can and where could a feller buy a add on channel for a radio system to poor to buy a new radio system ....just need a extra channel don,t care if it,s a diffrent Freq........either..thanks for any info ...Dave

not really unless you mean a reciever.check the rcu marketplace for used tx/rx

You may have to come up with some mix to activate the extra function you want.
I assume you are after an additional function in your plane.

There are no add ons for your Tx that I have ever heard of, but maybe you could pick up some ones old 4 channel for next to nothing.
Then you will need another Rx for that. Things start to get messy.

Depending no what you are trying to do a device called Channel 3 from [link=http://www.oregonscaleaviation.com]Oregon Scale Aviation[/link] might help.

Chris