C.2.3.3 rf converter module, C.2.3.4 synthesizer sum loop module, C.2.3.5 synthesizer fine step module – Comtech EF Data DT-4500-A Series User Manual
Page 159: C.2.3.6 reference oscillator module, C.2.3.7 temperature fault
DT-4500-A Series Downconverters
Revision 1
Appendix C
MN-DT4500A
C–3
check for other module faults, and check all connections. If the fault still exists, remove the
converter and return it to Comtech EF Data for repair.
VCC (+5 VDC): A fault ("FT") indicates a voltage level exceeding ± 10% of the power supply
voltage. The 5 VDC is developed in the modules. Check the output of the 15 VDC Power Supply
Module, check for other module faults, and check all connections. If the fault still exists, remove
the converter and return it to Comtech EF Data for repair.
C.2.3.3 RF Converter Module
IFLO Lock Detect: A fault (“FT”) indicates that the IFLO is not locked. Check all connections to the
converter module to make sure they are secure. If the fault still exists, remove the Converter
Module and return it to Comtech EF Data for repair.
C.2.3.4 Synthesizer Sum Loop Module
Sum Loop Detect: A fault (“FT”) indicates that the sum loop is not locked. Check all connections
to the converter module to make sure they are secure. If the fault still exists, remove the Sum
Loop Module and return it to Comtech EF Data for repair.
C.2.3.5 Synthesizer Fine Step Module
Coarse Loop Detect: A fault (“FT”) indicates that the coarse loop is not locked. Check all
connections to the converter module to make sure they are secure. If the fault still exists, remove
the Fine Step Module and return it to Comtech EF Data for repair.
Fine Loop Detect: A fault (“FT”) indicates that the fine loop is not locked. Check all connections to
the converter module to make sure they are secure. If the fault still exists, remove the Fine Step
Module and return it to Comtech EF Data for repair.
C.2.3.6 Reference Oscillator Module
Reference Lock Detect: A fault ("FT") indicates that the reference oscillator detected an external
reference, but could not lock to it. Disconnect the external reference. If the fault still exists,
remove the Reference Module and return it to Comtech EF Data for repair.
C.2.3.7 Temperature Fault
Converter Over Temperature Fault: A fault ("FT") indicates that the converter is over
temperature. Turn the prime power switch off and return the converter to Comtech EF Data for
repair.