Overall S/N Check; Tuner System Adjustment; Separation Adjustment; Parts Arrangement Diagram For Adjustments - Sony SLV-L56AR Service Manual

4. Overall Level Characteristic and Distortion Factor
Check
Purpose:
Check the record level, play level, and distortion factor against
the reference input.
Mode REC and PB (SP mode)
Signal 400 Hz, –7.5 dBs
Measurement point Audio output terminal
Measurement equipment Audio level meter and distortion
factor meter
Specified value Playback level: –7.5 ± 2 dBs
Distortion factor: 4% or less
Confirmation Method:
1) Supply an audio signal of 400 Hz, –7.5 dBs simultaneously to
both L and R channels of Audio Line Input.
2) Make recording
3) Play back a recorded portion.
4) Confirm that a playback level is –7.5 ± 2 dBs.
5) Confirm that a distortion factor is within 4%.

5. Overall S/N Check

Purpose:
Confirm that the S/N is within the specification.
Mode REC and PB (SP mode)
Signal Short
Measurement point Audio output terminal
Measurement equipment Audio noise meter
Specified value –46.0 dBs or less
Confirmation Method:
1) Connect both L and R channels of audio line input to the GND.
2) Start recording.
3) Play the recorded part to confirm that the noise is below –46.0
dBs.
2-5.

TUNER SYSTEM ADJUSTMENT

[Connection]
Audio level
meter
Up channel
47 k
convertor
VTR
RF IN
Fig. 7-2-6
2-5-1. Separation Adjustment (SLV-L76HF/L86HF)
Purpose:
Mixed audio signal separate Lch and Rch.
Mode E-E
Signal VIDEO:
color bar
(87.5% modulation)
AUDIO:
L 1 kHz 100% modulation
R no signal
ELECTRIC FIELD:
60–80 dBs/75 W Tem
Pin !™ of IC750
Measurement point
Measurement equipment Audio level meter
Adjusting Element RV750
Specified value –9.9 ± 0.2 dBm
(700 ± 14 mVp-p)
7-5
2-6.

PARTS ARRANGEMENT DIAGRAM FOR ADJUSTMENTS

MA-323 BOARD (Side A)
CN501
1 4
CN431
2
1
IC750
13
1
RV750
US MPX SEP
HS-921SF1 BOARD (Side A)
RV201
6V ADJ
CN201
1 9
SR-708 BOARD (Side A)
VR201
6V ADJ
1 CN201 9
JS140
7-6 E