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L-CH/R-CH output balance adjustment
LINE QUT
VIVM
Oscilloscope
L-ch peak level
R-ch peak jevel
ee
ee,
L-CH/R-CH phase adjustment
4. Make connections as shown in fig. 5.
Record/
playback head
Horizontal
Vertical
Record/playback
head
[=
Test
Tape speed accuracy
3. Measure this frequency.
f-3,000
Tape speed accuracy = 3000
*~100(%)
where, f = measured value
ack mode
nen
oan
—
ca
Digital frequency counter
Standard value: +1.5%
Tape speed fluctuation
Make
measurements
in same
manner
as above
(beginning,
middle
and end of tape), and
determine
the
difference between maximum and minimum values and calculate as follows:
f,—f
Tape speed fluctuation = 3000 x100(%)
f, = maximum value, f, = minimum value
Standard value: Less than 1%
. Test equipment connection is shown in fig. 2.
. Playback
the frequency
response
portion
of test tape
(QZZCFM).
4. Make measurements for both channels.
Playback frequency response chart
To toe
COS
COMI Sarr
COI ASST
COT
re
COR
IE TSE
63Hz 100Hz
200H2
315Hz 500Hz
1 KHz
4KHz
12.5KH2
+5dB
+4dB
+308
+2dB
+208
0d8
0d8
~ 20B
-3d8
-2d8
-4dB
~5dB
¢ Test tape...QZZCFM
1. Test equipment connection is shown in fig. 2.
3. Make measurements for both channels.
Standard value: 0.28V [0.4V+1dB: at LINE OUT jack]
Adjustment
1. If the measured value is not within the standard, adjust VR1 (L-CH) or VR2 (R-CH) (See fig. 1).
2. After adjustment, check "Playback frequency response" again.
@ Erase current
Condition:
Equipment:
e Record mode
°VTVM
¢ Metal tape mode
e Oscilloscope
Erase head
. Test equipment connection is shown in fig. 9.
. Place UNIT into metal tape mode.
& WN
Voltage across resistor R84
R84 (192)
Erase current (A) = ee
VIVM
Oscilloscope
Adjustment
e If the erase current is more than 165mA, cut the jumper wire (See fig. 1).
Note:
Before
measuring
and
adjusting,
the
overall
frequency
response make sure of the playback frequency response (For
the method of measurement, please refer to the playback fre-
quency response).
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