TM 32-5835-005-14 & P
Section
V.
GENERAL
SUPPORT
TESTING
PROCEDURES
8-34. Operational Test Procedure.
8-35. Power Supply Test
a. Scope of Tests. To determine that
a. Connect a 230 VAC single phase
the Recorder/Reproducer is functioning
source to power input of the unit through
properly after troubleshooting or repair
appropriate cable. Line frequency may
actions, a series of operational tests
be anywhere from 50 to 400Hz.
is performed on a routine basis. If
recorder fails to meet the requirements
b. Vary line voltage between 218 and
of any test, refer to troubleshooting
241 VAC, observe that voltages listed
Table 8-3. and sequential troubleshooting
below remain within limits given.
procedure paragraph 8-7.
Power Supply Board (A1A7):
TP1= greater than +22 VDC, less
b. The following tests shall be per-
than +40 VDC
formed in the order listed.
TP2= +21 VDC 2 VDC
TP3= +15 VDC 1.5 VDC
(1)
Power Supply
c. Connect a 115 VAC source to power
(2)
Speed Accuracy
input of the unit through appropriate
(3)
Variable Speed
cable. Repeat step b, varying line
Wow/Flutter
(4)
voltage from 109 to 21 VAC.
Frequency Response
(5)
(6)
Reproduce Amplifier Output
d. Connect a 28V DC source to power
input of the unit through appropriate
Input Level and Automatic Gain
(7)
cable. Repeat step b, varying DC vol-
Control
tage from 22 to 30 VDC.
(8) Signal to Noise Ratio
(9) Erase Efficiency
8-36. Record/Reproduce Speed Accuracy.
(10) Crosstalk measurement
The measurement procedure described
NOTE
below must be made at 25 C ambient
temperature, 115 VAC source 60 Hz.
During operational testing procedure,
a. Connect counter and oscilloscope to
the following conditions/control set-
HEADPHONE jack. Insert into the unit a
tings are to be maintained unless other-
cassette test tape prerecorded with a
wise indicated.
3kHz .5% signal at 15/16 IPS."
b. Set AGC - MAN 1 switch to MAN
CASSETTE LOADED IN UNIT.
position. Adjust GAIN control 1 to
15/16 IPS TAPE SPEED.
maximum. Set SPEED CONTROL to 15/16
AGC-MAN CONTROLS IN MAN
IPS. Set CHANNEL SELECTOR switch to
POSITION.
position 1.
CHANNEL SELECTOR SWITCH TO
CHANNEL BEING OBSERVED.
c. Place unit into FAST FWD mode of
LOAD/UNLOAD LEVER TO STANDBY.
operation by pressing Fast Forward
600 LOAD ON HEADPHONE OUTPUT
push-button. Wind tape to approximately
JACK.
the middle of the tape.
ALL AUDIO OUTPUT MEASUREMENTS
d. Stop unit by pressing STOP push-
MADE AT HEADPHONE JACK.
button.
AUDIO GENERATOR CONNECTED TO
RCVR JACK OF BOTH CHANNELS;
e. Place unit into Reproduce mode of
MAINTAIN 0dB OUTPUT UNLESS
operation by pressing the REPRODUCE
OTHERWISE DIRECTED.
pushbutton. Observe and note the per-
centage of deviation from the basic
Refer to Figure 7-1 for location of
frequency of tape.
circuits referenced in the following
test.
8-23
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