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6.
6.1.
Note:
ELECTRICAL ADJUSTMENTS AND MEASUREMENTS
Adjustment and Measurement Instructions
Electrical adjustment should be performed after mechanical adjustment is completed.
SIGNAL SOURCE
OUTPUT
CONNECTION
MODE
'
3 kHz Speed and Wow/Flutter
| Frequency Counter to
Playback
Tape Speed Adjustment | +46 (DAO9006A)
Output Jacks
Eq. SW — 70 us
ADJUSTMENT
L
REMARKS
Capstan Motor
Governor P.C.B.
Adjust VR501 to obtain 3 kHz +0.5%.
(VR501 is incorporated in the capstan motor.)
VTVM to TP101, TP201
on Main P.C.B.
Meter Level Calibration
400 Hz to Input Jacks
Record, Pause
VR501
r
1. Feed in 400 Hz, then adjust the Input Level controls to obtain 90 mV —0.4
dB on the VTVM.
2. Adjust VR701
(VR801) so that the O dB segment of the level meter starts
iNuminating.
3. Adjust the Input Level controls to obtain 90 mV on the VTVM, then de-
Main P.C.B.
VR701, VR801
eS
crease the generator output level by 20 dB.
. Check to insure that the segment for —20 dB illuminates.
Adjust the Input Level controls to obtain 600 mV on the
VT VM.
=
F
19 kHz +100 Hz to
Record, Pause
Main P.C.B.
2. Set the MPX
Filter switch to IN,
then adjust L103
(L203) to obtain the
Vv
t Jack
'
3
MRIS Ribter Ae IUSEmSTES
ts sidaeks
TV NIE OU EU
Each
MPX SW — OUT/IN
L103, L203
minimum reading on the VTVM (minimum reading will be less than —30
dB).
Playback
ZX SW — OUT
A
Adjust the Height Gear to obtain minimum
readings of both channels on the
Record/Playback Head
1 kHz Track Alignment
SX/EX SW — SX
F
;
:
:
t
t Jack
Height G
oe
Track Alignment
Tape (DA09007A)
VTVM
to Output
Jacks
Eq. SW — 70 us
eig'
ear
pbc
ia Pea
ae
Head
Height Adjustment
and Azimuth
Dolby NR SW — OFF
9
ms
3
MPX SW — OUT
Record/Playback
Adjust the Record/Playback
Head
Azimuth
Alignment
Screw to obtain maxi-
Record/Play
back Head
15 kHz Azimuth Tape
VTVM to Output Jacks
Same as above
mum
readings of both channels on the VTVM. Refer to '"'Record/Playback Head
Height Adjustment and Azimuth Alignment"' in item 4.8.
Note:
Repeat steps 4 and 5 one or two times to obtain optimum performance.
Head Azimuth
Alignment Screw
Azimuth Alignment
(DA09004A)
Playback Level
400 Hz Level Tape
Calibration
(DAO9005A)
VTVM to TP101, TP201
on Main P.C.B.
SEE: BS PONE
Main P.C.B.
VR101, VR201
Adjust VR101
(VR201) to obtain 90 mV on the VTVM.
400 Hz Level Tape
(DAO9005A)
10 kHz PB Frequency Tape
(DA09003A)
15 kHz PB Frequency Tape
(DA09002A)
20 kHz PB Frequency Tape
(DA09001A)
Playback Frequency
Response Adjustment
Same as above
VTVM
to Output Jacks
VR7OL(VR8OI)
Fig. 6.1
Fig. 6.2
2.
Meter Level
3.
MPX Filter
20
1. Load a 400 Hz level tape and play it back.
2. Load
10 kHz, 15 kHz and 20 kHz PB frequency response tapes and adjust
the record/playback head azimuth to obtain maximum
levels on the VTVM
with each tape.
3.
Read the maximum
levels with each tape and check to insure that the levels
Main P.C.B.
against the 400 Hz level tape are within the following ranges.
R111, R211
If not, obtain satisfactory results by shorting R111
(R211) or R110 (R210).
R110, R210
10 kHz (-20 dB)
0 dB to +2 dB
15 kHz (-20 dB)
OdB to +3 dB
20 kHz (—20 dB)
OdB to +4 dB
Check to insure that the difference in level between 10 kHz (—20 dB) and
20 kHz (—20 dB) is less than 2 dB.
Conduct step 5 ''Record/Playback Head Azimuth Alignment'.
If above is not sufficient, refer to ''Playback Frequency Response Adjust-
ment" in item 6.2.
ou.
Fig. 6.3
6.
Playback Level
7.
Playback Frequency Response
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