The EF-701M interface converts a single channel of standard or TW party line intercom to four-wire audio, while also converting call signals to RS-422 data (and back).

The EF-701M interface converts a single channel of standard or TW party line intercom to four-wire audio, while also converting call signals to RS-422 data (and back). The resulting four-wire audio plus RS-422 data can then be sent to a Clear-Com Matrix port, ber-optic converter (modem) or connected to another EF-701M over twisted-pair cable such as CAT-5E. When used with a Matrix system, the EF-701M allows a party-line channel to be connected to the frame with up to 5000 feet of cable. With its excellent hybrid null and wide-range level controls the unit may also be used as a best-quality stand-alone two-to-four-wire converter.

For travelling systems that require long connecting runs between stations or systems, EF-701M’s can quickly recover their cost in space and weight savings, as ber-optic and UTP cables are lighter and more compact than standard shielded mic cable. Two EF-701M’s can be connected directly to each other over low-cost four-pair, unshielded, twisted-pair cable (UTP). The EF-701M ’s low prole and compact size add to its portability. It can easily be mounted on a utility rack shelf and up to three units will t across in a standard 1-RU rack space. No additional power connection is required, as the EF-701M obtains its DC operating current through the party-line connection on pin-2 of the XLR connector.