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RET-041 nstructions
95307-000-01 6/87
i) Disconnect the THD analyzer from TP2.
10) Verify noise performance.
a) Check that jumper A night) on Card #1F1O is in the " 10kHz " position.
b) Connect the audio voltmeter to TP2.
c) Short OPTIMOD-AM ' s input by connecting the
L INPUT +,
and
GROUND
terminals
together.
d) Set the TX EQ DAY/NIGHT switch to DAY.
e) Verify that the level of residual noise, as measured by the audio voltmeter, is less than
-65dBu from 20-20, 000Hz.
dBu = dBm at 600 ohms.
f) Set the TX EQ DAY/NIGHT Switch to NIGHT.
g) Verify that the level of residual noise, as measured by the audio voltmeter, is less than
-65dBu from 20-20, 000Hz.
h) Remove the jumper s) shorting OPTIMOD-AM ' s input.
11) Restore all jumpers to the positions they were in at the beginning of this
alignment and performance verification procedure.
12) Remove the card extender and return Card #1F1O to slot #1.
13) Replace subpanel, close front panel.
The sub anel should always be re laced, since it is an integral art of the chassis RFI
rotection.
a) Disconnect all test instruments from OPTIMOD-AM.
b) Taking care not to stress the flat cables beneath it, tilt the top of the subpanel inward
and to the left to clear the upper chassis lip and the door support at the right
c) Turn the DZUS fasteners ' A-tum clockwise.
The DZUS fasteners turn only y 4 -tum. Don ' t force them, lest they be damaged
in a way that is very time consuming to repair.
d) Set the internal AC POWER switch to ON.
e) Raise the front panel and fasten the three screws that secure it in place.
14) Restore all controls to their settings prior to beginning this alignment and
performance verification procedure.
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