Technics RS-676US

15
ITEM MEASUREMENT & ADJUSTMENT REMARKS
Level Meter 1. Test equipments connection is shown in fig. 22. * Record Mode
Equipments: 2. Supply 1kHz signal (-7dB) from AF oscillator, through | * Balance Control
* VTVM ATT, to LINE IN jack. ...Center
* Oscilloscope 3. Adjust record level control VR so that monitor level at
* AF Oscillator LINE OUT becomes 0.42 V.
* ATT 4. Adjust VR15 (L-CH), VR16 (R-CH) so that VU meter indi-
cates 0 VU (See adjustment parts location on page 19).
Overall Distortion 1. Test equipments connection is shown in fig. 25. * Record Level Control
Equipments: 2. Supply 1 kHz signal to LINE IN and adjust ATT so that out- «MAX.
* Distortion Meter put level at LINE OUT indicates 0.42 V (—7 dB). -
* AF Oscillator 3. Make recording.
*
ATT
4.
Play
back,
and
measure
distortion
factor
of
output
signal.
5. When the distortion factor does not satisfy the standard,
* Oscilloscope
* Test Tape (Reference
Blank Tape)...C-RA
check the bias current. When the bias current is lower
than standard, distortion will increase.
Care should be exercised in the adjustment because the
bias current also has an influence on the overall frequency
response. Refer to ‘The Overall Frequency Response” and
“The Bias Current Adjustment”.
Fig. 25
Standard Value:
less than 2%...... Normal
less than 3.2%...CrO2