User's Manual

The power amplifier is comprised of six internal modules:
• Core Board
• Converter Board
• Driver Amplifier Board
• Final Amplifier Board
• Distribution Board
• Output Circuitry
Power Amplifier Input/Output Connections
There are three electrical connection assemblies on the power amplifier:
• RF output (front QN "quick-N" connector) on the front of the power amplifier module
Note: This is cabled to the N-type female bulkhead connection at the rear of the base radio housing.
• DC power supply/control signal (backplane connection)
• RF input/feedback (backplane connection).
Figure 11: Power Amplifier (Backplane Connections)
Function of the Fan Module
The fan module provides intermittent forced-air cooling for the power amplifier and transceiver modules. The fan
module houses two 119 mm axial fans which deliver a total of approximately 160 cubic feet per minute of airflow.
Nominal fan speed is 4100 revolutions per minute. A thermostat behind the fan module controls each fan. If the fan
speed for either fan falls below 30% of the rated speed, a built-in speed sensor on each fan turns on the red Fan Alarm
LED.
If the fan module is used for the Power Efficiency Package, the following must be configured in the Configuration/
Service Software (CSS) to take full advantage of the Power Efficiency Package:
• Optional fan holdover time (length of time the fan stays ON after transmission).
• Disabling one of the fans within the fan module. See Replacing the Fan Assembly on page 226 for instructions on
how to disable one of the fans.
• Configuring the base radios Tx Power Out in the CSS should be limited to 50 W.
The fan module connects to the backplane through a 4-pin port on the front of the chassis.
GTR 8000 Base Radio Theory of Operation | 67
6871024P71-A | November 2013 | Send Feedback
Applicant: Motorola Solutions
Equipment Type: ABZ89FC5810B / 109AB-5810B
Exhibit D (Permissive Change)