JR642 Interface - Signal for 2.5 seconds only! - JR642 Interface - Signal for 2.5 seconds only!

[steves]

Help. I have built a simple JR interface with a low pass filter (from Wayne Tarr circuit in previous posts). Problem is I get no signal - except when I have the transmitter off and plug in the cable, this powers up the transmitter and sends a single for 2.5 seconds (if you are in calibrate the channels go all over the place). I suspect this is the transmitter trying to talk to the other transmitter in buddy box'ing mode. From this I think the circuit is working and suspect the transmitter is not sending for some reason.

Anyone any ideas? Any particular mode I should set the transmitter to? Could it be because I don't have a crystal in the transmitter at the moment (but logic says the RF side shouldn't matter).

P.S. I'm an electronics engineer, but new to radio control.

[bsergeev]

Wayne Tarr circuit works fine for Futaba transmitters--it reduces the jitter, present with all Futaba-s I've tested.
When I tried Mr. Tarr circuit with my JR, it didn't work at all!
The diagram found here

worked fine for me.

Also, you may want to try Steve Lewin serial cable modification: read the recent discussion here:
[url=http://cgi.ethz.ch/~mmoeller/cgi-bin/ikonboard/topic.cgi?forum=2&topic=23

Good]http://cgi.ethz.ch/~mmoell....

Good[/url] luck,
Boris