Talk Back Connections; Intercom; Internal Adjustments And Input Level Calibration; Mix Bus Output Level Adjust - Radio Systems Millenium-A Analog Console Installation And Operation Manual

Radio Systems Millenium-A Console
4.4

Talk Back Connections

The talk back circuit has two sections, send and receive. The send section will output any signal applied to its input
when the front panel Talk Back Switch is depressed. Return signals are applied to Cue Bus for operator monitoring. A
trim pot on the Output Board is provided to set the external cue input level.
Talk back connections are made via 2 five position terminal strips, titled to Talk Back Output header J36 and Talk Back
Input header J37 on the Output Board.
Under normal applications, the output of the DJ mic is wired to the talk back send input terminal on J37. This is ac-
complished by connecting terminal 4 from patch point connector J8 of the DJ mic channel to terminal 1 of the Talk Back
connector, and shorting terminal 2 (-) of the Talk Back Connector to terminal 3 (G).
Talk Back Output connector J36 also contains terminal 4 labeled "CTL", which is pulled low whenever the front panel talk
back switch is depressed. This is useful for switching external intercom or control circuits. It may also be used to remote
trigger the console front panel Talk Back switch.
Illustration O-4 shows how this configuration would be used to wire two Millenium Consoles for talk back communication
utilizing the DJ mic channel and cue circuit external inputs.
4.4.1

Intercom

The talk back system can also be used to communicate with up to four 2-way speakers in studios or control rooms that
do not have Millenium Consoles. For this application, Radio Systems provides an Intercom card. Consult Illustration
E-6 in the Interface Options and Accessories section of this manual for detailed information.
4.5

Internal Adjustments and Input Level Calibration

The following level trim adjustments are available internal to the console.
1. mix bus output level
2. VU meter "0"
3. peak LED trip point
4. input level for external monitor inputs
5. input level for external cue bus input
6. distortion adjustment for all VCAs
The console was factory calibrated as follows, and will not require re-calibration unless alternate levels are desired.
1. With a +4dBv input and the fader set to the "0" position, the console will provide +4dBm output into a 600
ohm load.In addition, the VU meters will read 100% or 0 VU.
2. The peak LED trip point was calibrated to illuminate the LED when the peak output level reaches +2 dBv.
3. The external monitor inputs were calibrated to provide a lv RMS output with a lv RMS input.
4.5.1

Mix Bus Output Level Adjust

The console was calibrated at the factory for an output level of +4dBv, into 600 ohms, when the VU meters indicate "0".
Perform the following steps on the Six Channel Audio Board to verify or change the calibration.
1. Select a high level input with no DIP component carrier inserted into attenuator headers J3 or J4. In addi-
tion, there should be no jumpers installed onto gain select headers J5 or J6.
2. Disconnect any inputs to the left or right A input.
3. Connect a l kHz, +4dBv, balanced sine signal to both the left and right A inputs.
Select input A, select all mix buses, turn the mixing channel "on", and set the fader to "0".
Perform the following steps on the Output Board.
1. If the console outputs will normally be terminated, place an equivalent termination onto each program and
audition output. In addition, place a termination onto one of the Mono outputs.
2. Connect a high impedance, balanced voltmeter across the + and - Left program output.
3. Adjust the left channel output level trimmer so that the voltmeter indicates the desired output.
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