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DR-E34BK
DR-E34LBK
(1) Measuring instruments necessary for Adjustment
1.
Low frequency oscillator (Output of Odbs should be
5.
Recording standard tapes
obtain at the 600 ohm terminal at a frequency of SOHz
AC-513 (CrO2), TS-5 (SF) or equivalent. (Use the standard
~20kHz)
tape specified by JVC Audio Division.)
2.
Attenuator (600 ohm impedance)
6.
600-ohm impedance (for attenuator matching)
3.
Electric voltmeter
7.
Distortion factor meter (bandpass filter)
STANDARD TAPES
8.
Torque gauge : CTG-N (cassette type)
9.
VTT-703L(for head azimuth adjustment)
VTT-712
(for tape speed , wow & flutter)
VTT-724 (standard level)
C-120 tape (for checking the tape running)
(2) Adjustment and repairing the mechanism
(Adjust and check the mechanism before adjusting the electric circuit)
1) When the specified characteristic
cannot be obtained because of
head wear, cut wire, excessive
magnetization, etc., replace the
head and adjust the head azimuth.
Also, perform the adjustment of
the playback level, recording bias
current, recording level, etc.
Adjusting
Connect the output from the SPK OUT terminal
azimuth of
"to the voltmeter.(At about 1 volt)
rec/play head
. Play back VTT-703L
. Adjust screw A so that the output of the
voltmeter becomes maximum when PLAY > ) is
pressed.
4. Paint screw A and B with screw locking compound so they do not
come loose after adjustment.
voltmeter becomes maximum when PLAY
Maximum
( >) is pressed.
6. Adjust screw B so that the output of the
voltmeter becomes maximum when PLAY
Maximum
(<@ is pressed.
7. Paint screws A and B with screw locking 'compound so they
do not come loose after adjustment.
Measure the torque in the playback mode using | 30~ 65 g-cm
the torque measurement
cassette CTG-N.
Measure the torque in the fast forward mode
75 ~ 130 g-cm
by the same
procedure.
75 ~ 130 g-cm
Maximum
2
~~
When there is the difference of
more than 3~
4 dB between left
and right output levels, replace the
!
head to avoid complaints.
5. Adjust screw A so that the output of the
When the standard torque cannot be
obtained, clean or replace the take-
up disc assembly.
Playback torque
When the standard torque cannot be
obtained,
1) Clean the capstan belt, rim of the
fly-wheel, motor pulley, etc.
2) Change the belt, idler, etc.
Fast forward
torque
Wow & flutter
1-26
(No. 20162)
When
the standard torque cannot be
obtained, clean the motor pulley,
capstan, rim of the fly-wheel, rim of
the supply reel disc, etc.
Measure the torque in the rewind mode by the
same procedure.
As a complaint may occur if the wow
& flutter fluctuates by 0.1% even
though it is allowed in the standard,
repairing is required.
Play back VTT-712 and attach the wow & flutter
meter to the SPK OUT terminals of this unit;
its reading should be within 0.16% (WRMS).
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