The WMS-300L Wall Mount Speaker Station is part of a series of user stations especially designed to work within the TW (Two-Wire) Intercom System. It fits directly into a standard 4-gang electrical conduit box (2.25 inch deep). The rear section is not enclosed and uses the back-box to provide a housing when installed.
This user station is perfect for permanent installations where a wall-mounted station can provide an unobtrusive operating position. Most often it is located where the operator can conveniently attend to on-going operations while wearing a headset or listening to the loudspeaker. Typically, the WMS-300L is a very practical user station since it can operate in an open-listening mode with the panel-mounted loudspeaker as well as privately with a headset or a handset.
In the open-listening operating mode, with both the loudspeaker and an external microphone turned on, acoustic feedback is suppressed by adjustment of a front panel sidetone (balance) control. This control cancels the originating microphone signal in the local loudspeaker. Most any type of microphone can be used, for example a handheld push-to-talk microphone or a headset/handset microphone.
In the private operating mode, almost any headset or handset can be used while the loudspeaker is turned off. This method can be extended by using the loudspeaker for monitoring and the headset or handset for conversation.
Practical operating features include 2-channel selection, latching and momentary-action microphone on/off switches, a speaker on/off switch, a sidetone control, and a headphone/loudspeaker volume control.
Screw terminals mounted on the circuit card are provided for user station interconnection to line. A 2-pair shielded cable such as Belden 8723 or equivalent is recommended since it allows each channel to be carried over a shielded pair, thus reducing the possibility of crosstalk between channels.