Anyone know whether the pots in the Tx are used in "variable voltage
out" form or "variable resistance" form to control the channels? I
presume, due to 3 wire connection that its the former but id be pleased

if someone could confirm? I'm trying to modify one to accept inputs
from something else so that i dont have to make my own transmitter
circuit but I'm struggling to find information about it online.

TIA
J

Usually as the resistance varies so does the voltage.

Well this is how i would have assumed but I'm told i maybe barking up
the wrong tree and it may be part of the transmitter signal modulation
circuitry and not a simple pd divider. I'll get the scope on it.