PROCEDURE TROUBLESHOOTING REFERENCE
Transmitter selector switch (audio control panel) - #1 or #2.
Off-volume control - Turn clockwise, set volume as
Frequency selector - Set desired frequency.
Fly aircraft to a point 40 nautical miles away from test
At 40 nautical miles, maintain communication with test
station each 10° while flying a 360° flat turn (not to exceed
5° bank). Communication should be uniformly loud and
clear through these tests.
Repeat procedure for frequencies in low, middle and high
HF radio set - Check as follows.
Transmitter selector switch (audio control panel) - #4.
Mode selector (HF control panel) - Set desired operating
Microphone switch - Press momentarily and wait for
antenna coupler to tune. A 1000 Hz tone will be heard in
the headphones until tuning is complete. Tuning time
should not exceed 30 seconds.