Erasure Current Adjustment; Bias Trap Adjustment; Recording Bias Adjustment - Pioneer CT-9R Service Manual

5.5 Erasure Current Adjustment
Setting:
Mode
Test tape
INPUT level control . . .
AC mV meter
Procedure:
Adjust the VR302 so
reads 160mV.
Fig. 5-10 Erasure current adjustment
5.6 Bias Trap Adjustment
Setting:
M o d e
. . . . R e c o r d
MONITOR switch . .. . TAPE
OUTPUT level control . Max.
AC mV meter
. . OUTPUT terrninals
Oscilloscope ....
OuTPuTterminals
Procedure:
Adjust the L1701 (Lch) and L17O2 (Rch) so
that the AC mV meter reads minimum level.
5.7 Recording Bias Adjustment
Setting:
M o d e
. . . . R e c o r d
MONITOR switch . .. . SOURCE
I n p u t S i g n a l
. . . . 6 . 3 k H z , - 2 O d B v ( 1 0 0 m V )
OUTPUT level control . Max.
Test tape
. STD-608A
AC mV meter
. . . OUTPUT terminals
VR303, VR304
. Min.
Procedure:
1. Adjust the INPUT level control so that the
AC mV meter reads - 14dBv (199mV).
2. Set the MONITOR
switch to the TAPE
position.
3. Adjust the VR303 (Lch) and VR304 (Rch) so
that the AC mV meter reads the maximum
output level, and then bring back until the
output level drops 2dB (Fig. 5-12\.
As VR303 and VR304 interact with one another,
carry out the above procedures by alternatively
and repetitively adjusting VR303 and VR304.
F i g . 5 - 1 2 B i a s s e t t i n g p o i n t
Record
STD-604
Min.
TP2 of the Mother
assembly
that the AC mV meter
o.ol u,o.l oF" r,os
at MoNtroR sw
. . . . T A P E
See Fig. 1 1-24.
3 4
Fig. 5-1 1 Bias trap adjustment
F i g . 5 - 1 3 R e c o r d i n g b i a s a d j u s t m e n t