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LBI-39055
23
❏ Send the LINE A input to the SPKR A output by
typing the following commands:
<F2> 6771 <Enter>
<F2> 7771 <Enter>
<F2> 8731 <Enter>
NOTE
If no headset is connected to the Audio Tower
the initial audio matrix switch settings will
route the LINE A input to the SPKR A
output. Therefore, in this case, execution of
the above commands is not necessary.
❏ Verify the 1 kHz tone is heard in Speaker A.
CTEST's VU meter should indicate yellow.
❏ Adjust the select speaker (Speaker A) volume knob
up and down and verify the volume changes. This
knob is the left-most volume knob on the Volume
Controller Box.
❏ Turn the tone off by typing the following
commands. The first command will turn it off:
<F2> 6770 <Enter>
<F2> 7770 <Enter>
<F2> 8730 <Enter>
Successful completion of this tests verifies basic
operation of the following:
• Line A input circuitry
• Speaker A power amplifier circuitry
• PC and Logic Board's ability to control the cross-
point audio matrix switches on the Audio Matrix
Board
• Volume Controller Box select volume control and
its related cabling
• VU meter circuitry
2. Send LINE B Input Audio to SPEAKER B
❏ Remove the RJ-11 modular plug from the LINE A
jack and connect it to the LINE B balanced input.
The balanced input is the two outside contacts on
the RJ-11 modular jack (yellow and black wires in
a modular cable).
❏ Verify the 1 kHz tone is heard in Speaker B. If
not, send the LINE B input to the SPKR B output
by typing the following command:
<F2>
6641
<Enter>
❏ Adjust the unselect speaker (Speaker B) volume
knob up and down and verify the volume changes.
❏ Turn the tone off by typing the following
command:
<F2>
6640
<Enter>
Successful completion of this tests verifies basic
operation of the following:
• Line B input circuitry
• Speaker B power amplifier circuitry
• PC and Logic Board's ability to control the cross-
point audio matrix switches on the Audio Matrix
Board
• Volume Controller Box unselect volume control
and its related cabling
3. Send Mic Audio To LINE A & LINE B Outputs
❏ If necessary, connect a headset to operator headset
jack box. Verify this jack box is connected to the
OPERATOR HEADSET connector on the Audio
Matrix Board (#1).
❏ Terminate the Audio PA Board's (#1) LINE A
balanced output terminals with a 600-ohm resistor.
The balanced output is the two center-most
contacts on the RJ-11 modular jack (red and green
wires in a modular cable). Connect an oscilloscope
across this load resistor.
❏ Send operator headset mic audio to the LINE A
output by typing the following commands:
<F2>
6331
<Enter>
<F2>
1001
<Enter>
❏ Speak into the headset's mic and verify the audio
signal is present on the LINE A balanced output.
Maximum signal level is approximately 6 Vp-p.
❏ Turn the operator headset mic-to-LINE A audio off
by typing the following command:
<F2>
1000
<Enter>
❏ Verify mic audio is no longer on the LINE A
balanced output.
❏ Move the LINE A balanced output 600-ohm
termination to the LINE B balanced output.