If the power-on test or the on line built-in test
equipment detects a fault, either prior to or during the
operation of self test, the system will switch the displayed
mode symbol to an amber LX/F. A special fault message
may be obtained by switching to the CLR/TST mode. In
the CLR/ TST mode an amber LXmn will be displayed,
where mn is a failure code that may be interpreted
according to table 3-13.
Lightning Sensor System Normal Operation.
LSS mode selector switch (radar control
Range switches (radar control panel) - Set
If radar system mode selector switch
is set to OFF, LSS range will revert to
50 nautical miles.
3-33. TRANSPONDER SET (APX-100).
Description. The transponder system receives,
decodes, and responds to interrogations from air traffic
control (ATC) radar to allow aircraft identification, altitude
reporting, position tracking, and emergency tracking. The
system receives a frequency of 1030 MHz and transmits
preset coded reply pulses on a frequency of 1090 MHz at
a minimum peak power of 200 watts. The range of the
system is limited to line-of-sight. The transponder system
consists of a combined receiver/transmitter/control panel
(fig. 3-34) located in the pedestal extension; a pair of
remote switches, one in each control wheel; and two
antennas, located on the underside and top of the
fuselage. The system is protected by the 3-ampere
TRANSPONDER, and 35-ampere AVIONICS MASTER
PWR NO. 1 circuit breakers on the overhead circuit
breaker panel (fig. 2-9).
Transponder Controls, Indicators, and Functions
TEST-GO indicator. Illuminates to indicate
successful completion of built-in-test (BIT).
TEST/MON/NO GO indicator. Illuminates
to indicate system malfunction or interrogation by a
ANT switch. Selects desired antenna for
Table 3-13. Lightning Sensor System Failure Codes
No LX system failure (not displayed)
Power supply out-of-tolerance
Data Processor RAM failure
Data Processor Checksum failure
Data Processor shared RAM failure
I/O Processor RAM failure.
I/O Processor Checksum failure
I/O Processor shared RAM failure
No data from antenna