TM 11-6625-828-12
(b) Vertical pointer should be centered and steady
tude localizer receiver testing and for the identification of
when omnicourse selector is set on, 30.
radiated test signals. The type of modulation applied to
the carrier is determined by the setting of the
(c) TO-FROM meter should indicate TO.
MODULATION switch. With the switch set to EXT, the
(d) The number of degrees shift in the course
percentage of modulation may be read directly from the
selector required for deflection of the vertical pointer
lower scale of the % M meter. With an audiofrequency
from the last dot on the right to the last dot on the left will
(af) source capable of supplying approximately 1.5 volts
depend on the type of omni equipment being tested.
root mean square (rms) across 20,000 ohms connected
Twenty degrees of shift is considered standard.
to the EXT MOD terminals, approximately 100 percent
(e) See that the audio output resulting from
modulation will be obtained.
identification signals or voice transmission from the SG-
d.
Radiated Signal Testing.
Test Set, Radio
66B/ARM-5 is loud and clear and relatively free from
AN/ARM-5A can be used to perform a flight check of one
extraneous noise.
or more omni tracks and the left-center-right localizer
(5) Set the MODULATION switch to the three AMP
indication with the aircraft within 5 miles of the antenna
LOC positions, in turn, and observe the following
location as follows:
conditions:
(1) Use the RG-58/U coaxial cable to connect the
(a) Switch set to A. The warning flag is down
RF OUTPUT 1 VOLT connector to an unobstructed
out of sight and the vertical pointer moves near the outer
suitable antenna.
edge of the blue sector or 3-dot deflection.
(2) Plug a standard single button carbon
(b) Switch set to B. The warning flag is down
microphone into the MIC jack on the SG-66B/ARM-5
out of sight and the vertical pointer is in the center.
front panel.
(c) Switch set to C. The warning flag is down
(3) Set the IDENTIFIER switch to ON. This will
out of sight and the vertical pointer move near the outer
modulate the SG-66B/ARM-5 test signals by a keyed
edge of the yellow sector or 3-dot deflection.
1,000-cps signal and therefore provide positive
identification of radiated test signals.
3-5. Stopping Procedure
NOTE
a. To place the SG-66B/ARM-5 in standby condition,
Radiated signals should be in
set the POWER-STAND BY switch to STAND BY.
agreement
with
test
signal
b. To shut down the equipment completely, remove
frequencies authorized by Federal
Power Cable Assembly CX-337/U from the POWER
Communications Commission (FCC).
INPUT connector on the front panel.
(4) Set the OMNI TRACK switch to 30 and observe
the following conditions on the omnireceiving equipment:
(a) Warning flag should be down out of sight.
3-4
