Adjustment Procedures - Grundig M 100-CF Serviceanleitung

M 100-CF

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 1 - 9.
Adjustment
1. Tape speed Frequency counter to LINE OUT.
Insert test cassette 448 A.
Play back 3150Hz.
2. Take-up torque Load the torque test cassette 456.
on Start Function: Start.
3. Wow and flutter Wow and flutter meter to LINE OUT.
Load test cassette 448 A.
Play back 3150Hz.
4. Head gap angle Connect AF-voltmeter to LINE OUT L (left channel) or to
(Azimuth) LINE OUT R (right channel).
Load test cassette 448 A, play back 10kHz.
E
5. Playback level AF-voltmeter to test point
Reference tape (right channel).
scanning Insert test cassette 448 A.
(Dolby level) Play back 315Hz (250nWb/m).
Dolby off.
6. Erase frequency
Frequency counter to test point
Insert a recordable cassette with ME tape (IEC IV).
Function: Record-Start.
7. Erase current AF-voltmeter to test point
Insert a recordable cassette with ME tape (IEC IV).
Function: Record-Start.
8. HX-PRO
Connect the DC-voltmeter to Pin13 IC111 (left channel) or
to Pin6 IC111 (right channel).
Insert a recordable cassette with ME tape (IEC IV).
Function: Record-Start, Dolby off.
9. Record blocking
Connect the AF-voltmeter to test point
circuits
or to test point
(bias filter) board.
Insert a recordable cassette with ME tape (IEC IV).
Function: Record-Start, Level pot. minimum.
10. MPX-filter Connect the AF-generator (f
(19kHz stereo to the LINE IN sockets.
pilot tone)
Connect the AF-voltmeter to the
test points
or D2 (right channel).
Insert a recordable cassette with ME tape (IEC IV).
Function: Record-Start, Dolby off.
Dolby off.
GRUNDIG Service
Preparations
Tape run Tape run
"Normal" "Reverse"
D1 (left channel) or
L1 (R263).
L1 (in parallel with R263).
TP3 (left channel)
TP4 (right channel) on the audio circuit
= 315Hz, f = 19kHz, 500mV)
1 2
≈
D1 (left channel)
With adjustment control R482 (Logic board) set the
frequency to 3150Hz
On START, the torque should be 30 to 60 x 10
≈ 40g-cm.
≤
Deviation 0.1% (IEC wtd).
Playback measuring time ≥ 30 seconds.
Tape direction: "Normal"
With the head adjustment screw E 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 E set the output level to maximum.
Turn around the test cassette.
Tape direction: "Reverse"
F
Adjustment with head adjustment screw F is the same as
in the "Normal" tape direction.
D2 Set the playback level with the adjustment controls R135
(left) or R136 (right) to 490mV
(LINE OUT ≈ 950mV).
When using a test cassette with 200nWb/m set the play-
back level to 388mV
(LINE OUT ≈ 750mV).
The oscillator frequency should be 85kHz
Adjust with L111.
Erase current: 175mA ± 20% measured at R263
= 175mV ± 20%.
Adjust for minimum DC voltage with L113 at pin13 IC111
(left channel) and with L114 at pin6 IC111 (right channel).
Adjust for minimum RF with F111 at test point
channel) and F112 at test point
Set the level control (RECORD LEVEL) during Record so
that at 315Hz the voltage measured at the test points
10 k
D1 and D2 is V
≤
At 19kHz = V
10 k
o
LINE IN
Adjust with F101 (left channel) or F102 (right channel).
Einstellvorschriften / Adjustment Procedures
Adjustment Procedure
±
1.0%.
-4
Nm
±
0.5dB.
±
0.5dB.
±
10kHz.
TP4 (right channel).
= 388mV (= 0dB).
o
12mV (≤ –30dB).
TP3 (left
2 - 2 2 - 4