PCM is abbr. for Pulse Code Modulation
An electronic encoded signal that helps minimize the effects of interference better than PPM (FM). When in the PCM transmitter mode; and of course with a PCM reciever; you have the option of setting fail safe.....if you do loose your signal the plane will automatically go into its failsafe settings which you decide. Exam. Throttle to idle, control surfaces to level or set it to turn circles...whatever you input.
Futaba 7CAP or 9CAP are both good choices and under $300.00. I got my 9CAPS from
http://www.servocity.com for $289.95 with the 16k module (14 model memory), frequency module and a couple of more handy items tossed in. No servo's
$149.00 there for 7CA, thats a no servo's price. $279.95 with the 4 S3151's. $249.95 with S3004's or you may select what you want with your TX there and get a quote.
I like Tower and Servo City. I do not sponser either just typically cheaper at servocity and sevice has been excellent for me.
JR is a good choice to, but I think best to stick with what your club is mostly using. Trainer cord, help in set-up, etc. Need to look at what cord the club has for trainer if you are just starting. The new is square but just two years back they were all round connections. Most clubs have a set-up for both.
Michael