Technics RS-B765 - Page 15

Measurement Condition
¢ Rec. level control; Maximum
© Timer switch; Off
¢ MPX filter switch: off
¢ Bias-adjustment VR: Center
e Rec. balance control; Center
Mi MEASUREMENT AND ADJUSTMENT METHODES
e Rec. calibration adjustment; Center
¢ Dolby NR switch; Off
¢ Make sure heads are clean
e Make sure capstan and pressure roller are clean
¢ Judgeable room temperature 20+5'C (68+9° F)
Measuring Instrument
© EVM (Electronic Voltmeter) ¢ ATT (Attenuator)
¢ Oscilloscope ¢ DC voltmeter
© Digital frequency counter ¢ Resistor (600Q)
© AF oscillator
Test tape
¢ Head azimuth adjustment (8kHz, —20dB); QZZCFM
¢ Tape speed adjustment (3kHz, —10dB); QZ2ZCWAT
e Playback frequency response (315Hz, 12.5kHz, 10kHz,
8kHz, 4kHz, 1kHz, 250Hz, 125Hz, 63Hz, —20dB);
QZZCFM
¢ Playback gain adjustment (315Hz, 0dB); QZZCFM
¢ Overall frequency response, Overall gain adjustment
Normal reference blank tape ; QZZCRA
CrO, reference blank tape; QZZCRX
Metal reference blank tape; QZZCRZ
e Adjustment Points
OVERALL FREQUENCY RESPONSE
VR30I( Lh), VR302 (Reh) Line Line
out in
=
MAIN PC.B.
PLAYBACK GAIN ADy.
VR3 (Loh), VR4(Rch)
VR3 VR4
L302 L303
Qi IQ
VR302
VR301
OVERALL GAIN ADJ.
AC
BIAS
TRAP
ADV.
™
VRS
(Loh)
,VR6(
Rh)
Li(Leh),L2(Reh)
CHECKING THE EFFECT OF BIAS ADJ. VR
L303 (Lch), L302 (Reh)
RS-B755