JVC KD-V6 - Main Adjustments

KD-V6A/B/C/E/J/U |
Main Adjustments
= =
WN
E
adjustment
. Measuring instruments for adjustment
. Audio generator (range: 50 Hz — 20 kHz and output of
O dB with terminal impedance of 600 ohms)
. Attenuator (with impedance of 600 ohms)
. Electronic voltmeter
. Reference tapes
TMT 702 (for head azimuth adjustment) 14 kHz,
VTT712 (for tape speed or wow and flutter adjustment)
300 Hz,
VTT664 (reference level) 1 kHz,
VTT739 (playback frequency response),
TMT6447 (for music scan),
TMT6448 (for music scan)
. Mechanism adjustments and repairs
oOo ON Oo
. Recording reference tapes
The reference tapes should be TS-5 (UD), TS-6 (SA) and
TS-7 (ME) or their equivalent.
(Use the designated reference tape of this division.)
. Resistors 600 ohms (for attenuator matching)
. Distortion meter (band pass filter)
. Torque gauge (cassette) CTG-N
. C-120 tape (for confirming the tape |
For mechanism
transport)
adjustment
Notice: The VTT712 has improved accuracy and TMT702
is newly added. The substitution of BTT658
(10 kHz) is possible.
(Mechanism adjustment or confirmation are required before performing the electrical circuit adjustment.)
1) Make sure that the moving part
of the erase head assembly move
smoothly around the pivot of
screw Q) and also confirm that
there is clearance as shown
in the figure during the playback
mode.
2) Check the tape transport as fol-
lows. Adjust the height of the
erase head with screw (2) while
observing curl in the tape trans-
port with C-120 tape and adjust
so no curl will appear in the tape
guide section of the play head or
the erase head.
rase head
Pad Clearance ®
Tape Tape Tape
guide guide guide
i Tape ls Tape Tape
a
Correct Incorrect
Lock the screws after adjustment.
djusting | Standard
A
point
Replacement and adjustment of record head and play head
since certain screws have been precisely adjusted in the
This deck has three independent heads and the head units
are completely separate. However, they are assembled and
adjusted on a single head board, therefore they can be dealt
wi
th
th as one unit in principle. Accordingly, replace or adjust
e head assembly when any head is defective. In addition,
Remarks
Be sure to perform this adjustment after
erase head replacement.
Screwdriver
Ye 1—2 mm
2-—2.5 mm
Notes:
e After adjustment, confirm by ear how
effectively the erasure is performed
using a metal tape.
e After replacement of the erase head,
play or record head, loosen the associ-
ated wires and clamp a new head then
confirm that the new head movement
is normal.
factory, care should be taken when handling them as well as
referring to the following adjustment items (1. Reference
dimensions, 2. Screw explanations, 3. Adjustment methods).
1. Reference dimensions
The reference dimensions of record head and play head
are shown in Fig. 7. After checking or replacing the head
assembly because of characteristic deterioration, confirm
that there is no big disagreement.
. Screw explanations
The screws marked O require adjustment when repairing.
The screws marked X are basically required not to move
when repairing.
(1) is the head base fixing screw.
(2) and (3) marked X are the play head fixing screws (for
adjusting the relative position to the record head).