TM 1-1510-223-CL
P-17
2.
VHF naviation receivers (#1 and #2) – Test as
follows:
a. VOR self test/marker beacon test:
(1) Tuning knob (NAV control unit) – Se-
lect a VOR frequency.
(2) VOR/localizer push – button selector
switch (display controller) – Select
VOR1 or VOR2.
(3) Single needle bearing pointer source
selector switch (display controller) –
VOR 1.
(4) Double needle bearing pointer source
selector switch (display controller) –
VOR 2.
(5) Course knob (EHSI) – Rotate until
pointer indicates 0 degrees.
(6) TEST button (NAV control unit) – De-
press. Normal test will show dashes
in the active window and 00 in the pre-
set window. A fault will show DIAG in
active display and a two digit fault
code in the preset display.
(7) NAV flag on the EHSU – Will come
into view. After two seconds, the flag
will go out of view, the EHSI course
deviation bar will center, and a TO in-
dication will appear. The bearing
pointers will indicate a 0 magnetic
bearing. The VIR - 32 will return to
normal after 15 seconds.
(8) EHSI – Check for three marker bea-
con indications (I, O, M illuminates)
and listen for a 30 Hz tone on B audio
channel of intercom box.
