A few months ago there was a post about buddy boxes and the power switch on the slave box.
I swore up and down that the slave box power switch needs to be off.
I learned something new yesterday. My student is using the spread spectrum which of course is JR he bought a JR to Futaba buddy cord. The instructions for the cord states remove the crystal from the slave and turn the power switch on! The system didn't work with the slave switch off.
Happens that another student was having probs(flying JR) we loaned him our cord and our slave box....worked fine.
Sorry for any probs my lack of knowledge may have caused

Appears that JR likes to be a little different. That is why "I" feel students need to visit the flying field before the hobby shop, then they would know what brand of radio is prefered, and what training boxs and cord setups are needed. Our field is almost exclusively Futaba, Jr radios seem to take alot of stray hits. Could be magnetism, sun spots PCBs, railroad crossing signals who knows for some reason they get hit more often.
Luckly you found the work around to the problem and hopefuly your student is progressing nicely.

I haven't heard or seen that JR gets more hits. Sorry you guys are having that problem.
What I don't like about JR for a student is that the system is powered when the buddy cord is plugged in. Forget to pull the cord and you drain the batteries on the transmitter.
I also wish students would visit the local field before the hobby shop, then again some students dont listen to us, and have probs interfacing the buddy system.
My first student took his radio back and got Fatuba he got lucky there was a problem with the trainer switch. This was after he was told he may have problems with our equipment and any other brand besides Futaba.

Even in a field full of Futaba transmitters, the Hitec stuff is highly interchangable. Hitec radios are intentionally designed to be widely compatible with Futaba equipment, and buddy boxing a Hitec radio to a Futaba transmitter should be no more challenging than mating two Futabas.

It'd take quite a long time to drain the batteries that way. You'd have to leave it like that for a day or so. Why? Because the RF deck isn't powered when you've got a buddy cord (or other cord) plugged in. The RF deck uses a huge amount of power in proportion to the other components.

It's not an issue.

ACtually, my wife has left the cord into my JR Quattro (that I use as a buddy box) and it drained the freshly charged (only flown once on the day) 700 mah battery in just a couple of hours. We returned to fly hers again, and the battery was dead, and the tx had shut itself down.

So I can be a problem. Don't forget and leave it plugged in, or it will definitely shorten your student's day.

BTW, the Spektrum DX7 powers up the same way when a buddy cord is connected. The futaba to JR cord is a different animal all together.

Holy smokes, you're actually right. I'm thinking of pulling the module or crystal.

Hi guys, could you please advise, are there Futaba to JR to HiTec buddy training cords, as I was about to purchase a Futaba radio (6EXA) but thought I had better wait to see who will provide me with flight training, so I buy compatability. From what you have said in this forum, one group say check out your club for majority radios, and the other mentioned Fut to JR cords - what should I be doing - please?

The futaba to JR cords are uni-directional. They only allow information to be passed one way. By using this cord the JR must be the master and the futaba must be the slave. This would be fine if you go JR or Spektrum. In other words, if you decide to go with JR (or Spektrum) and your instructor only has Futaba as a buddy box, then buy the JR to futaba cord. Use your JR or Spektrum radio as the master, and his futaba as the slave. However, if you go with Futaba in your plane, and your instructor only has JR equipment, then you will be out of luck, as the cord doesn't work in reverse. But, you can generally get a compatible buddy box for around 50 bucks if you had to. I think it boils down to personal preference.

At least, that is how the cord worked when it was first introduced. There may be something new out there that I'm unaware of. If so, I'm SURE someone will jump all over me, yelling about how WRONG I am.

Thanks for the info on this as I want the spectrum DX7 for a radio and most at the Field use Futaba. This will work for me, but I will ask tonight a the club meeting if the trainer is there.

Thanks
John

When the buddy cord is plugged into the JR transmitter only 70mA (approx) is used, where without it approx. 200mA is drawn. Therefore with the buddy lead plugged in you should get approaching 10 hours of use.