- The interfacing requirements to the two-way radio are also simple, requiring a minimum of 6 connections, namely...
1. 10-30V DC power @ 50ma
2. Ground
3. PTT to the transceiver
4. Busy / Mute indication from the Transceiver
5. Modem audio to the Transceiver (post pre-emphasis)
6. Discriminator audio from the Transceiver (i.e. pre de-emphasis)