RC Basics

An RC aircraft radio system consists of a transmitter, receiver, servos and a

battery. If it's an electric powered plane it will also have an ESC.

Transmitter(Tx): -Hand held controller that sends the pilots inputs to the aircraft.

Receiver(Rx): - Electronic unit that rides in the aircraft. Receives signals from the transmitter and relays these signals to the servos.

Servos: -Small proportional controlled gear motors that mechanically move the control surfaces on the aircraft. Servos are plugged into the receiver where they receives input signals from the pilot.

Batteries: -Both the receiver and the transmitter require a battery pack to operate. The battery packs usually consist of Lipo ( lithium-polymar batteries.

Electronic Speed Controller: - Plugs in to the throttle port of the receiver and controls the speed of the motor of an electric aircraft.


How RC Radios Works

The transmitter converts the pilot's movements into a radio signal in a process called modulation.

The transmitter then broadcasts this signal to the receiver.

The receiver inside the aircraft picks up this signal the same way the radio in your car picks up the local

radio station. The receiver pulls the information from the radio waves and relays this information to each servo.


Each servo has a horn that is attached to its shaft. This horn is attached to a control surface, or engine throttle,

via a push rod. The rotation of the horn translates into a linear movement at the control surfaces.

The movement of the servo is directly proportional to the movement of the control sticks on the transmitter. In other words, the control surfaces on the aircraftmove exactly the way you move the stick on the transmitter.


The servos and receiver battery simply plug into the receiver. Most people add a switch between

the battery and receiver which is mounted to the side of the aircraft.


The switch allows you to turn the receiver off without removing the battery when you're not flying.

A switch with a charging harness allows you to charge the battery without removing it.

Wairarapa Model Aero Club