27MHz

The Radio Frequency Used in RC Vehicles

Father and son playing with RC toy car
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When it comes to operating radio-controlled (RC) vehicles, frequency is the specific radio signal sent from the transmitter to the receiver to control the vehicle. Megahertz, abbreviated MHz (or sometimes Mhz or mhz), is the measurement used to describe frequencies.

The Federal Communications Commission (FCC) has allocated certain frequencies for consumer use for items like walkie-talkies, garage door openers, and RC toys.

Most toy-grade RC vehicles operate at either 27 MHz or 49 MHz. The more sophisticated toys run by advanced users operate at 72-MHz or 75-MHz frequencies. 

What's the Frequency?

27 MHz is the most common frequency used in radio controlled vehicles. The manufacturers of these toys will always clearly list the frequencies at which they operate, and they often make the same toy  at both 27 MHz and 49 MHz. That's because if the hobbyist wants to race or run two cars at the same time, they must operate on the same frequency. Otherwise, the transmissions will "jam" or crosstalk, and the cars won't operate properly.

Bands on the Run

There are several bands or channels within a specific frequency that are commonly used and these may vary by country or region.

In the U.S., 27MHz (with up to 6 color-coded channels) is commonly used in both hobby-grade and toy-grade RC vehicles.

Those frequencies are:

  • 26.995 MHz -- Channel 1 (Brown)
  • 27.045 MHz -- Channel 2 (Red)
  • 27.095 MHz -- Channel 3 (Orange)
  • 27.145 MHz -- Channel 4 (Yellow)
  • 27.195 MHz -- Channel 5 (Green)
  • 27.255 MHz -- Channel 6 (Blue)

In Australia, 27 MHz Channels 10-36 are for surface vehicles. In the UK, 27 MHz (13 color-coded channels) is used for some RC toys.

Kick Out the Jam

In many toy-grade vehicles the specific channel within the 27 MHz range is not specified and is unchangeable, making it more likely that two or more 27 MHz vehicles operating in the same area will experience crosstalk or interference.

The most common fixed frequency for 27 MHz toys is channel 4 (yellow) at 27.145 MHz. RC toys with selectable bands (usually 3 or 6) generally have a selector switch on both the vehicle and the controller that let the operator select a different band or channel (designated by letter, number, or color) so that two 27 MHz toys can play together.

Smooth Sailing

So how does the transmitter, operating on a frequency, actually work? Whenever the operator presses the button, trigger, or joy stick on the vehicle, a pair of electrical contacts touch, completing an integrated circuit. This circuit causes the transmitter to send a set sequence of electrical pulses to the receiver, and the number of these pulses sets up a series of actions. On single-function toys, these pulses propel the vehicle forward and backward, while full-function toys can also turn to the left or right when moving both forward and backward.