21
CM-CU21 Rear Panel Controls & Connections 2
Test Tone Manual Mode
With the test tone in manual mode, all On Air and Talkback buttons will
flash amber. The test tone can be routed to the Comm and Talkback
outputs by pressing the corresponding On Air or Talkback buttons. The On
Air buttons will illuminate red when pressed and the Talkback buttons will
illuminate green. When the button is released, the tone on that output will
be muted.
Test Tone Auto Mode
With the test tone in auto mode, each of the Comm and Talkback outputs
are automatically identified by a unique number of short tone bursts,
lasting 0.25 seconds each, which are repeated every 3 seconds. Each
button flashes when tone is being routed to the corresponding output. The
number of pulses on each output is shown below:
Comm 1
1 pulse
Comm 2
2 pulses
Comm 3
3 pulses
Talkback A
4 pulses
Talkback B
5 pulses
The 4 return audio inputs function normally when the test tone is enabled.
This could be useful in allowing the user to receive instructions on which
channel to output tone to when using the test tone in manual mode. When
the test tone is disabled, normal operating mode is resumed and the On
Air and Talkback buttons will be returned to the state they were in prior to
entering test tone mode.
Talkback Controls
The TALKBACK GANG switch links the operation of each of the
commentator’s TALKBACK A and B buttons. When this switch is on, pressing
one of the TALKBACK buttons automatically activates the commentators’
other TALKBACK button. Up to an additional 12dB of gain is available on
all talkback outputs, if required. This is applied prior to the limiter and is
adjusted using the rear panel GAIN potentiometer.
Return Audio Inputs
The four transformer balanced return audio inputs, Prog, A, B and C are via
3 pin female XLR-3 connectors with the following connections:
Pin 1: Ground
Pin 2: Phase
Pin 3: Non-phase
Audio Outputs
The three electronically balanced commentator outputs Comm1-3, and the
transformer balanced talkback A and B and mix outputs are all via 3 pin
male XLR-3 connectors with the following connections:
Pin 1: Ground
Pin 2: Phase
Pin 3: Non-phase
DC Supply Input
The commentator unit can be powered from an external, regulated 12V or
24V DC power source. The DC input is via a 4 pin male XLR-4 connector with
the following connections:
Pin 1: 0V
Pin 2: No connection
Pin 3: No connection
Pin 4: +VE (12-24 Volt DC)
When powering the Commentator Unit via the DC supply input, it is
important to ensure the unit is suitably earthed. An earth connection point
is provided on the rear panel in the form of a M4 stud and screw and this
should be connected directly to a technical earth.
