Telex EMS-4001 Intercom Expansion Station

The EMS-4001 adds four fully powered intercom channels to a Telex Audiocom system, each with its own talk, listen, and call controls and back-lit function buttons in a single 1U rack unit. It carries a built-in 2.0-amp system power supply, so the four new channels arrive powered rather than borrowing current from the master station. Selectable voice-activation controls and separate speaker level controls let an operator shape each channel.

Every expansion channel has a dedicated rear-panel program input on a DB-9F connector, so any line-level source can be monitored in the station speaker or headset and routed onto the channel. It connects directly to an MS-2002, MS-4002, or US-2002 master station, or chains to another EMS-4001 or ES-4000A to build systems up to 22 channels. Automatic current limiting protects each channel during a short or overload, with a front-panel fault indicator per channel, and four RCA speaker output jacks feed local monitoring.