Hello
Pardon a rcuniverse newbie for jumping in.
I faced asimilar problem as the OP and I'm working to create a device to sendmultiple proportional, independent channels over one radio channel. Iadd a small circuit to modify the PPM stream in the transmitter andanother circuit connects to the receiver. I don't think the latesttransmitters (that don't use PPM internally) can use this solutionwithout jacking into the trainer port.
So far I've demonstrated controlling 6 extra channels and I've made a receiver (or rather, "demux") prototype with 9 outputs.
I only started talking about the project two weeks ago:
http://www.rcgroups.com/forums/showthread.php?t=1341590
As you can clearly see this is just a hobby project, but my goal is stillto make a generic product that will work with as many systems aspossible and to make a batch for the public. So far I've tested withFutaba 9C with both Spektrum module and DragonLink long-range system.While doing it all from scratch is time-consuming, it makes a lot ofdifferent functionality possible.
I can't offer the OP anything at the moment but I'd still like to hear about any interest or suggestions in the mean time.
Regards
Kiwi