User's Manual

351804-1 Rev. 100
COM5000-8 TECHNICAL MANUAL
22
3. PA Module Harmonic Filter Fault:
a. Filter relay faults are declared whenever the selected filter relay pair current is above or below
specific hardware set limit.
b. The loss of RF signal through the filter selected also results in a filter fault.
The Transmitter response is to disabled bias from the affected PA Module and reduce system power output
as needed to continue operation.
With a filter fault in a PA module, the System Controller and PA module LED display is as shown below.
PA
Module
FAULT
1.25kW PA
Module LED’s
System Controller FAULT LED’s
PWR
FAULT
TEMP
VSWR
SPLY
AIR
FLOW
FILTER
OFF
ON
OFF
OFF
OFF
OFF
The LED display will only show that a PA module has faulted. The specific fault condition is indicated on the
T-4180 Module Status screen #2.
When selecting a frequency in another filter band and transmitting, the filter fault will be cleared and
transmission at full power restored on that filter and the remaining “good” filters.
4. PA Module Gain Fault:
Gain reduction or complete loss of gain in a 1.25kW PA Module may have a number of causes:
350W AMP protection fuse(s) blown
Driver output transistor failure
Driver pre-amp transistor failure
Loss of 50VDC due to tripped circuit breaker(s) on the Power Supply front panel
Miscellaneous component failures
The Transmitter response is to reduce system power output as needed to continue operation. In some case
the fault condition may cause the bias to be disabled from the affected PA Module.
With a gain related fault in a PA module, the System Controller and PA module LED display is as shown
below.
PA
Module
FAULT
1.25kW PA
Module LED’s
System Controller FAULT LED’s
PWR
FAULT
TEMP
VSWR
SPLY
AIR
FLOW
GAIN
OFF
ON
OFF
OFF
OFF
OFF