TM 1-1510-225-MTF
PROCEDURE
TROUBLESHOOTING
REFERENCE
AVIONICS FLIGHT CHECKS (CONT)
(b) Tuning knobs - Set test fre-
quency. Tune the ADF receiver
to at least three frequencies as
nearly equally spaced as possible
throughout the frequency range
of 200 to 1750 KHZ.
(c) Single or double bearing pointer
source selector switch (EFIS con-
trol panel) - ADF. Both single
and double needle pointers on
both the pilot’s and copilot’s
EHSI should be functionally
checked
(d) Verify accuracy of ADF indica-
tions on pilot’s and copilot’s
EFIS displays over a known
ground reference point appoxi-
mately every 90° throughout
360°.
9. Navigation receivers (VOR/localizer/
glideslope/marker beacon) - Check as
follows:
K11-13,
(a) VOR receivers - Check each
VOR receiver as follows:
(1) NAV 1 AUDIO MONITOR
control - On.
(2) Power, volume, and squelch
test control (VHF navigation
receiver control unit) - On,
adjust volume as required.
(3) Tuning knobs - Set test fre-
quency .
(4) NAV pushbutton selector
switch (EFIS control panel) -
Depress to select VOR 1 or
4-14
