The end-of-transmission signal (Roger) – In simplex mode operation, operators, upon completing a message, often use the phrase: "switching to receive" or simply "over", thereby indicating to the correspondent that they will now switch the radio to receive mode. Many modern radio transceivers have a function for automatically transmitting a short audio tone indicating the end of the transmission process and the deactivation of the transmitter, known as the Roger signal. This signal can be a single tone or a combination of two or three tones.
The Roger tone may also accompany the start of voice transmission. That is, when you press the push-to-talk button, the channel first transmits the ROGER TONE, notifying everyone that you intend to make a transmission.