b. When the AN/PTM-7 has been exposed
4245/G from the TS-1323/PTM-7.
to the cold and is brought into a warm room,
Reconnect the TD-206/G to the CX-
leave the cover closed, Moisture will condense
4245/G, or connect the two CX-4245/
o n all cold surfaces until the AN/PTM-7
G's as appropriate.
r e a c h e s room temperature. When the AN/
Disconnect the H-91A/U from the
P T M - 7 reaches room temperature, dry it
TS-1323/PTM-7 HEADSET connec-
c. Special low-temperature batteries should
Return the H-91A/U and probes to
be used for operation at subzero temperatures.
the accessory box in the TS-1323/
Battery voltage will drop when the batteries
P T M - 7 cover.
are cold. This will result in weaker signals on
Close the cover on the carrying case
the order wire, and in some amount of inac-
and fasten the latches.
curacy when tests are made. The BATTERY
voltage will indicate low at extremely cold
b. PCM Probe.
temperatures. Do not dispose of good bat-
(1) D e p r e s s t h e B A T T E R Y P O W E R
teries by mistake.
(2) Disconnect the pcm probe from the
3-10. Operation in Tropical Climates
When operated in tropical climates, the AN/
(3) Return the probe to the accessory
PTM-7 may be stored in tents, huts, or, when
box in the cover.
necessary, in underground dugouts. When
(4) Close the cover on the carrying case
equipment is stored below ground level, or
and fasten the latches.
when it is set up in swampy areas, moisture
becomes more of a problem. High humidity
3-9. Operation in Arctic Climates
Subzero temperatures and climatic condi-
whenever its temperature becomes lower than
tions associated with cold weather affect the
that of the ambient air. To minimize this con-
efficient operation of the equipment. Instruc-
dition, keep the AN/PTM-7 case cover fastened
tions and precautions for operation under
when the equipment is not in use. Cover the
such adverse conditions follow:
A N / P T M - 7 with a tarpaulin or any other
a. The shock-resistant characteristics of
materials change at very low temperatures.
(1) Metals shrink and become brittle.
3-11. Operation in Desert Climates
Handle the equipment with reason-
The main problem in operating in desert
areas in the large quantities of sand and dust
(2) Canvas loses its pliability. Handle the
which enter the equipment. Though the AN/
carrying case strap very carefully to
PTM-7 is enclosed in a case, be careful to place
the AN/PTM-7 in a location which is as dust-
(3) Wiring becomes brittle. Handle the
free as possible. Keep the case cover fastened
when the AN/PTM-7 is not in use.