Sony TC-K890ES - Record;Playback Heads Vertical Adjustment; Playback Level Adjustment; Erase Current Adjustment

TC - K222ESA/K890ES |
Record/Playback Heads Vertical Adjustment
Procedure:
1. Mode: Playback
Standard adjustment tape
P-4-A100
(10kHz, -10dB)
Line output
2. Adjust the adjustment screws so that L-CH and R-CH
outputs become maximum. If the maximum output points
of L-CH and R-CH do not coincide, adjust the screws
so that the outputs agree with each other within 1dB from
the maximum output value in each channel.
L-CH
peak
1dB or less
R-CH
peak
Adjustment screw ,
position L-CH R-CH Angle °
peak oak adjustment
P screw
3. Checking of phases
— Playback state —
Standard adjustment tape
P-4-A100
(10kHz, -10dB)
L-CH
R-CH
Line output
4. Check that the difference between L-CH and R-CH >
phases is in the same phase - 90°.
Oscilloscope Lissajou's figures
ODO@OO
Same phase 45° 90° 135° 180°
No good
Good
Adjustment Location:
Adjustment. screw
Playback Level Adjustment
Procedure:
1. Playback state
Standard adjustment tape
P-4-L300
(315Hz, OdB)
Line output
Adjust RV1i01 (L-CH) and RV201 (R-CH) to satisfy the
following specifications.
Adjustable limits:
Line output level: 0.30 to 0.33V
(-7.2 to —8.2dB)
Level difference between channels: 0.5dB ot less Check that,
by repeating playback and stop, the line output level does not
change.
Erase Current Adjustment
Procedure:
1. Mode: record
t tape
Frequency counter VIVM ener Teas
2. Adjust RV553 so that VTVM indicates 110mA (erase
current 1!10mA).
3. Check oscillation frequency at that time.
Adjustable limits:
Erase current: 110 £2 mA
Oscillation frequency: 160 + 6kHz