Adjustment Procedures - Grundig R 23 DPL Serviceanleitung

R 23 DPL
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Adjustment Procedures

Test Equipment:
Test Generator, Stereo Coder, Oscilloscope, Digital Voltmeter, AF-Voltmeter, Distortion Meter
Note:
The frontend is a completely preadjusted module. The values of the tuning voltages are:
87.5MHz = typ. 1.6V min. 1.3V
108MHz = typ. 8.3V max. 9.5V
Adjustment
1. Demodulator FM, 98MHz
Test generator 98MHz to aerial socket;
= 1mV / 75Ω, ∆f = 22.5kHz.
U
RF
Digitalvoltmeter to testpoint G (+/- CW603).
2. Stereo Distortion FM, 98MHz
Stereocoder, left channel modulated, to aerial socket;
98MHz, ∆f = 40kHz, ±6kHz pilot.
Distortion meter to AF output, left channel.
3. Stereo Crosstalk FM, 98MHz
Stereocoder, left channel modulated, to aerial socket;
98MHz, ∆f = 40kHz, ±6kHz pilot.
AF voltmeter to AF output, right channel.
4. Station search FM, 98MHz
Stereocoder 98MHz to aerial socket;
= 15µV / 75Ω, ∆f = 40kHz, ±6kHz pilot.
U
RF
5. 19/38 kHz Filter FM
Test generator to aerial socket; FM, f
AF voltmeter to AF output.
GRUNDIG Service
Preperation
= 38kHz.
mod
Abgleichvorschriften / Adjustment Procedures
Adjustment Procedure
±
Adjust T601 C to typ. 0V
50mV.
Adjust FE602 A to K
(typ. 0.5%, max. 1%).
min
Control the right AF output with modulated right channel.
Adjust VR602 D to minimum.
Control the left AF output with modulated right channel.
With VR601 B adjust the search threshold (typ. U
≤ 20µV) so that the „TUNED" indication
15µV, max. U
RF
still illuminates on the display.
Adjust T603 E (left channel) and T604 F (right channel)
to minimum.
=
RF
2 - 2