AT&T Bell System Plant Series Adjustment Procedure page 5

SUPPLY REEL
TACHOMETER
PULLEY-------...J~!,
TAPE GUIDES
TAKE-UP REEL
TACHOMETER
PULLEY
VACUUM CHAMBER
GLASS COVER
GLASS COVER SPRING CLIP (TYP)
ISS l , SECTION 034-368-70 l
PHOTOSENSE HEAD
HEAD COVER
ASS EM BLY
HEAD COVER
ASSEMBLY
CAPSTAN
STOP
TAPE CLEANER
TAKE-UP VACUUM CHAMBER
Fig. 3-Partial Front View of Tape Transport Showing Tape Path Components
(b) The transport access door hinge assembly
and the mounting panel hinge should be
lubricated at 6-month intervals.
2.04
Demagneli=alion: All ferrous parts and
components in the tape path are demagnetized
by the manufacturer and should require no further
attention.
2.05
Reel Brake Torque (Tension) for Supply
and Take- l'p Reels: Braking re4 uirements
on each reel shall be measured while power is
applied to the reel brake. Requirements to be
met are shown in Table B. Cse the 19B gauge.
To check the tension re4uirement of either reel,
proceed as follows.
(1)
Wrap one end of a nylon cord several turns
clockwise around the hub of the empty reel
(Fig. 5).
(2) Attach the 79B gauge to a loop in the free
end of the cord.
Nole: Before using the 798 gauge, refer to
Section 020-010-711 for information pertaining
to the proper application of the gauge.
(3) Pull out LOAD switch operating rod (Fig. 2)
and apply power to the recorder.
(4) Pull the tension gauge (Fig. 5) in a direction
in line with the wraps of cord on the reel
hub. Pull smoothly and steadily until the reel
rotates and, with the reel turning smoothly,
observe the gauge reading.
2.06
Control Unit Power Supply: The control
unit contains a power supply which provides
+
12 and -12 volts of power for the control unit.
Potentiometers located on printed circuit board
PSD (Fig. 6) are used to regulate the voltage.
Potentiometer R9 regulates
+
12 volts and
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