Nautel NG1000, Troubleshooting Manual

Page: 36 / 164

NG1000 Troubleshooting Manual Responding to alarms
Page 1-14 Issue 0.4 2010-10-12
TXA (or TXB) Running
Bias TRANSMITTER A
TRANSMITTER B This alarm occurs when the associated transmitter is
running its biasing routine, during which time it cannot
produce RF power.
TXA (or TXB) SAME
TXF Inhib TRANSMITTER A
TRANSMITTER B This alarm occurs when the associated transmitter is
being inhibited due to receiving a TXF command via
the SAME interface.
TXA (or TXB) SWR
Foldback TRANSMITTER A
TRANSMITTER B This alarm occurs when the transmitter system output
probe measures a reflected power greater than
309 W, at rated power (or VSWR of 3.5:1). The active
transmitter has entered a foldback mode to maintain
the reflected power at 309 W or less. The transmitter
will continue to fold back, as necessary, to maintain
this reflected power, until the system VSWR reaches
5.5:1, at which point the system will shut down and
generate a System High VSWR alarm.
TXA (or TXB) SWR
Shutback TRANSMITTER A
TRANSMITTER B This alarm occurs when the associated transmitter
measures a high VSWR condition on its output,
causing a complete, but temporary loss of RF output
power.
TXA (or TXB) SWR
Shutdown TRANSMITTER A
TRANSMITTER B This alarm occurs when the associated transmitter
shuts down with a complete loss of RF output power
due to repeated cutback, foldback or shutback events.
The system requires a manual reset to recover.
TXA (or TXB) 48V Fail TRANSMITTER A
TRANSMITTER B This alarm occurs when the +48 V power supply’s
output voltage is outside the acceptable range of
43.2 V to 52.8 V. Suspect a possible fault with the +48
V power supply (U2).
TXA (or TXB) +15V
Fail TRANSMITTER A
TRANSMITTER B This alarm occurs when the +15 V power supply
measured on the exciter/control PWB is outside the
acceptable range of 13.5 V to 16.5 V. Suspect a
possible fault with the +15 V supply circuitry on the
exciter/control PWB (A1).
TXA (or TXB) -15V
Fail TRANSMITTER A
TRANSMITTER B This alarm occurs when the -15 V power supply’s
output voltage is outside the acceptable range of
-16.5 V to -13.5 V. Suspect a possible fault with the
-15 V supply circuitry on the exciter/control PWB (A1).
Alarm (with Prefix) Alarm/Status LED Description and Troubleshooting Action