is there any problems or ill effects from using a Tx with a different brand Rx.

Yes and no.

Some brands are compatible and some are not.

Provided that it works, no. 72mhz PPM (FM) is really quite flexible. So long as the phase shift of the receiver and transmitter are the same (they're either positive or negative), you're good to go.

PCM and 2.4ghz gear aren't interchangeable between brands.

i have a futaba T4EXA, so if the rx says its compatible with futaba everything is ok, or is it just better to stay with a futaba rx. thanks for the replies.

If the Rx says it's compatible with Futaba, you're good to go.

Many brands of receiver will work well with that transmitter, most Hitec, Corona, FMA, Berg and.......on and on. As long as they are PPM and negative shift (or selectable shift) they will work.

thanks for the info, happy flyin.

If you tell us what manufacturers and what model of radios you are talking about we can be more specific. Right now the answer must be: Yes, no and maybe.