It relies on the fact that almost every ham radio designed for field use incorporates a DTMF encoder in the microphone or in the transceiver itself.

ANI encoders and decoders using APCO P25, MDC-1200, Fleetsync, GE-Star and DTMF formats are available for portable and mobile transceivers as well as desktop, console and multi-channel rack mount ...

The NCTx and NCRx family of Encoders and Decoders require little setup and the local control panel is easy and user friendly. Simply apply video, power, connect and select a preset.

His DTMF decoder box uses a CM8870 DTMF decoder chip, which you might assume is all you need to get the job done.

The AMBE-3003 Vocoder Chip offers three separate encoder/decoder operations to enable up to three full-duplex channels. With 62 built-in voice/FEC rates, designers can easily configure the chip to ...