TM 11-5805-424-15/NAVELEX 0967-220-9010/TO 31W2-2G-41
a.
Arctic Climates.
(3) Momentarily depress the TALK REQUEST
pushbutton.
(1)
Keep the equipment warm and dry.
(4) When the TALK REQUEST indicator lights,
(2)
Keep the power on continuously, if possible.
establish communications with the teletypewriter
(3)
When equipment that has been exposed to the
equipment.
cold is brought into a warm room, moisture will
(5) When
communications
are
completed,
gather on it; this may cause a change in
momentarily depress the TALK REQUEST
operating characteristic When the equipment
pushbutton.
reaches room temperature, dry it thoroughly.
(6) When the TALK REQUEST indicator lights,
b. Tropical Climates. In tropical climates, the high
disconnect the teletypewriter equipment from
relative humidity causes condensation on the equipment
the ORDER WIRE jacks, and momentarily
whenever the temperature of the equipment becomes
depress the TALK REQUEST RESET
lower than that of the surrounding air. To minimize this
pushbutton.
condition, provide as much ventilation as possible.
b. Receiving a Call.
c. Desert Climate.
(1) When the TALK REQUEST indicator lights, plug
(1) The main problem in equipment operation in
the send cord of the teletypewriter into the
desert areas is the large amount of sand, dust,
ORDER WIRE SEND jack, and the receive cord
or dirt that enters the chassis of the MD-
into the ORDER WIRE RECEIVE jack.
674(P)/G.
(2) Momentarily depress the TALK REQUEST
(2) Keep the equipment as free from dust as
pushbutton to send an acknowledgment signal
possible.
Make
frequent
preventive
to the distant operator.
maintenance checks (par 4-2). This equipment
(3) When the TALK REQUEST indicator lights to
does not require lubrication and should be kept
indicate that communications are completed,
free from oil and grease.
momentarily depress the TALK REQUEST
pushbutton to send an acknowledgment signal
3-5. Preventive Maintenance
to the distant operator.
To ensure that the modem is always ready for operation,
(4) Disconnect the teletypewriter equipment from
inspect it systematically to discover and correct defects.
the ORDER WIRE jacks, and momentarily
The necessary preventive maintenance checks to be
depress the TALK REQUEST RESET
performed are listed in paragraph 3-6.
Defects
pushbutton.
discovered during operation of the unit will be noted for
3-4. Operation Under Unusual Conditions
future correction to be made as soon as operation has
ceased. Stop operation immediately if deficiency is
Although the MD-674(P)/G retains its technical
noted during operation which would damage the
characteristics over a wide temperature and humidity
equipment. Records and reports of these checks and
range, adverse climatic conditions may affect operation.
services must be made in accordance with the
Observe the precautions given in a, b, and c below as
requirements set forth in DA Pam 738-750.
appropriate.
3-6. Operator's Preventive Maintenance Checks and Services Chart
NOTE
The checks in the "Interval" column are to be performed in the order listed.
B - Before operation
Item
Interval
Item to be inspected
No.
B
Procedure
Equipment is not ready/available if:
1
*
Modem performance check.
Equipment fails to support assigned mission.
Perform operational checks as described
in paragraphs 3-2 and 3-3.
*Do this check before each deployment to a mission location. This will permit any existing problems to be corrected
before the mission starts. The check does not need to be done again until redeployment.
Change 6
3-2
