TM 1-1520-238-MTF
2-19
Change 3
PROCEDURE
TROUBLESHOOTING
REFERENCE
AFTER STARTING APU (CONT)
*19. Avionics On, test, program as
required.
NOTE
Procedures for testing the AN/ARN-149
ADF are in paragraph b.
*a. AN/ARN-89 ADF Radio Test as
follows:
(1) ANT mode operation:
(a) Mode selector ANT.
(b) Frequency Select and
tune.
(c) CW-VOICE-TEST switch
CW. Note detectable BFO
tone in headset.
(d) Tune around selected
station frequency and
check that BFO tone does
vary. Set to null.
(e) CW-VOICE-TEST switch
As desired.
(f) Mode selector As
desired.
(2) COMP mode operation:
(a) Mode selector COMP.
(b) CW-VOICE-TEST switch
CW or VOICE as
appropriate for the received
signal.
(c) AUDIO control Verify
range of control. Set as
desired.
B