Sony TC-KB920S - SECTION 4 ELECTRICAL ADJUSTMENTS; Head Azimuth Adjustment; Standard Levels and Test Tapes

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SECTION 4
ELECTRICAL ADJUSTMENTS
Note: The adjustment should be performed in the order given in the ser-
vice manual. As a rule, adjustments about playback should be per-
formed before those about recording.
The adjustments should be performed before for both L-CH and R-
CH.
• Switches and controls should be set as follows unless otherwise
specified.
DOLBY NR, MPX FILTER switch: OFF
MONITOR switch: Tape
• Standard Record:
Deliver the standard input signal level to the input jack and set
the REC LEVEL control to obtain the standard output signal
level.
– Record Mode –
Standard Input Level
input terminal LINE IN
source impedance 10 kΩ
input signal level 0.5 V (–3.8 dB)
Standard Output Level
output terminal LINE OUT
load impedance 47 kΩ
output signal level 0.5 V (–3.8 dB)
Test Tape
Type Signal Used for
P-4-A100 10 kHz, –10 dB Azimuth Adjustment
P-4-L300 315 Hz, 0 dB Playback Level Adjustment
WS-48B 3 kHz, 0 dB Tape Speed Adjustment
+
–
set
47 k
Ω
LINE OUT
LINE IN
600
Ω
10 k Ω
attenuator
AF OSC
level meter
Record/Playback Head Azimuth Adjustment
Procedure:
1. Mode: FWD playback
2. Turn the adjustment screw for the maximum output levels. If
these levels do not match, turn the adjustment screw until both
of output levels match together within 1 dB.
3. Phase Check
Mode: playback
4. After the adjustment, lock the screw with locking compound.
Adjustment Location: Record/Playback head
+
–
set
47 k
Ω
LINE OUT
level mete
r
Test tape
P-4-A100
(10 kHz, –10 dB)
Screw
position
L-CH
peak
within
1dB
output
level
L-CH peak
R-CH peak
within
1dB
angl
e
R-CH
peak
+
–
V
H
+
–
Screen pattern
Good Wrong
in phase 45
° 90 ° 135 ° 180 °
LINE OUT
set
R-CH
L-CH
47 k
Ω
47 k Ω
oscilloscope
test tape
P-4-A100
(10 kHz, –10 dB)
Adjustment screw
0 dB=0.775 V