User's Manual

Manual 7-9386-1 Page 23TX RX Systems Inc. 09/30/04
61-68-50 UserMan page 23 of 25
Power Supply Replacement
The SB II power supply assembly is field replace-
able. Follow the steps listed below in sequential
order. The required tools are a #1 Phillips screw-
driver.
1) Turn off AC power at the junction box.
2) Disconnect the 3 conductor cable that brings
AC power to the supply from the junction box.
3) Disconnect the red and black leads from the
power supply that connect to the card cage.
4) Remove the Phillips screws that hold the power
supply mount bracket to the back plate and
remove the assembly from the cabinet.
5) Reverse steps 4 through 2 to install the replace-
ment power supply.
Duplexer / Filter Replacement
The component assemblies of the duplexer are
field replaceable. Follow the steps listed below in
sequential order. The required tools are a #1 Phil-
lips screwdriver with an extended shaft to reach
down far enough into the unit to loosen mounting
screws.
Note:
Power to the SB II cabinet must
be turned OFF during the assembly
replacement process.
1) All RF cables attached to the assembly must be
removed.
2) Remove the Phillips screws that hold the
assembly mount brackets to the back plate and
remove the assembly from the cabinet.
3) Reverse steps 2 and 1 to install the replace-
ment assembly. When replacing the RF cables
do not overtighten the SMA connectors. They
should be tightened just slightly more than hand
tight or to the specification of 7 in/lbs.
Card Cage Replacement
To replace the card cage follow the steps listed
below in sequential order. The required tools are a
#1 Phillips screwdriver with an extended shaft to
reach down far enough into the unit to loosen the
mounting screws.
Note:
Power to the SB II cabinet must
be turned OFF during the card cage
replacement process.
1) Disconnect the display/user interface assembly.
2) Disconnect 4 cables at the backplane of the
card cage which are assessable with the dis-
play/user interface board out of the way.
3) Remove the row of Phillips screws which hold
the card cage to the back plate. There is a row
of screws at the top and bottom of the cage.
4) To install a replacement cage perform steps 3
through 1 in reverse order.
RECOMMENDED SPARES
It is recommended that one spare of each of the
following assemblies be kept on hand for emer-
gency repair purposes; Power Supply 8-20667,
Uplink/Downlink Power Amplifier either 3-20806, 3-
20807, 3-20303, or 3-20628 (depending on the
specific model of UHF SB II), Mid Level Amplifier
Card 3-19576, Low Level Amplifier Card 3-19935,
Low Gain Amplifier Card 3-20294, Attenuator Card
3-20208, Power Distribution Card 3-19833, Con-
troller Card 3-19832, and the Display/User Inter-
face Assembly 3-19831.
NOTE
NOTE