Sony TC-377 Service Manual page 10

3-2. ELECTRICAL ADJUSTMENTS/
MEASUREMENTS
Precaution:
I...Clean- the. following parts with an alcohol
: moistened swab:
record head
. playback head
pinch roller
rubber belts
erase head idlers
capstan tape guides
2. Demagnetize record head and playback head
with a head demagnetizer.
3. Do not use magnetized screwdriver for adjust-
ments,
4. After adjustments, apply locking paint to the
adjusted parts.
5, Adjustments should be performed in the order
given in this service: manual.
6. Adjustments and. measurements should be
performed for both L-CH and R-CH with rated
' power supply voltage unless otherwise specified.
Test Equipment/Tools Required:
audio oscillator (af osc)
VTVM
400 Hz bandpass filter
attenuator (6002)
non-magnetic screwdriver
wow meter
distortion meter
oscilloscope
resistOrs ......... 6002 (4W), 3002 (AW)
10k2 (4W), 100k2 (4W)
SONY test tape
J-19-F]
"CEP EER z
ever esi] 10] 0] v0] 10] "i0] "io 0
blank tape (completely erased with bulk eraser)
| SONY super 150 ,
SONY SLH
Note: When connecting the measuring equip-
ments to the input or the output jack
of the machine, take the impedance
matching correctly.
| mon wl
Rated Output Level!
(Load impedance)
Rated Input Level
{Input Impedance)
MICRO- {| -60 dB, 0.78 mV
PHONE (6002) LINE
LINE | -10dB,0.25v | OUT
IN (10k)
RECORD VOLUME control should be set as follows
unless otherwise specified.
LINE RECORD VOLUME
Position to obtain 0dB (0.78 V) LINE OUTput for
1kHz, -10dB (0.25V) LINE INput with MIC
RECORD VOLUME set to the minimum position
and MONITOR switch set to SOURCE position.
MIC RECORD VOLUME
Position to obtain 0dB (0.78 V) LINE OUTput for
1kHz, -60dB (0.78mV) MICROPHONE input
with LINE RECORD VOLUME set to minimum
position and MONITOR switch set to SOURCE
OdB, 0.78V
(100k)
position.
af osc
VTVM
70kQ. (for
© | .attenuator
LINE IN only)
199 kQ. ze)
"O—=o O =
stood? = Fe
[ |
60022 WicROPHONE 'LINE OUT
1 kHz, -60 dB (0.78 mV)
LINE IN
1 kHz, -10 dB (0.25V)
Note on replacing the heads:
1. Erase Head Removal
When removing the erase head from the
head deck, remove the two screws shown
with 4.
(Do not remove the three screws shown
below x)
. Record or P.B. Head Removal
When removing the record or the p.b. head,
remove the respective angle adjusting screws.
(Do not turn the screws saree the angle
adjusting screws.)
record head