Bad_Daddy

A buddy of mine has 2 DX6 radios and wanted me to show him how to set them up in Master / Trainer mode. Try as we might, the "trainer" box would NOT control any surface or the throttle. It actually seemed like the "Training" button on the "Master" radio was not working. Then, as a lark, I threw a voltmeter on his brand-new $16 trainer cable and now I'm really confused.
The cable has a 1/8" dia stereo plug on each end. The base of each plug is conductive to the base of the other plug, BUT the tip of each plug is connected to the middle of the opposite plug. Is that right???
I'd presume they should be wired tip-to-tip, middle-to-middle, base-to-base. The plugs are molded to the cable, so there is no way he could have switched anything up. Would you please run a continuity test on a good one and tell me the results? [&:]

bruce88123

This is NOT supposed to be a stereo plug. It is a mono-plug system with a 2 wire cable. If using a stereo plug system, where did you get it? This is probably your problem.
http://www.jrradios.com/Products/Def...ProdID=JRPA130
You can see in the photo that this is a mono plug.

Bad_Daddy

That can't be right, because we went to Radio Shack today and bought a simple male - male 6' stereo extension (for $6) and voila! the trainer system works just fine! In fact, we flew his Vista sailplane for over an hour today, I was on the master, he was on the trainer box.
An interesting note is that when we plugged the simple stereo cable in, as soon as the master was switched on, the display read "TRN", which it never did with the fubar cable.
I think JR uses a mono cable, but I thought the DX6 is 3mm stereo. At least the stereo jacks fit both of his units. Are some transmitter boxes wired differently than others, but both are marked "DX6" ??
Well, even if it is supposed to be a mono cable, the wiring should STILL be tip-tip, right? My guess is that maybe the jacks are mono, but with the tip / middle wires swapped around, the cable is effectively grounded out anyway.

Bad_Daddy

On "another RC Forum", I was informed the DX6 is a revamped JR 662.

So now, I stand informed!
Since JR is mono and the trainer systems are compatible between the Spektrum and JR radios, the mono cable would have worked, and the jerk at the hobby shop sold my buddy the entirely wrong cable - and that wrong cable happens to be cross-wired anyway. I know I'm not going to spend another dime at that LHS, and I'll do my best to convince him too.
With my thanks for setting me straight, I just decided to pass the info on to any of you who were interested.

bruce88123

All JR and Spektrum trainer cables use MONO plugs. I don't know the source of the first cable you purchased. Was it in JR packaging or just loose or other packaging? The fact that it had stereo plugs tells ME that it was NOT mfg by JR/Spektrum. This means the LHS utilized a third source of some kind. I have no idea why the the wiring was cross-wired. If possible simply try to get your money back for it and call it a day. Sometimes an apparent bargain isn't.

Glad you got it all working now. Watch your batteries now.

Bad_Daddy

Bruce, while you're here I have another question. I received a JR model S400 Trainer Box from the AMA when I (re-)joined last year. It looks like a Quatro case, with all of the frequency transmission circuitry removed, but it does have a D.S.C. jack and trainer cable with it. That cable is a mono cable, but I never thought about using it for our previous DX6 problem.
Anyway, the question is, can this trainer box be used with a DX6 as the master? Obviously it would need to be a simple 4-channel plane, with no mixes and so forth, but would it work?

bruce88123

To the best of my knowledge it should. Definitely won't hurt to try. I don't think you'll be able to use any mixes or expo's or D/R's on the master though. Remember to put in a battery and give it a try. Let us know for sure. As far as I know all that comes through the cable is a serial data stream.

As our buddy Paris would say "It's the simple life"