R/C Transmitters

Basics of R/C Transmitters and Receivers.

Transmitters and Receivers

Basically the transmitter (Tx) sends a radio signal to a receiver (Rx) and the receiver passes that information along to the devices in the R/C model (droid in our case).

Transmitters (Tx) are paired with their receiver (Rx). Often they are sold as a set. Many systems are similar and sometimes receivers can be used with different transmitters, but make sure you get a compatible receiver for your transmitter, especially if you have to replace it.

Anything with a transmitter and receiver can be used to control things (well, there may be laws about what frequencies can be used for what), and the terms "transmitter" and "receiver" aren't restricted to R/C cars. Your automatic garage door opening remote is a transmitter and the box in the garage has a receiver.

Transmitter types

I'm going to overgeneralize, but hobby transmitters come in two basic forms:

Car transmitter.

Sort of a gun shape with a wheel on it and a trigger. The wheel steers the car and the trigger controls it's speed.

Airplane transmitter.

This typically has two joysticks, one for the left hand and one for the right hand. Each stick can usually move forward, backward & left & right. They'll try to center themselves, except for one of the forward/backward sticks, which won't have the springs. This is the throttle of an airplane. Interestingly, the controls are different in the US from most of the rest of the world, known as "Mode 1" and "Mode 2". Make sure you're buying the expected kind of transmitter!

-Mode I transmitter right forward/back stick won't return to center.

-Most II transmitter's left forward/back stick won't return to center. Used by most US R/C pilots.

Some transmitters can have the springs removed/added if desired.

Channels

Pairing

Modern transmitters share the same frequency, so you have to tell the receiver which transmitter to listen to. This is called pairing, like pairing a Bluetooth.

Check your manual, but to pair, usually you do something like plug a special jumper into the receiver (don't lose it!) and push a button on the transmitter.

Frequencies

R/C transmitters use frequencies assigned by government regulators. Some countries require operational licenses or restrictions that are beyond the scope of this page. Please make sure you follow the regulations for your location.

Toy R/C cars typically use the 29Mhz or 49Mhz frequencies and are relatively simple systems that can easily interfere with each other. So 2 kid's cars can steer eachother and cause all sorts of havoc. We tend to want to avoid that sort of thing when we might be hanging out with other droids.

Modern hobby R/C transmitters use the 2.4Ghz range and have special DSM software that prevents most interference. You really want to make sure you're using one of these newer radios.

Older transmitters had assignable frequencies, by changing the "crystal" used for the transmitter and receiver, but there can still be conflicts. Few newer hobby radios use this technology anymore.

Sound remotes

These aren't really R/C type remotes, but many droid builders use a 12 channel type system commonly found on Amazon or ebay.

Note that these additional 12 channel type sound transmitter many droid builders use can also interfere with each other. Often they can be assigned to different settings, so if you start hearing sound from your droid (or your neighbors), check if your sound remote can be reconfigured.

More Info

We have a page about the Turnigy9X transmitter

We also have a page about Airplane RC assignments.

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