Revision B • 7/00
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5 Maintenance & Alignment
TELCO INPUT/OUTPUT MODULE
There is one trimpot adjustment on the Telco
module. The trimpot (RV1) is used to set the in-
put level from the hybrid (-10 to +4 dBu) so that
a n4 dBu output is available at the left To
Tape output connector. To set RV1:
1.
Connect a 1 kHz signal to the From Hybrid
connector using the hybrid’s output level.
2.
Monitor the To Tape Left output.
3.
Adjust RV1 for a +4 dBu output.
OUTPUT MODULE
To access the Output module analog level
trimpots, the module must be placed on an ex-
tender card (PR&E # 99-1014). There are seven
trimpots to adjust the analog signal output levels.
There are no adjustments for the digital outputs
or for the bargraph meters.
Before adjusting the program output levels, the
meter selector DIP switch (DS1, switch 2) must
be set to VU and one Input module must first be
set up as a “standard” so that a known input level
is feeding the Output module amplifiers. To set up
an Input module as a standard:
1.
Connect an 4 dBu, 1 kHz balanced
signal to the left and right inputs on the A
Input.
2.
Set the fader to the nominal -12 dB mark.
Select A Input and assign the module to all
three program buses.
3.
Adjust Trim L and Trim R for 0VU dBu in-
dications on the Program 1 left and right
meters.
Do not change the standard module settings
until after the Output module adjustments are
completed. To set the Output module:
1.
Place the Output module on an extender
card.
2.
Turn off all other Input and Telco modules,
leaving only the “standard” Input module On,
feeding all three program buses with the
1 kHz input at nominal level.
3.
Plug an AC Voltmeter into the analog Pgm-
1 left output. Adjust RV3 for +4 dBu. Move
the AC Voltmeter to the analog Pgm-1 right
output. Adjust RV2 for +4 dBu.
4.
Move the AC Voltmeter to the analog Pgm-2
left output. Adjust RV4 for +4 dBu. Move
the AC Voltmeter to the analog Pgm-2 right
output. Adjust RV5 for +4 dBu.
5.
Move the AC Voltmeter to the analog Pgm-3
left output. Adjust RV6 for +4 dBu. Move
the AC Voltmeter to the analog Pgm-3 right
output. Adjust RV7 for +4 dBu.
6.
Select Pgm-1 for the Monaural Output.
Move the AC Voltmeter to pins 1, 2 and 3 of
the Mono output connector. Adjust RV1 for
+4 dBu.
MONITOR MODULE
The only trimpot (RV1) on the Monitor 1 cir-
cuit board sets the built-in Talkback microphone’s
output level. It is adjusted through the front panel.
There are no adjustments on the Monitor 2 board.
CLOCK/TIMER ASSEMBLY
There is one frequency adjustment (C2) on the
board. Allow at least one hour of powered opera-
tion to stabilize the internal oscillator before ad-
justing the frequency. To adjust the master clock
oscillator, monitor the CLK test point using a x10
probe with a high-frequency counter. Adjust C2
for exactly 3.276800 MHz.
Clock/Timer Troubleshooting
Red LED flashing below clock:
Clock set for Slave mode
without ESE time code on J3. Change switch
S1, #1 from Off to On if ESE is not being
used. Test ESE system if time code is feed-
ing J3.
