Troubleshooting guide

ARTEX AIRCRAFT SUPPLIES, INC. 570-1600
3. To pass the test, you must hear the 3 sweeps on the radio AND see the front panel light
immediately begin to flash continuously. During the ON to ARM transition, the
microprocessor in the ELT checks the “G-switch” (automatic activation switch) latching
circuit, pins 5 & 12 on the D-sub connector at the ELT; the 406 MHz transmitter for
proper RF output and a battery check. If the ELT is working properly, the sequence
following entry to the “ARMED” (OFF) condition will result in the panel LED staying
illuminated for approximately 1 second, then extinguishing.
4. Always perform the tests within the first 5 minutes after the hour. Notify any nearby
control tower of your intensions, in accordance with AC 43.13. If outside of the US,
always follow all local or national regulations for testing of ELTs.
Caution
Do not allow test duration to exceed 5 seconds.
A false alarm may be generated.
Any time the ELT is activated it is transmitting a 121.5 MHz distress
signal. If the unit operates for approximately 50 seconds, a “live” 406
MHz distress signal is transmitted and is considered valid by the satellite
system. Any time that the ELT is cycled from “ARM” to “ON” and then
back to “ARM”, a 406 MHz signal is transmitted, however it is specially
coded as a “Self-Test” signal that is ignored by the COSPAS-SARSAT
satellites.
121.5 MHz Test
Tune a receiver (usually the aircraft radio) to 121.5 MHz. Turn the ELT aircraft panel switch
“ON” for about 1 second, then back to the “ARM” position. The receiver should voice about 3
audio sweeps.
At turn-off (back to ‘ARM’ state) the panel LED should present 1 pulse. If more are displayed,
determine the problem from the list below.
Codes displayed with the associated conditions are as follows:
1 Flash – Indicates the system is operational and no error conditions were found.
3 Flashes – Bad load detect. Detects open or short condition on the antenna output or cable.
These problems can probably be fixed by the installer.
 Check that the RF cable is connected and in good condition. Perform
continuity check of center conductor and shield. Check for a shorted cable.
 Check for intermittent connection in the RF cable.
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