Clear-Com PS-704 - Manual (Page 7)

P S - 7 0 4 F O U R - C H A N N E L P O W E R S U P P L Y
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OPERATION
INTRODUCTION
Congratulations on choosing this Clear-Com product. Clear-Com was
established in 1968 and remains the market leader in providing intercoms for
entertainment, educational, broadcast and industrial applications. The
ruggedness and high build-quality of Clear-Com products defines the industry
standard. In fact, many of our original beltpacks and main stations are still in
daily use around the world.
The PS-704 power supply is a powerful, yet user-friendly unit that can serve
as the heart of a Clear-Com system. We recommend that you read through this
manual completely to better understand the function of the PS-704 and how to
optimize your system setup. Please pay particular attention to the section on
system wiring, as improper wiring detracts from the performance of the
system or causes system failure. If you encounter a situation or have a
question that this manual does not address, contact your dealer or call
Clear-Com directly at the factory. Our applications support and service people
are standing by to assist you. (Refer to Chapter 6: “Warranty” for contact
information.) Thank you for selecting Clear-Com for your communications
needs.
THE CLEAR-COM CONCEPT
Clear-Com is a closed-circuit intercom system that consistently provides
high-clarity communication in both high-noise and low-noise environments.
A basic system consists of a single- or multi-channel power supply or main
station connected to various single- or multi-channel remote stations, such as
beltpacks and loudspeaker stations.
Clear-Com is a distributed amplifier system; each main and remote station
houses its own mic preamplifier, headset or speaker power amplifier, and
signaling circuitry. Stations bridge the intercom line at a very high impedance
and place a minimum load on the line. The audio level always remains
constant, and does not fluctuate as stations leave and join the system.
Low-impedance mic input lines and specially-designed circuitry make
Clear-Com channels virtually immune to RFI and dimmer noise.
Clear-Com stations are interconnected with two-conductor, shielded
microphone cable (or individually shielded multi-pair cable as required).
Portable stations are connected with two conductor cables with 3-pin XLR
connectors. One wire, connected to pin #2, carries the DC power from a main
station or power supply to all remote stations. The other wire, connected to
pin #3, carries the two-way (duplex) audio information. The shield, connected
to pin #1, acts as a common ground. One termination per channel is needed