In RC vehicles, frequency is the specific radio signal sent from the transmitter to the receiver to control the vehicle. Hertz (Hz) or megahertz (MHz) or gigahertz (GHz) is the measurement used to describe frequency. The most common frequencies in the US for radio controlled vehicles are 27MHz, 49MHz, 50MHz, 72MHz, and 75MHz. There are anywhere from 6 to 50 channels within each of these frequencies. There are a much larger number of frequency channels within the 2.4GHz range.
While other frequencies require that a specific channel be selected (through the use of crystal sets), special software within the receiver and transmitter of a 2.4GHz DSM radio system work to set the specific frequency channel within the very wide 2.4GHz range, locking out interference from other systems operating within the 2.4GHz range in your operating area. There is no need to change out crystals or select specific channels yourself. The transmitter/receiver do it for you.
The DSM transmitters/receivers using the 2.4GHz frequency range can be used in many countries, including the US and are found with both surface and air vehicles.
