Is the transmitter module used on the 9C transmitters interchangeable with those used in the 7 and 8u series of transmitters. If so is there a problem with substituting a module for channel 56 with a module for channel 24 on the 9C transmitters.

Bq, the modules are identical, and that's is exactly the idea of the modular system.s not only can you change within your band, but you could even put in a 75MHz band and use it for a robot, or a 35MHz and go fly in Europe!!