GRUNDIG UMS 4401 SPCD
Instrukcja Serwisowa

GRUNDIG Service

VARIXX UMS 4401 SPCD

Adjustment Procedures

Tuner
Test equipment: Signal Generator, Oscilloscope, Digital Voltmeter Adjustment 1. AM IF Preparation AM, 522kHz; Couple Signal Generator 450kHz via Loop Antenna; Ue > 60dBµV; Oscilloscope to Loudspeaker Output. AM, 1620kHz; Digital Voltmeter to Pin 8 of IC101. AM, 603kHz/1404kHz; Couple Signal Generator via Loop Antenna; Ue > 50dBµV; fmod = 1kHz; Oscilloscope to Loudspeaker Output. Adjustment Procedure Adjust with T105 and T104 for Maximum.

2. AM Oscillator

Adjust with T102 for 7.8V ± 0.2V.

3. AM Band Pass

Adjust alternating with T101 at 603kHz and with T108 at 1404kHz for AF Maximum.

4. AM-AFC

AM, 522kHz; Adjust with T106 for 0V ± 1mV. Couple Signal Generator 450kHz via Loop Antenna; Digital Voltmeter between Pin 19 and Pin 20 of IC101. FM, 87.5MHz; Adjust with T103 for 0V ± 1mV. Signal Generator to FM Aerial Input; Short circuit Pin 21 of U102 to GND; Digital Voltmeter between Pin 19 and Pin 20 of IC101. FM, 87.5MHz; Signal Generator to FM Aerial Input; fmod= 19kHz; Oscilloscope to Loudspeaker Output. Adjust with IFT181 (left channel) and IFT182 (right channel) to Minimum.

5. FM-Det.

6. 19kHz Notch Filter

Tape Deck
Test equipment: Oscilloscope, Frequency Counter, Test Cassette 3150Hz/10kHz (e.g. 448A) Adjustment 1. Tape Speed Preparation Frequency Counter to Loudspeaker Output. Play Test Cassette (3150Hz part). Adjustment Procedure Adjust Motorpoti for 3150Hz ± 10Hz.
Motorpoti

2. Azimuth

Oszilloscope to Loudspeaker Output. Play Test Cassette (10kHz part).

With Head screw A adjust for maximal and equal level in both channels.

A
3. Bias Frequency Frequency Counter to CN105-RR/LR. Start recording.
2-2

Adjust with T201 for 60kHz ± 100Hz.