Grundig KM 12, Руководство по обслуживанию, Страница: 15 / 32

GRUNDIG Service 2 - 2
Abgleichvorschriften / Adjustment Procedures KM 12
GB
Adjustment Procedures
1. Tuner
Test equipment: Test Generator, Stereo Coder, Oscilloscope, DC Voltmeter, AF Voltmeter
2. Cassette Part
Test equipment: AF Voltmeter, Frequency Counter, Test Cassette 449 Part No.: 35079-019.00
Adjustment Preperation Adjustment Procedure
1. Azimuth
2. Tape Speed
Adjust screw
A
for AF maximum.
Adjust SFR201 for 3110Hz - 3240Hz.
Access to the screws is gained through holes below the
cassette flaps.
Play Test Cassette 449, 10kHz part.
AF voltmeter at AF output.
Tape, Fe.
Play Test Cassette 449, 3150Hz part.
Frequency counter at AF output.
Adjustment Preperation Adjustment Procedure
1. RF Gain
2. E-F-Balance
Adjust VR01 for 0V
±
20mV.
Set VR02 so that the signal amplitude is symmetrical
to the datum line (A=B).
Set CD player to STOP.
DC voltmeter at test point CN12.
Connect a diode (1N4148) between pin 19 (anode) and
pin 8 (cathode) of connector CN601 on the Front Panel
as shown on page 3 - 12, and solder the buttons
„CD CHECK“ and „REPEAT“ on to the panel.
Oscilloscope to test point CN02 (+/-).
Load the test CD and play.
Depress the soldered buttons „CD CHECK“ and
„REPEAT“ simultaneously and adjust VR02.
On completion of this adjustment press the „STOP“
button and remove the diode.
Adjustment Preperation Adjustment Procedure
1. AM IF
2. AM Oscillator
3. AM Aerial
Bandpass
4. FM Oscillator
5. FM Aerial
Bandpass
6. Stereo
MW; set the tuner to 522kHz.
Test generator 450kHz at aerial input.
U
a
as low as possible; f
mod
= 400Hz; m = 30%;
AF voltmeter at test point TP1(IF).
MW;
DC voltmeter at test point TP1(VT).
MW;
Test generator at aerial input.
U
a
as low as possible; f
mod
= 400Hz; m = 30%;
AF voltmeter at loudspeaker output.
FM;
DC voltmeter at test point TP1(VT).
FM;
Test generator at aerial input.
U
a
as low as possible; f
mod
= 400Hz;
∆
f = 22.5kHz;
AF voltmeter at loudspeaker output.
FM;
Stereo coder 98MHz at aerial input.
U
a
= 26dB
µ
V; f
mod
= 19kHz;
Adjust T102 for AF maximum.
Adjust L105 at 522kHz for 1.2V
±
0.05V.
Check at 1629kHz 8.0V
±
1.0V.
Adjust alternately L104 at 603kHz and TC102 at
1404kHz for AF maximum.
Adjust L103 at 87.5MHz for 1.2V.
Check at 108MHz 8.0V
±
1.0V.
Adjust alternately L102 at 90.0MHz and TC101 at
106.0MHz for AF maximum.
With SFR101 adjust the stereo threshold (U
a
= 26dB
µ
V)
so that the stereo indication still illuminates on the
display.
3. CD Part
Test equipment: DC Voltmeter, Oscilloscope, Test CD Part No.: 72008-376.00
A