Young-RCPilot

Hello, I was wondering if I can use a standard FM reciever with the new JR 9303 because I don't want to put a PCM reciever in my 40 sized planes and electric foamy I would rather go with a small cheap FM reciever like Hitec Micro 4 channel reciever for my foamy. And the 9303 says its S-PCM and PCM and not FM.

bhanley

Look again (modulation screen on the system menu). It says SPCM and PPM. PPM is what you want.

Young-RCPilot

So is PPM the same thing as FM and also whats the diffrence.

bhanley

They both transmit in FM (frequency modulation) as opposed to AM (amplitude modulation). There are AM radios around but yours is FM. A simple minded answer to your question is that one, PPM, indicates servo position with an analog value and the other, PCM, indicates servo position with a digital value. There is of course more to it and if you are really interested there is a paper on the Torrey Pines Gulls web site that will answer all your questions. It is titled "Everything You Never Wanted To Know About Radios". Here's the link http://www.torreypinesgulls.org/
Good Luck

Young-RCPilot

Thanks for the help I was also windering if I can use a different FM reciever with the radio like a Hitec one.

bhanley

Not sure as I only use JR. However, I don't think so. JR and Airtronics use the same encoding (believe it is positive shift) for the pulse stream from Tx to Rx while Futaba, Hitec and Tower use a different encoding (negative shift). I may have the positive/negative backwards. So, you should be able to use Airtronics receivers with your Tx but not the others.

lrb75

My Feedback: (12)

Hitec makes each one of their receivers for both pos and neg shift or is capable of being switched from pos to neg with a jumper. Just make sure you buy the one for JR which is pos shift.