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Einstellvorschriften / Adjustment Procedures
Adjustment Procedures
Measuring instruments/equipment:
Frequency counter, AF voltmeter, DC voltmeter, AF generator, distortion analyzer, wow and flutter meter,
Cr test cassette 448 A (part no. 35079-023.00), torque test cassette 456 (part no. 35079-014.00).
Layout of adjustment controls see page 2 - 3. Adjustment of the tape transport see page 2 - 6. The symbol
Adjustment
1. Tape speed
Frequency counter to LINE OUT.
Deck A/B
Insert test cassette 448 A in Deck A and Deck B respectively,
play back 3150Hz.
1. High Speed adjustment:
- Playback on Deck A and Deck B respectively.
- Short-circuit base + emitter of transistor T523.
2. Normal Speed adjustment:
Playback on Deck A and Deck B respectively.
2. Take-up torque
Load the torque test cassette 456 (Deck A/B).
on Start
Function: Start
Deck A/B
3. Wow and flutter
Wow and flutter meter to LINE OUT.
Deck A/B
Load test cassette 448 A (Deck A/B).
Play back 3150Hz
4. Head gap angle
Connect AF-voltmeter to LINE OUT L (left channel) and to
(Azimuth)
LINE OUT R (right channel) respectively.
Deck A/B
Load test cassette 448 A (Deck A and Deck B respectively),
play back 10kHz.
1
5. Playback level
AF-voltmeter to test point
Reference tape
(right channel).
scanning
Insert test cassette 448 A (Deck A and Deck B respectively).
(Dolby level)
Play back 315Hz (250nWb/m).
Deck A/B
Dolby off
Adjust Deck B first.
6. Erase frequency
Frequency counter to
Deck B
Insert a recordable cassette, Cr tape (IEC II).
Function: Record-Start
7. Erase current
AF-voltmeter to
Deck B
Insert a recordable cassette with Cr tape (IEC II).
Function: Record-Start
8. HX-PRO
DC-voltmeter to Pin13 IC105 (right channel) and to Pin6
Deck B
IC105 (left channel) respectively.
Insert a recordable cassette Cr tape (IEC II) in Deck B.
Function: Record-Start, Dolby off
9. Record blocking
AF-voltmeter to test point
point
circuits
(bias filter)
Insert a blank cassette in Deck A.
Insert a recordable cassette Cr tape (IEC II) in Deck B.
Function: High Dubbing
AF-voltmeter to test point
point
Function: High Dubbing
2 - 4
Preparations
PB-head Deck A
R/PB-head Deck B
2
1
D1 (left channel) or
L1 (R253).
TP (in parallel with R253).
D1 (left channel) and to test
D2 (right channel) respectively.
D3 (left channel) and to test
D4 (right channel) respectively.
Adjustment Procedure
1. High Speed adjustment: With adjustment control R566
(Deck A) or R561 (Deck B) set the frequency to 6300Hz
±
0.1% .
2. Normal Speed adjustment: With adjustment control
R564 (Deck A) or R558 (Deck B) set the frequency to
±
3150Hz
0.1%.
On START, the torque should be 25 to 70 x 10
≈ 40g-cm.
Deviation < 0.13% (IEC wtd). Playback measuring time
≥ 30 seconds.
Deck A+B
Tape direction: "Normal"
With the head adjustment screw 1 set the left or right
channel to maximum level.
Then connect the left channel in parallel with the right
channel (LINE OUT). By minimum re-adjustment of the
head adjustment screw 1 set the output level to maximum.
Turn around the test cassette.
Tape direction: "Reverse"
Adjustment with head adjustment screw 2 is the same as
in the "Normal" tape direction.
2
D2
Deck B:
With R156 (left), R157 (right) for Deck B and with R154
(left), R155 (right) for Deck A set a playback level of
±
0.5dB (LINE OUT ≈ 950mV).
490mV
When using a test cassette with 200nWb/m set the playback
±
0.5dB (LINE OUT ≈ 750mV).
level to 388mV
The oscillator frequency should be 85kHz
Adjust with L103.
Erase current: 150mA ± 10%
measured at R253 = 150mV ± 10%.
Adjust for minimum DC voltage with L104 at pin13 IC105
(right channel) and with L105 at pin 6 IC105 (left channel).
Adjust for minimum RF with F200 at test point
channel) and F210 at test point
Adjust for minimum RF with F106 at test point
channel) and F105 at test point
CCF 23
refers to a point in the circuit diagram.
-4
Nm
±
10kHz .
D1 (left
D2 (right channel).
D3 (left
D4 (right channel).
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