VX150 TO VX2 TROUBLESHOOTING MANUAL
RESPONDING TO ALARMS
PAGE 3.1.12
VERSION 0.1 2020-12-01
No External 10 MHz
This alarm occurs if frequency locking to an external 10 MHz source is enabled and no
external 10 MHz is detected. The exciter will automatically switch over to the internal
10 MHz reference, and will continue to run. Check the 10 MHz input. If there are no
problems with the 10 MHz signal and connection,
suspect the Exciter/Control PWB (A1)
.
No LAN Connection
This alarm occurs if the transmitter is not detecting communication over the LAN connection.
T
his alarm is typically only visible in the Events Log, since it will not be transmitted when
communication is interrupted
.
No One Pulse per Second
This alarm occurs if the pilot phase locking to 1 PPS is enabled and the 1 PPS signal is not
present. Check the 1 PPS input. If there are no problems with the 1 PPS signal and
connection, suspect t
he Exciter/Control PWB (A1)
.The transmitter takes no action on this
alarm
Overall Summary
Not displayed in AUI or UI status. Configurable as a remote output.This alarms occurs if there
are any alarms present. Check for associated alarms, and follow the associated
troubleshooting procedure, if present.
PA Fail Foldback
This alarm occurs if the control system determines that the calculated dissipation in any FET
on a PA is above the high dissipation threshold (?? W), or the forward power being asked for
out of an individual PA [calculated as (output power - combiner losses) / number of active
PAs in the system] is above the PA output high threshold (400 W)(850 W for VS2.5 or 900 W
for VS3). The forward power of the transmitter will be limited to a level such that neither of
these thresholds are exceeded. Check for associated alarms. Typically, the assertion of this
alarm is the result of a PA failure or removal, or a high SWR condition. If no other alarms are
being indicated, contact Nautel for further support
PA Fail/PA1 Fail
This alarm occurs if the dc input current for the PA (A7), also PA1 for VX1.5/VX2 transmitters)
has fallen below a predetermined threshold (typically less than 50% of the average PA
current of the operational PAs, or below 500 mA, whichever is lower). This may be caused by
a cabling fault on the PA, loss of PA voltage or bias, or a defective FET.
The transmitter's
output power will be reduced (see Table 1.3 on page 1-31) and this condition could cause Per
PA Foldback and Reject Foldback alarm
s. Perform the “PA resistance checks” on page 1-37.
If there is no problem found with the PA, or the alarm still persists after replacing the PA,
s
uspect the PS Distribution PWB (A2)
.
PA2 Fail
For VX1.5/VX2 transmitters only. This alarm occurs if the dc input current for PA2 (A8) has
fallen below a predetermined threshold (typically less than 50% of the average PA current of
the operational PAs, or below 500 mA, whichever is lower). This may be caused by a cabling
fault on the PA, loss of PA voltage or bias, or a defective FET.
The transmitter's output power
will be reduced (see Table 1.3 on page 1-31) and this condition could cause Per PA Foldback
and Reject Foldback alarm
s. Perform the “PA resistance checks” on page 1-37. If there is no
problem found with the PA, or the alarm still persists after replacing the PA, s
uspect the PS
Distribution PWB (A2)
.
Alarm Name
Description and Troubleshooting Action
Summary of Contents for VX150
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Page 32: ...VX150 TO VX2 TROUBLESHOOTING MANUAL RESPONDING TO ALARMS PAGE 3 1 24 VERSION 0 1 2020 12 01...
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Page 90: ...VERSION 0 1 2020 12 01 MD 2 Figure MD 2 VX1 5 VX2 Transmitter NOT AVAILABLE AT TIME OF PRINT...
Page 91: ...VERSION 0 1 2020 12 01 MD 3 Figure MD 3 NAPI189 Analog Audio PWB...
Page 92: ...VERSION 0 1 2020 12 01 MD 4 Figure MD 4 NAPI187 System Interface PWB...
Page 94: ...VERSION 0 1 2020 12 01 MD 6 Figure MD 6 NAPI188 Power Supply Interface PWB VX1 VX1 5 VX2...
Page 95: ...VERSION 0 1 2020 12 01 MD 7 Figure MD 7 NAPI193 Front Panel User Interface PWB...
Page 96: ...VERSION 0 1 2020 12 01 MD 8 Figure MD 8 NAPA41 Pre Amp IPA PWB...
Page 97: ...VERSION 0 1 2020 12 01 MD 9 Figure MD 9 NAPA40 Power Amplifier PWB...
Page 98: ...VERSION 0 1 2020 12 01 MD 10 Figure MD 10 NAPF16 Low Pass Filter PWB...
Page 99: ...VERSION 0 1 2020 12 01 MD 11 Figure MD 11 NAPP15 Directional Coupler PWB...
Page 100: ...VERSION 0 1 2020 12 01 MD 12 Figure MD 12 NAPH15 2 Way Splitter PWB VX1 5 VX2...
Page 101: ...VERSION 0 1 2020 12 01 MD 13 Figure MD 13 2 Way Combiner PWB Nautel Part PU03A VX1 5 VX2...
Page 103: ...VX150 TO VX2 TROUBLESHOOTING MANUAL LIST OF TERMS PAGE 3 5 2 VERSION 0 1 2020 12 01...
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