GAI-Tronics Electro Sound Electro-Sound Communication System - Manual (Page 6)

Pub. 42004-072D
Electro-Sound Communications System Page: 6 of 9
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Two-Wire System with Optional Monitor Speaker
A basic Electro-Sound system provides communications between 2 to 15 handsets or headsets tied to one
pair of wires. Such a system can be interconnected as shown in Figure 7. This diagram also shows an
optional monitor or call-in speaker system for the dispatcher or supervisor.
The system provides a monitor and/or call-in speaker that may be mounted in the vicinity of the dispatcher
or supervisor station. The input to the speaker amplifier is muted when the handset of that station is
removed from its hook. If muting is not desired, omit the red wire in the three-conductor cable attached to
that station, and install a wire link between terminals 7 and 11 in the power source enclosure.
Only one permanent station and one jack station are shown for drawing simplicity. There is no limit to the
number of stations that can be installed in a system. However, the power source is current-limited to 15
operating stations.
Suggested wire colors are shown to aid in connection identification. The stations will not function if
polarity is reversed. Cables to and between stations must be kept separate from the power source.
Figure 7. Typical 2-wire System with Monitor Speaker