Model Forum / Radio Controlled / Air Models / November 2007

swap the transmitters and let the pupil use xf421  ???

It's not just JR and Hitec -- it's all the lower end master TXs.  And
it's `no interpetation at all' rather than `not much interpetation'.

Generally, what happens is that each (master and buddy) TX takes all
it's gimbal positions, all it's switches and mixes and such and comes
up with a final PPM signal, one for each TX.

If the trainer switch is engaged, the PPM signal from the buddy box is
transmitted.  If not, it's the PPM signal from the master.  Signals
from the two boxes are never mixed, and the master never mixes the
slave's channels in any way.

A few of the higher end transmitters can decode the signal from the
buddy box, and then use that signal to replace a few of it's
gimbal/switch inputs if the training switch is engaged, and then run
that through it's mixers and transmit the resulting signal.  I know
the Futaba 9C and I think the Multiplex Evo 9 have this feature, and
newer models of those lines probably have it too.  I don't think any
Hitec radios have it, and I imagine that the fancier JR radios do, but
I don't know for sure.

Older/cheaper TXs of all models do NOT have this feature.  But if you
have a TX that does, you can use it as the master, and just use a
basic 4 channel buddy box with no programming capability as the slave.