JVC PC-70L - Page 13

PC-70 L/LB/LD/LS
{IIl] Cassette Amplifier Adjustment
Parts Side
VR201
Rec/P.B. Response Adj
101
FS Pattern
8 S P.B,Output Level Adj.
L101 R151 R251
Bias Frequency Adj.
Fig. 20
Cassette recorder section
,
Tape to Fr : -
Item bé-used Adjustment and check Adjustment point
Tt red
Playback output VTT664 Play the VTT644 and, when the L and R level difference is | R151 or R251
level (1 kHz) more than 2 dB, perform this adjustment. For the channel
with lower level, shortcircuit the slit pattern with R151 or
R251.
Playback frequency | VTT739 When playing VTT739 and assuming 1 kHz level at O dBs,
response 125 Hz shall be +1 dB +3 dB, and 8 kHz shall be +1 dB
+3 dB.
Bias frequency Connect a frequency counter to TP101 (on the H side of | L101
adjustment R101) and adjust L101 to obtain 68 kHz.
Recording and Apply signals — 20 dB under the reference input, and record | VR101 and
playback frequency and reproduce 1 kHz, 100 Hz and 8 kHz. Then adjust VR101 | VR201
response and VR201 so that 100 Hzis OdB +3 dB,
and 8 kHzis +1 dB +3 dB.
In this adjustment, the L and R difference when recording/
playing 1 kHz signal shall be within 3 dB.
Recording and Record and reproduce 1 kHz reference level signal and |
playback distortion measure the distortion. The values shall be within 3%.
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(No. 1543) 13