The Clear-Com IF4W4 modular 4-wire interface connects camera intercoms, two-way radios, fiber optic circuits, and other 4-wire devices to a standard Clear-Com intercom line. The 1-RU chassis holds up to four individual interface modules, each with its own 4-wire terminal block and XLR-3M connector to interface with Clear-Com. The IF4W4 accepts balanced or unbalanced 4-wire input and is transformer isolated. The Clear-Com intercom line powers it, using standard two-conductor shielded mic cable.Front-panel controls let you adjust the operating parameters for each interface module, optimizing the interface between the 4-wire device and the party line. You can adjust the transmit and receive levels between the intercom system and the 4-wire line, optimize the hybrid null balance, switch the transmit level between mic and line level, and emulate either a carbon or a dynamic microphone. A two-color LED transmit-level indicator gives you a visual indication of send levels to the transmit lines.A front-panel test jack is connected to a built-in oscillator. Using the null control and an earphone with a 1/8″ plug or 4-pin headset, you can quickly null the send/receive hybrid. Setup switches let you assign the interfaced devices to separate intercom channels, or to assign any or all to a single party line. Each interface module has its own set of transformer-isolated connectors. The terminal block provides a pair of connections for both transmit and receive signals, with a 600-ohm load across the receive line. An XLR-3M connector provides the link between the interface and the Clear-Com intercom line.Main Features: Interfaces TV cameras, 2-way radios, fiber-optic circuits, and other devices to Clear-Com party-line intercomEach interface has individual transmit, receive, and null controlsTransmit output switchable between mic and line level, with transmit-level indicatorBuilt-in test jack and oscillator enable quick nulling of the transmit/receive hybridSelective party-line capabilityAccepts balanced or unbalanced 4-wire inputTransformer isolatedTerminal block and XLR connectors provided for each interfacePowered by the Clear-Com line