JVC KD-A77 A User Manual

K D-A 77 AIBICIEI J/u
Main Adjustments
[I] Equipment and measuring instruments used for adjustment
1. Electrical adjustment
1) Electronic
voltmeter
2) Audio frequency oscillator
(range; 50 - 20kHz and output OdB with impedance
600fl)
3) Attenuator
4) Standard tapes for RECIPB
Maxell UD -
SF tape (for normal) }
TDK SA - SA tape (for Cr02) or equivalent
SCOTCH MET AFINE - 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)
TMT-6002N (for playback frequency response)
6) Resistors
1
oon (for measurement of the bias current)
600n (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.
[11] Mechanical adjustment
Head adjustment
KO-A77
Back-tension pad
Pad
(attached to the cassette) Tape
Clearance (A)
1. After installing the specified parts in the appropriate
positions:
A. Snug screw CD gently, then back off about two
turns. This makes the heads nearly horizontal.
B. Snug screw @ gently, then back off about one turn.
This will roughly position the tape in the center of the
tape path.
For
tightening screw @" use a home make screwdriver,
filed down to the specifications shown below. The same
screwdriver can be used to tighten screw (1).
Screwdriver
Pinch roller
Combination head
2. Make sure that the moving part of the erase head
assembly
moves smoothly around the pivot of screw @
and also confirm that there is enough clearance (A) in
the play mode.
3.
Next, make an operational adjustment. Load a C-1 20
cassette and adjust the height of the erase head by turn-
ing screw @. Watching that the tape does not curl at
the guides of both the combination and erase heads is
indication
of proper adjustment.
Correct
-1 Tape guide
t -Tape
Incorrect
f
Tap€ guide --, Tape guide
Tape l
__ ' _~-- Tape
No.4186
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JVC KD-A77 A Specifications

General

Brand	JVC
Model	KD-A77 A
Category	Cassette Player
Language	English