Clear-Com EF-701M Interface

The EF-701M bridges a single channel of standard or TW partyline intercom to four-wire audio, and it converts the partyline call signal to and from RS-422 data at the same time. That combination lets a Clear-Com channel reach a matrix port, a fiber-optic modem, or a second EF-701M across ordinary twisted-pair such as CAT-5E, carrying both voice and call signalling over the run.

The interface holds a stable hybrid null even with several units on one channel, so partyline audio stays clean as the system grows. The rear panel carries an XLR3F partyline port, a DB-15F RTS port, and an RJ-45 for the four-wire and data link. It draws its power from a 20 to 30V DC source and is a standard building block for tying a partyline into a larger matrix or fiber plant.