The KB-212 remote speaker station connects to a single channel of party-line intercom, and operates in half-duplex mode, similar to a walkie-talkie. It features both an integral speaker and a flush-mount electret microphone with mic limiter and a push-to-talk button. The station may be programmed via two internal dip switches to operate in four different modes, activated by other stations within the intercom system.
The different operating modes are activated using the call signaling function of another station, which allows for individual control of the speaker and microphone. The default mode is speaker on/mic off, with push-to-talk active on the front panel. In the remote page mode, the mic is activated locally and the speaker is off except when turned on by another station. For remote push-to-talk, the speaker is on and mic is off, unless it is turned on by another station. And in the talk-back remote page mode, the mic is normally on for hands-free talking and the speaker is off; another station can turn off the microphone and turn on the speaker for paging to the KB-212.
Microprocessor-controlled logic and switching yields a feature-rich intercom station in a compact format. An electronic momentary-only talk button activates the talk function. A green LED indicator lights whenever the mic is activated, either by the talk button or by remote control from another station. Mic sensitivity is selectable for either close or distant voice pickup.
The KB-212 offers both visual and audible call signaling, gaining the attention of the
user when not at the station. A bright yellow LED lights when a call is activated on a connected intercom channel. A defeatable audible call signal, with level control, is also provided.
Separate level controls are provided for intercom level and for balanced program input. A local program source may be fed to the station, allowing the user to monitor that source while remaining in contact on the intercom system. The balanced program input can also be used in conjunction with the stage-announce output of a main station to provide a paging interrupt. This would allow paging at the station even if the intercom volume control is turned down. In addition, the intercom volume control of the KB-212 can be internally set so that an incoming message would still be audible, even if the control was turned all the way down.
The KB-212 may be wall or console mounted in a standard 4-gang electrical box, or
may be mounted in the optional V-Box for desktop, surface-mount, or portable applications. It may be used with the optional 4-wire or TW (two channels on a single mic cable) daughter boards. The station is powered by the intercom line or by a local power supply when used with the optional 4-wire daughter board.