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REVISION C
BMX SERIES III CONSOLE
96
PACIFIC RESEARCH & ENGINEERING
While it is unlikely that a “typical” installation will utilize all of the Talkback/Intercom module logic
facilities, it is important to understand what is available, along with the potential applications.
The TALK TO CONTROL ROOM control input dims the Control Room monitors and enables
Talkback from the Studio to the Control Room when using a line level source connected to the Talk
From Studio Input as the Studio Talkback source. This input will not be used when Talkback is taking
place via a console Microphone Input module, as each microphone input has its own Talkback control
inputs (reference Section 2.8.1).
The TALKBACK control output is a current-sinking open collector, which is active (low) whenever
the Studio is receiving Talkback from the Control Room. This command is intended for connection
to active, self-contained, headphone and monitor systems, and is used to switch the Talkback signal into
the headphone and monitor circuits. Such headphone and/or monitor systems are usually provided to
the host and co-host positions.
The TALKBACK WITH MUTE control output is a current-sinking open collector, which is active
(low) whenever the Studio is receiving Talkback from the Control Room. This output differs from the
TALKBACK output (pin 3) in that it is disabled whenever the Studio is muted.
NOTE: The TALKBACK WITH MUTE output will function identically to the TALKBACK output
by cutting the jumpers between points E1 and E2 (for Studio-1) and E3 and E4 (for Studio-2) on the
Talkback/Intercom Module PC assembly. Also, PR&E #99-371-1 is equipped with a front panel TALK
OVER MUTE button which, when depressed, performs the same function.
The MUTE control output is a current-sinking open collector, which is active (low) whenever a
Microphone Input Module assigned to the Studio is turned ON. This command is provided for interface
to intercoms, telephones and/or other external equipment which may need to be muted whenever a
Studio microphone is “live”.
The DIM control output is a current-sinking open collector, which is active (low) whenever Talkback
is occurring from the Studio to another location via a console Microphone Input Module. This
command is provided for similar applications as the MUTE Command.
The STUDIO WARNING tally is a 12 volt DC, 150 mA maximum, source output for connection to
a magnetic or solid-state relay unit for driving the Studio entry warning light(s).
INTERNAL OPTIONS
The Talkback/Intercom module is equipped with a two-station internal option DIP switch (S3) which
determines how the Studio-1 and Studio-2 dim functions affect Talkback communication.
NOTE: Since the Studio only dims when Talkback is occurring via a console Microphone Input
module, this switch will have no effect when the Talk From Studio Input is being used.
Closing S3-1 causes the Studio-1 dim function to block incoming Talkback signals to Studio-1. Closing