Advertisement
RS-B14
Q
Head azimuth
Condition:
Equipment:
adjustment
* Playback mode
• VTVM
е Normal tape mode
* Oscilloscope
* Test tape (azimuth)...QZZCFM
Playback mode
VTVM
Oscilloscope
. Playback the 8kHz signal from the test tape (QZZCFM).
Fig.
2
Adjust screw (B) in fig. 3 for maximum output L-CH and R-CH levels.
Ig.
When the output levels of L-CH and R-CH are not at maximum at the
c
Record/playback
same point adjust as follows.
ee
ngad
. Turn screw (B) shown in fig. 3 to find angles A and C (points where
/
peak output levels for left and right channels are obtained).
Then,
A
locate angle B between
angles A and C, i.e., point where L-CH and
Screw (8)
R-CH outputs are balanced. (Refer to figs. 3 and 4.)
Fig. 3
L-ch peak level
R-ch peak level
1 Ж
ГА
4. Make connections as shown in fig. 5.
5. Playback the 8kHz signal from the test tape (QZZCFM).
Adjust screw (B) shown
in fig. 3 so that pointers of the two VTVMs
swing to maximum and a lissajous waveform as illustrated in fig. 6 is
obtained on the oscilloscope.
Record/
Oscilloscope
playback head
Playback
D
mode
LINE OUT
Vertical
Horizontal
Fig. 6
Fig. 5
g
Ө
Tape speed
Condition:
Equipment:
* Playback mode
* Digital frequency counter
* Test tape... QZZCWAT
head
. Test equipment connection is shown in fig. 7.
о
. Playback test tape (QZZCWAT 3,000Н2), and supply playback signal
о
at
to the digital frequency counter.
Playpack те
на тТаШЕНЕ conni
. Measure this frequency.
. On the basis of 3,000Hz, determine value by following formula:
Fig. 7
Tape speed accuracy = TOO
100(%)
where, f = measured value
. Take measurement at middle section of tape.
Standard value: «1.596
. If measured value is not within the standard value, adjust it by using the tape speed adjustment VR shown in
fig. 1.
Note: Please use non metal type screwdriver when you adjust tape speed accuracy on this unit.
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 = 3.000 х100(%)
fi = maximum value, f, = minimum value
Standard value: Less than 1%
Advertisement
