Futaba buddy box... Confused...

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Futaba buddy box... Confused...

Postby hohocc » Mon Nov 19, 2012 11:23 pm

My primary tx is a Futaba 7UAPS (35mhz PCM), and I've borrowed a 7CHP (72mhz PCM) from a friend. So far so good.
Links to the two manuals are:
7UAPS http://manuals.hobbico.com/fut/7uafs-7uaps-manual.pdf
7CHP http://manuals.hobbico.com/fut/7c-manual.pdf
Trying to link them together with the 7UAPS as master and 7CHP as student. UAPS has round trainer port, CHP later square, no problem as the leads that came with Phoenix flight sim are able to link the two.
7UAPS manual P40 says BOTH txs must be on the same modulation (PPM/PCM). The rx in the model is PCM so I must have PCM selected on master or model will not recieve any signal.
7C manual P10 states the 7C is compatible with many other Futaba txs via a trainer cord, and square to round cords are available, think I have this covered with the sim cords.
7C manual P38 says the 7C is compatible with any Futaba FM tx compatible with the cord, it also says the student modulation must be set to PPM.
I'm unable to get any reaction from the model with the txs linked using the student (7C) tx, all works as normal from the master tx.
With one tx being 35 and the other 72mhz, I had not thought this would be a problem as the student tx stays switched off, maybe it is?
I've tried the student (7C) tx in pcm and still no luck, suspect the ppm/pcm thing may be a good part of the problem.
Am I flogging a dead horse or have I missed something obvious?
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Re: Futaba buddy box... Confused...

Postby ergocentric » Wed Nov 21, 2012 5:11 am

What cable are you using?

A flight sim cable probably won't work. It will only allow signal in one direction, 50% wrong.
You will need to switch on both radios as a flight sim cable has no power wires.
(batteries in, you can remove the crystal from the student radio to stop it from transmitting)

http://users.belgacom.net/TX2TX/tx2tx/e ... 2txgb7.htm
unconcerned but not indifferent - MAN RAY
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Re: Futaba buddy box... Confused...

Postby hohocc » Thu Nov 22, 2012 6:49 am

Thanks for the info, it did seem too good to be true to get away without buying a trainer cable!
Will order the right thing and be done with it.
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