TM 11-5826-225-35
because the output voltage of a supply having
poor regulation, may exceed the maximum
voltage rating of the transistors in the equip
ment being tested. A battery eliminator with
poor ac filtering will create a false indication
of poor filtering in the equipment being tested.
d. The direction tinder set must be turned
off before switching the battery eliminator on
or off, The transient voltages developed by
switching the battery eliminator on and off,
may exceed the "punch-through" rating of
transistor. Also, make certain that either a
600-ohm dummy load or a normal load (such
as a headset) is connected to the direction
finder set audio output before applying power.
Section Il. TROUBLESHOOTING RADIO RECEIVER R1391/ARN83
(2) C o n n e c t the output meter to the
2-4. Test Setup
AUDIO OUT terminals on the test
All bench tests of the receiver, require con-
set.
nections to a 27.5-volt dc power source; Test
Set, Direction Finder Set AN/ARM-93; and
(3) Connect the R.F. OUTPUT X-MULT
various other types of test equipment depend-
output connector of the signal gen-
ing on the particular test. To prepare the re-
erator to the SIGNAL GENERATOR
ceiver for tests, loosen the dust cover retain-
connector on the test set. Use cable
ing screws (fig. 21) and slide the receiver
W2 of the AN/ARM-93.
out of its dust cover. Remove the gear train
(4) Set the switch on the sense antenna
cover and the RF shield. Make the test setup
adapter to 150PF.
as described below.
(5) After making certain the test set DC
a. Confections.
POWER switch is off, connect the
(1) Connect the receiver and test set as
dc power source to the test set. If
shown in figure 2-2, Use the pendant
the aircraft dc source is not avail-
cable, the sense antenna adapter cable,
and cable W3 from the test set.
able, use a battery eliminator capable
Change 4
2-3
Previous Page
