Chapter 7. - DTMF
DTMF is an in-band signaling method using dual sinusoidal signals for any given code. Originally
developed for telephony systems, it has proved a very versatile tool in many other areas.
In two-way radio systems, DTMF is most commonly used for automation systems and remote
control. A common example would be in amateur radio repeaters where some repeaters are
activated by sending out a DTMF sequence (usually a simple single-digit sequence).
Table 7.1. DTMF frequencies and corresponding codes
The BaoFeng BF-F8HP has a full implementation of DTMF, including the A, B, C and D codes.
The numerical keys, as well as the , and , keys correspond to the matching DTMF codes as