GAI-Tronics Electro Sound Electro-Sound Communication System - Manual (Page 8)

Pub. 42004-072D
Electro-Sound Communications System Page: 8 of 9
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Coupling Electro-Sound to a GTC Page/Party ® System
A GAI-Tronics two-way amplifier, consisting of a Model 371-202 Plug-In Amplifier and a suitable
372 Series enclosure, is used to interface an Electro-Sound system and a Page/Party
® system. For wiring
convenience, the two-way amplifier should be adjacent to the Electro-Sound power source; however, it also
must be located within 300 feet of the Page/Party
®
system line balance assembly. Also, it will be
convenient for test purposes to have all the above next to a Page/Party ® system wall station.
Figure 9 shows the wiring of a three-wire Electro-Sound system interfaced to a five-party Page/Party ®
system. The handsets or headsets plugged into jack stations are tied to party line five but switch to the
page line whenever the page switch on the handsets or headsets is pushed. The power source contains a
relay that disconnects the coupling when no handset or headset is plugged in and another relay for
switching between page and party lines. The wiring shown in Figure 9 provides ac power to the power
source and interface amplifier from the power source for the Page/Party
® system wall station.
The interface wiring shown in Figure 9 can be used for two-wire Electro-Sound systems and/or situations
requiring coupling to page or party lines (but not both). It is absolutely necessary to place a 33-ohm load
between points four and five or between points six and seven on the power source enclosure terminal blocks
if these points are not connected to a page or party system. The two-way amplifier may oscillate if these
resistors or the Page/Party
®
system line balance assembly is not connected.
Figure 9. Typical Electro-Sound System with GTC Page/Party ® System Interface