TM 11-6625-2629-14&P
CAUTION
k n o b s ; us a soft clean lint-free cloth. If
DO NOT press on the meter face (glass)
necssary, dampen the cloth with water mild soap
when cleaning; the meter may become
may b. used for more effective cleaning. Wipe dry
damaged.
with a clean lint-free cloth.
d. Clean the front panel, meters, l nd control
Table 4-3. Organization Troubleshooting
Probable cause
Malfunction
Corrective action
Power indicator does not light,
a. Defective fuse.
a. Replace fuse (pus 4-10),
b. Defective lamp.
LIMITING meter does not
Defective vacuum tube V2.
Replace vacuum tube V2.
indicate in black l raa.
CARRIER-SHIFT meter does not
Defective vacuum tube V2, V7, V8
Replace defective vacuum tube.
indicate zero,
or V9,
DEVIATION meter does not
Defective vacuum V10, V11, W12,
Replace defective vacuum tube.
deflect.
V13 or V14.
4-12. Functional Testing
b. Removal and Replacement of Tubes.
CAUTION
The modulation meter should be checked for
DO NOT rock or rotate a tube when
correct operation after any maintenance is per.
removing it from a socket. pull it straight
formed. Appropriate checks are contained in
Out with a tube puller.
Tubes with shields. To remove the tube
these checks insures that the modulation meter is
shield, press. it down and turn it counterclockwise
ready for operation. Should the modulation mater
t o unlock, Remove the tube shield. After
replacing the tube, replace the tube shield by
corrective action for a particular abnormal in.
pressing the tube shield down and turning it
dication. If the indicated corrective action does
cbckwise until it locks in place.
not correct the abnormality, the modulation
(2) Tubes with retainers. To remove the tube
meter must be sent for higher level maintenance.
retainer, compress the spring portion of the
4-13. Vacuum Tube Replacement
retainer that fits on the post and lift up. After
replacing the tube; place the retainer over the
u. If tube failure is suspected (V2 through V18),
post, compress the spring, and fit the retainer
use the applicable procedure ((1) or (2) below) to
over the tube by lowering it on the post. When the
remove and replace the tubes. Replacement of V1
retainer is in its proper position, release the
should be made by the general support main-
spring.
tenance level.
4-4
