JVC KD-A66 Service Manual

KD-A66A/B/C/E/J/U
Main Adjustments
[1] Equipment and measuring instruments used for adjustment
1. Electrical adjustment
1) Electronic voltmeter
2) Audio frequency oscillator pete
(range: 50—20 kHz and output 0 dB with impedance Audio Freq. Osc. OMe p
6002) Attenuator tg
3) Attenuator
4) Standard tapes for REC/PB
Maxell UD — SF tape .
TDK SA - SA tape | or equivalent
SCOTCH METAFINE — Metal tape
5) Reference tapes for playback (JVC Test Tape)
VTT-658 (for head azimuth adj.)
VTT-656 (for motor speed, wow flutter adj.)
VTT-664 (for Reference Level 1 kHz)
VTT-675N (for playback frequency response)
6) Resistors
1002 (for measurement of the bias current)
6002 (for attenuator matching)
2. Mechanical adjustment
1) Gauge for checking the head position.
2) Torque gauge
3) Blank tape (C-120) for tape running checker.
OUTPUT
LINE OUT
[11] Adjustment and repair of the mechanism
TROUBLESHOOTING HINTS 2. Tape-to-head contact adjustment
1. Azimuth adjustment and head replacement 1) Turn the adjusting screw for 0°
1) Remove the wires of the control switches from the aligning the erase head until it
wire clamps after having removed the top cover. stops. Then, turn the screw in é
2) Remove 3 screws positioned below the control the reverse direction by 225° ras
switches (on the bottom of the deck) and pull the (a 5/8 revolution).
control section forwards. 2) Check the tape-to-head contact using a C-120 tape
3) With the control section pulled out, azimuth adjust- having pads.
ment and/or head replacement can be performed. 3) Check it again with a Metal tape.
With the JVC cassette deck series of KD-A6, KD-A5 Checking method:
and KD-A8 models, the adjustment of replacement Record a 400 Hz or 1 kHz signal with O VU + 20 cB.
can be performed more easily than with conventional Erase the recording. Checking if the erasing is satis-
cassette decks which require removal of the entire factorily performed.
mechanical
section
for
the
adjustments
and/or
replace-
4)
After
adjustment,
apply
screw
bond
on
the
adjusting
ments. screw to prevent its loosening.
(Adjust the mechanism or confirm that it is in normal operating condition prior to the adjustment of the electrical circuit.)
point value
Adjusting 1. Connect an electronic voltmeter to Screw ® Maximum lf the head is worn, disconnect-
record/playback the LINE OUT terminals. ed or exceedingly magnetized so
head position 2. Playback the VTT-658 test tape. as not to provide the necessary
3. Adjsut the head angle with the characteristics, replace it with a
screw @® until the reading of the new one.
electronic voltmeter becomes maxi- After replacement, the head
mum for both channels. position adjustment as well as the
4. After adjusting, set the screw with playback level adjustment, the
screw bond. bias current adjustment and the
recording level adjustment are
all necessary.
If the output difference between
the left and right channels exce-
eds 3—4 dB, the head is defect-
ive.
Replace it with a new one.
—13— No. 4193

JVC KD-A66 Specifications

General

Brand	JVC
Model	KD-A66
Category	Cassette Player
Language	English