GAI-Tronics Electro Sound Electro-Sound Communication System - Manual (Page 7)

Pub. 42004-072D
Electro-Sound Communications System Page: 7 of 9
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Three-Wire System with Paging Speakers
With a third conductor in the cable between stations and connected to the power source, pressing the push-
switch on any handset or headset in the system will connect the signal line to a paging amplifier system.
Figure 8 shows a simplified system using a GAI-Tronics speaker amplifier. One or two additional
amplifiers may be connected if needed.
Paging speakers located near jack stations must be positioned to minimize the possibility of
acoustic-feedback when page calls are made from the handset or headset plugged into that station. Paging
speakers in close proximity to permanent stations may be wired to the hook-switch of the station. This
mutes the speaker when the handset is off the hook and prevents acoustic feedback.
Only one jack station and two permanent stations are shown in Figure 8 for drawing simplicity. 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 the polarity is reversed. Cables to and between stations
must be kept separate from power cables.
Figure 8. Typical Three-wire System with Paging Speakers