What kind of transmitter are you using for manual control? I assume you aren't using a ground station all the time...

I only ask because most new 'brand name' (JR, Futaba, Airtronics, Robbe) tramsitters seem to be 2.4Ghz. I know FM radios are still available on 36 and 40 Mhz, among others, but I haven't seen many used for a while with new aircraft.