User's Manual

A-5
A.1.1 External Fan Assembly
See Figure A-3. The external fan assembly PN 3EM11901ABAA is required for cooling
the CommPak indoor unit equipped with high-power amplifiers, for specific frequency
bands, as follows:
The external fan assembly is wired to the CommPak indoor shelf internal fan assem-
bly PN 3EM14510AAAA via cable. The internal fan assembly passes +12 Vdc operat-
ing power to the external fan assembly, and the internal fan assembly passes 12C and
alarms from the external fan assembly.
The external fan assembly mounts to the rack rails directly below the heatsink on the
CommPak indoor shelf with four screws. The external fan assembly cools by blowing
air between the vanes on the heatsink. Fan revolutions are monitored and an alarm
occurs if any one or more fans loses rpm.
Figure A-3 External Fan Assembly
A.2 INTERCONNECT
This part of the section gives the location and describes strapping, power connections,
signal connections, status and alarm connections and service channel connections for
the CommPak indoor shelf.
A.2.1 Power Cable Assembly
See Figure A-4 for power cable assembly installation procedures. The MDR-8000 is
internally wired to accept 20.5 to 60 V dc input power with positive or negative ground.
To protect maintenance personnel from lightning strikes, the ground system must be
integrated by bonding station ground and dc battery return together. The dc power
connectors J1 and J2 are located on the rear of the back panel. Install power cables as
shown.
Radio Output Power
MDR-8505u +30 dBm
MDR-8506 +31 and +33 dBm
MDR-8510/8511 +29 dBm
MDR-1025
06/12/04