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7970B/7970C
Performance Checkout
SECTION III
PERFORMANCE CHECKOUT
3-1.
I NTRODUCTI ON.
3-2.
This section provides checkout instructions to ver-
ify that the tape unit conforms to published performance
specifications. The test procedure assumes that the follow-
ing general conditions apply at all times unless specific in-
structions to the contrary are stated as part of a test routine.
3-3.
TEST EQUIPMENT REQUI RED.
3-4.
For the purpose of this procedure, it is presumed
that the person conducting the test will be using either a
computer or an off-line test set that is capable of meeting
the following requirements. It is also presumed that operat-
ing instructions for the equipment is provided by documen-
tation applicable to the equipment.
a. Provides all standard functional commands.
b. Responds to all status outputs.
3-5.
An
HP 13191A Control and Status Test Board is
available as a service accessory and will meet the needs for
all adjustments. Computer operation is also suitable. The
following electronic test instruments (or equivalent) are
also required:
a. HP 140A Oscilloscope with HP 1421A Time Base
Generator.
b. HP 1421A Dual-Trace Preamplifier (for HP 140A).
c. HP 5245L Counter with HP 5265A Digital Volt-
meter Plug-In.
3·6.
In addition to the listed test equipment, a trans-
port test tape HP part number 5080-4525 that generates
various signals for accurate speed measurements is required.
3-7.
CHECKOUT PROCEDURES.
3-8.
Performance checkout procedures for the tape unit
consist of:
a. Preliminary Power-Off Checks.
b. Operator Control Checks.
Part 2
c. Service Switches and Accessory Checks.
d. Tape Path Evaluation.
e. Power Supply Voltage Checks.
f. Tape Speed and Capstan Servo Checks.
g. Transport Function, Motion, and Status Checks.
3-9.
PRELIMINARY POWER-OFF CHECKS.
3-10.
Preliminary power-off checks are performed as
follows:
a. Tape Rollers: The tape rollers must operate freely
and have no end play.
b. Head Crosstalk Shield: The head crosstalk shield
should operate freely and should have clearance between
face of head and shield (room to slip a punched card thick-
ness without binding).
c. Tension Arm Limit Switches: The three limit
switches associated with the tension arms must operate
when the arm is approximately 1/8 inch from the rubber
stop. The roller on the switch arm should be approximately
on the center of the arm when the arm is fully against the
stop. There should be positive travel of the switch lever be-
yond the point at which it actuates the microswitch. The
check can be made audibly if ambient noise level permits,
or with an ohmmeter if room noise is too high.
d. Write Enable Sensing: The write enable sensing
finger nominal location dimensions should be as follows:
(1)
The distance between the outside surface of
the write enable sensing finger and the out-
side flange diameter of the reel turntable
should be 3/32-inch (nominal).
(2)
In the file protected position (inoperative),
the dimension between the outer tip of the
sensing finger and the outer face of the reel
turntable should be 3/16-inch (nominal)
above the turntable surface.
(3)
In the write enable position (with solenoid
energized) the outer tip of the sensing finger
should be 1/16-inch below the turntable sur-
face.
(4)
The sensing finger must not touch the turn-
table under any condition.
3-1
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