olivier

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