is transmitted. Pcm is sent digitally using pulsed FM. PPM is not digital. That is the way I understand it.

Mark Shuman

I'll second Rodney's recommendation to look at that Tory Pines link. It's the best article on how our gear works that I've ever seen. It should be "manditory" reading for anyone who wants to have a real clue about what's going on.