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95307-000-01 6/87
RET-041 Instructions
page 5
3) Install NRSC pre-emphasis module on Card #4.
a) Remove Card #4 from its slot.
b) If the serial number of your 9100A/1 is below 700000, install Retrofit Kit RET-033
on Card #4 before continuing instructions are provided with that kit).
c) Unplug the " equalization module " from the socket on Card #4.
Do not remove the module if it is BLUE. See Fig. 2 for location of the module. On
some earlier versions of Card #4, the socket is on a " transition board " assembly.)
d) Insert the BLUE NRSC pre-emphasis module in the socket.
e) Check that jumper A on Card #4 is in the " MONO " position.
f) Return Card #4 to its slot.
) If your serial number is below 700000, attach jumpers to motherboard.
\[Ski this ste if your serial number is 700000 or higher.]
a) \Plug
an extender board into slot #1.
b) Turn the POS
peak
THRESH control fully counterclockwise.
c) Set the MODE switch to OPERATE.
d) Set the AC
power
switch to ON.
e) Measure the voltage between the chassis and pin U and between the chassis and pin
V. If these voltages are about -4.1 VDC and +4.1VDC, respectively, the jumpers are
already in place and you may skip to step 5.
\
f) Set the AC POWER switch to OFF.
\
g) Disconnect OPTIMOD-AM and remove it from the rack.
h) Remove the eight screws that attach the top cover to the rear panel of OPTIMOD-AM.
Also remove the eight screws that attach the bottom cover to the rear paneL
\
i) Set the unit on a padded surface with the rear panel facing you and the bottom cover
down.
\
Leave about 6 inches 15cm) between the rear panel and the edge of the table.
Be sure the AC power cord is unplugged.
j) Remove the three groups of three screws circled in black on the rear panel.
k) Very carefully pull the rear panel about %-inch toward you, and then tilt the top of the
rear panel down until the rear panel is horizontal.
Careful! Watch for snags in the wiring or stress on the ceramic capacitors on the
internal divider wall or RF box. These capacitors are very fragile and are difficult
to replace.
\
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