JR Buddy Box
 

Our R/C club has been providing a training night, at our club field, every Tuesday night, from May-Sept, for many years. We usually have 5 or 6 trainers and 5-10 trainees, depending upon the weather.

We have a club training plane, that was donated, and is equipped with a JR Quatrro radio and a JR Quatro Buddy Box. We also have a JR 421 radio that we can use as a Buddy Box. Recently, we had a trainee come out with his trainer plane and a JR 421 radio. We were unable to get the Quatrro Buddy Box or the 421 radio to work as a Buddy Box. When we connected the 421 to the 421, we got power to the Buddy Box, but none of the controls would work. We have had similiar experiences with other redios.

The local hobby shop used a JR 8103 as a Buddy Box for the JR 421, and it worked. He said that the Buddy Box jack was not broken.

Is there any literature that helps define which JR radios can be used as a Buddy Box and with which JR radios that Buddy Box is compatible?

I am not familiar enough with JR radios as I have had Futaba, for years, however, I have a JR 8103 that I am learning to program. I have run in to issues with trying to use Non-Programmable Futaba radios as a Buddy Box for a Futaba Programmable radio. Usually, you get connectivity, but the Non-Programmable Buddy Box will only work with the High rates on the Master or there is an issue with the Trim. Either way, it renders the Buddy Box unusable. Using the same radio as the Buddy Box and the Master, will always work.

RE: JR Buddy Box
 

Hi,

The manual of the JR 421 says this on page 9 :
quote
The XF421EX features a built-in trainer system. The transmitter can be used as either a master (trainer) or as a slave (trainee). The XF421EX is compatible with all other current JR radios that have built-in trainer systems. An optional trainer cord is needed.
1. Match the servo reversing, sub-trims, travel adjust and trims of both radios.
2. Plug the optional trainer cord into both transmitters.
3. Turn on the master transmitter. (Note: The slave radio must be left off.)
4. Test all the control functions on your aircraft with the master radio.
5. Push the trainer button on the master transmitter and check all the control functions with the slave radio.
unquote
Just a remark : master transmitter MUST be switched on, even if the buddy cord switches on the transmitter (but disable the HF-part)

The manual of the JR Quattro says this on page 12 :
quote :
The Quattro features a built-in trainer system. The transmitter can be used as either a master (trainer) or as a slave (trainee). The Quattro is compatible with all other current PPM selectable (FM) J-line or JR radios that have built-in trainer systems. An optional trainer cord is needed (JRPA130).
1. Match the servo reversing and trims of both radios.
2. Plug the optional trainer cord into both transmitters.
3. Turn ON the master transmitter. NOTE: The slave radio must be left OFF.
4. Test all the control functions on your aircraft with the master radio.
5. Push the trainer button on the master transmitter and check all the control functions with the slave radio.
unquote

So there should be no problem between 2 JR like the JR421 and/or Quattro
I suppose both 421 where in PPM-mode (if PCM ever available on this TX)?
Possibly a fault in the trainer switch of the master transmitter?

[link=http://users.belgacom.net/TX2TX]My website[/link] is about buddy box systems, but unfortunately I have no personal experience with JR.
Happy learnings...be patient with the "poor" beginner !
Olivier