As you move into more advanced types of rc airplanes and rc helicopters. The electric rc airplane radio that came with your basic trainer was likely a 3 or 4 channel model that operates on either 27 or 72 megahertz (MHz). 27 MHz is often used in lower-cost airplanes and it works ok, but it is subject to interference from CB-band radios. The 72 MHz band is divided into 49 channels from Channel 11- Channel 60 and is reserved for rc aircraft (it is illegal to use these radios for boats or cars). So if you really enjoy flying rc airplanes, then a dedicated electric rc airplane radio is the way to go.
There are brand- name choices; JR, Futaba, HiTec, Airtronics and prices from $139 to over $2000!! Which one you select should depend on several factors. If you’ll be a flying at a local club’s field – highly recommended – then ask the members what radios and channels they are using for the flight instruction program. You’ll want to be sure that you and your instructor have compatible equipment, because during training, you will link your radio to his so that he can take over to avoid an unplanned meeting with mother earth! The second factor is to select a radio model that will allow you to fly more complex aircraft as you progress in the hobby. That p-51 mustang with flaps and retractible landing gear will require a 6 or 7 channel radio, so consider spending a little more now.
Knowing this, you might decide to pick a basic trainer that includes a 4+ channel radio system, so that you don’t have to immediately buy another one. It is possible and practical to have one radio transmitter with several receivers in different rc airplanes. They will operate on the same frequency and if your radio can accomodate them, the settings for each plane can be stored within the transmitter. This way, when you get a new airplane, you just buy another “flight pack” which includes the servos and receiver.
Every rc pilot has favorite radio systems, some excellent pilots use the most basic radios with considerable skill, others prefer the latest computer programmable “whiz-bang” models. My own preferences include both JR and Futaba with storage for up to 32(!!) model settings, but a favorite electric rc airplane radio of mine is an older Futaba 6-channel with no memory or computer settings, that just keeps on with a big (72″ wingspan) electric Piper Cub!