TM 11-6625-648-12
References
Item to be inspected
Procedure
Sequence No.
While making operating checks (items 7, 8, and 9), ob-
6 . . . . . . . . . Controls and indicators . . . . . . . . . .
serve that mechanical action of each knob, dial, and
switch is smooth and free of external or internal bind-
ing, and no excessive looseness is apparent. Also,
check TEST METER for sticking or bent pointer.
7 . . . . . . . . . BATTERY POWER switch . . . . . .
Pull to on position. Momentarily operate METER
SELECT switch to BATTERY. Note that TEST
METER indicates full scale or in green zone. Close
assembly case cover fully and open again. Momen-
tarily operate METER SELECT switch to BATTERY
and note that TEST METER does not indicate.
a. Operate BUZZER switch to ON. Operate ORDER-
8 . . . . . . . . . Call indicator lamp and buzzer. . . .
WIRE switch to SIG. Note that buzzer sounds
and CALL indicator lamp becomes illuminated.
b. Hold ORDERWIRE switch at SIG and operate
BUZZER switch to OFF. Note that buzzer stops
sounding while CALL indicator lamp remains &
luminated.
9 . . . . . . . . . Headset H-91A/U . . . . . . . . . . . . . .
Put on H-91A/U after connecting it to HEADSET con-
nector. Operate ORDERWIRE switch to SIG. Note
1,600-cps tone and buzzer sound. Operate ORDER-
WIRE switch to TALK. Talk into microphone. You
should hear your own voice. Note that CALL indica-
tor lamp does not flicker while talking.
4-3. Organizational Monthly Preventive Maintenance Checks and Service Chart
Procedure
Sequence No.
Item to be inspected
References
Inspect handles, latches, and hinges for looseness. Replace or tighten as
1 . . . . . . . . Handles and latches . . . . . . . . . . . . .
necessary.
2 . . . . . . . . Metal surfaces . . . . . . . . . . . . . . . . .
Inspect exposed metal surfaces for rust and corrosion. Clean and touchup
paint as required.
Inspect gasket that provides seal between case and cover. Check seat for
3 . . . . . . . . Gasket . . . . . . . . . . . . . . . . . . . . . . . .
damage.
Binding posts . . . . . . . . . . . . . . . . . .
Observe that all binding posts are operable by inserting a cable into each.
4........
Inspect probes for chafed, cracked, or frayed insulation.
Probes . . . . . . . . . . . . . . . . . . . . . . . .
5 ........
Observe that orifice is not blocked.
Breather valve . . . . . . . . . . . . . . . . .
6
Loosen 10 captive screws on front panel and remove chassis. Open bat-
7. . . . . . . . . .
Battery compartment . . . . . . . . . . . .
tery compartment and inspect interior for evidence of water, leakage,
condensation, and corrosion. Check door fasteners for correct opera-
tion.
Accessory box . . . . . . . . . . . . . . . . .
8 .......
Open accessory box door, remove contents, and examine interior. Check
two door fasteners.
Front-panel gasket . . . . . . . . . . . . . .
Inspect gasket that seals front panel. Look for aging or damage. Gasket
9 .......
must be clean, flexible, and in good condition.
Preservation. . . . . . . . . . . . . . . . . . .
Check all surfaces for evidence of fungus. Remove rust and corrosion,
10 . . . . . . .
and paint bare spots.
See mat AN/PTM-7 is clean inside and out. Clean as necessary.
Cleanliness . . . . . . . . . . . . . . . . . . . .
11 . . . . . . .
Spare lamp . . . . . . . . . . . . . . . . . . . .
12 . . . . . . .
Check spare incandescent lamp (GE-328) in accessory box cover. Apply
volts dc to lamp to determine if it will illuminate.
Tightness . . . . . . . . . . . . . . . . . . . . .
Tighten any external securing screws that are loose.
13. .,....
See that there are four laminated instruction cards, and that they are
14 . . . . . . .
Simplified instructions. . . . . . . .
complete, serviceable, and current. Check fastener holding cards
together.
4-2
Change 4