Audio System Adjustment; Ace Head Adjustment; E-E Output Level Check; Overall Output Level And Distortion Factor Check - Sony SLV-478 Service Manual

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2-5.

AUDIO SYSTEM ADJUSTMENT

• For the adjustment of the audio system, perform in the SP mode
if there is no special notes. Use the alignment tape.
[Connecting Instruments]
Audio line OUTPUT L/R
Audio line INPUT L/R
Audio
oscillator
600 Ω
Attenuator
Fig. 6-2-12.
• Adjust in the SP mode if there is no special indications.
• Perform the adjustment setting the switch on the following
positions.
• INPUT SELECT switch .............................. LINE or LINE 1
[Adjustment Method]
1. ACE head adjustment.....Refer to the VHS mechanical
adjustment manual (S MECHANISM)(9-921-647-11).
2.

E-E output level check

3.

Overall Output level and distortion factor check

4.

Overall noise level check.

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2-5-1. ACE Head Adjustment

Refer to the VHS mechanical adjustment manual
MECHANISM)(9-921-647-11).
2-5-2. E-E Output Level Check
Mode E-E
Signal 400Hz, –7.5dBs : CJ570
Measurement point CJ570
Measuring instrument Audio level meter
Specified value –7.5 ± 2dBs
[Check Method]
1) Input signal of 400Hz and –7.5dBs to the CJ461 L/R.
2) Check that the audio output level is –7.5 ± 3dBs.
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Audio level
meter
or
distortion
meter
47 k Ω
VTR
(Remote commander)
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2-5-3. Overall Output Level and Distortion Factor
Check
Mode
Signal
Measurement point
Measuring instrument
Specified value
[Check Method]
1) Input signal of 400Hz and –7.5dBs to the audio input.
2) Record signal.
3) Playback the recorded portion.
4) Check that the output level is –7.5 ± 3dBs.
5) Check that the distortion factor is 4.0% or less.
2-5-4. Overall Noise Level Check
Mode
Signal
Measurement point
Measuring instrument
Specified value
[Check Method]
1) Record.
2) Playback recorded portion.
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3) Check that noise level is – 45.5dBs or less.
2-6.

TUNER SYSTEM ADJUSTMENT (HiFi MODEL)

2-6-1. Separation Adjustment (MA-317 Board)

Mode
Signal
Measuring instrument
Measuring point
Adjusting element
Specified value
[Adjustment Method]
1) Connect an audio level meter to LINE OUT L channel via HPF.
2) Feed the RF signal from RF IN terminal.
3) Adjust with RV731 so that the output level satisfies the specified
value.
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Self-record playback
400Hz, –7.5dBs : CJ570
CJ570
Audio level meter and Distortion
meter
Playback Level: –7.5 ± 3dBs
Distortion: 4.0% or less
Self-record playback
No signal (Insert a shorting plug into
the Audio LINE IN terminal)
CJ570
Audio level meter
– 45.5dBs or less
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E-E
RF signal
Video : Color bar
white (100%) modulation
Audio : L: 400Hz, R: 2kHz
30% modulation
Electrical field:
60-80dBm/75Ω terminated
Audio level meter
LINE OUT L
RV731
2kHz component minimum
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