GRUNDIG UMS4201SPCD
Instrukcja Serwisowa

GRUNDIG Service

CIRFLEXX UMS 4201 SPCD

Adjustment Procedures
Tuner
Test equipment: Sweep / Signal Generator, Distortion Meter, Oscilloscope, Digital Voltmeter Note: The frontend is a completely preadjusted module. Only the IF filter must be adjusted to the IF amplifier (Adjustment 4). The values of the tuning voltages are as follows: 87.5MHz = typ. 1,6V; 108MHz = typ. 8.0V.

Adjustment 1. AM IF

Preparation AM; Sweep Generator 450kHz to AM Aerial Input; Ue > 60dBµV; Oscilloscope to Testpoint TP5, IC502(-19).

Adjustment Procedure Adjust with T503 for Maximum.

2. AM Oscillator

AM, 1620kHz; Digital Voltmeter to Testpoint TP3. AM; Couple Signal Generator via Loop Antennas; Ue > 50dBµV; fmod = 1kHz; Oscilloscope to Loudspeaker Output. FM, 98.0MHz Signal Generator to FM Aerial Input; Ue = 20dBµV; fmod = 1kHz; Deviation = 75kHz; Distortion Meter to Loudspeaker Outputs. FM; Signal Generator to FM Aerial Input; Ue = 50dBµV; fmod = 19kHz; Oscilloscope to Loudspeaker Outputs.

Adjust with T501 for 8.0V ± 0.2V.

3. AM Band Pass

Adjust alternating with L502 at 558kHz and with VC501 at 1440kHz for AF Maximum.

4. FM IF

Adjust with IF Filter A (under the cover) for Distortion Minimum.

5. 19kHz Filter

Adjust with LPF501 (left channel) and with LPF502 (right channel) for AF Minimum.

CD
Test equipment: Digital Voltmeter

Adjustment DC Offset

Preparation Mode CD; Digital Voltmeter between TP9 and TP10.

Adjustment Procedure Adjust with VR701 for 0V ± 0.1V.

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