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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
AM;
Sweep Generator 450kHz to AM Aerial Input;
Ue > 60dBµV;
Oscilloscope to Testpoint TP5, IC502(-19).
2. AM Oscillator
AM, 1620kHz;
Digital Voltmeter to Testpoint TP3.
3. AM Band Pass
AM;
Couple Signal Generator via Loop Antennas;
Ue > 50dBµV; f
Oscilloscope to Loudspeaker Output.
4. FM IF
FM, 98.0MHz
Signal Generator to FM Aerial Input;
Ue = 20dBµV; f
Distortion Meter to Loudspeaker Outputs.
5. 19kHz Filter
FM;
Signal Generator to FM Aerial Input;
Ue = 50dBµV; f
Oscilloscope to Loudspeaker Outputs.
CD
Test equipment: Digital Voltmeter
Adjustment
DC Offset
Mode CD;
Digital Voltmeter between TP9 and TP10.
Preparation
= 1kHz;
mod
= 1kHz; Deviation = 75kHz;
mod
= 19kHz;
mod
Preparation
2 - 2
Adjustment Procedure
Adjust with T503 for
Maximum.
±
Adjust with T501 for 8.0V
0.2V.
Adjust alternating with L502 at 558kHz and with VC501 at
1440kHz for AF Maximum.
Adjust with IF Filter A (under the cover) for Distortion
Minimum.
Adjust with LPF501 (left channel) and with LPF502 (right
channel) for AF Minimum.
Adjustment Procedure
±
Adjust with VR701 for 0V
0.1V.
CIRFLEXX UMS 4201 SPCD
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