GRUNDIG BETA5DOTMATRIX
Manual de Servicio

Abgleichvorschriften / Adjustment Procedures

BETA 5

Adjustment Procedures
1. Main Board
Test equipment: DC Voltmeter, Test Generator, AF Voltmeter, Sweep Generator, Oscilloscope

Adjustment 1. MW Oscillator

Preparation MW; Connect a DC Voltmeter to FMP604. Connect a Test Generator to aerial input; fmod = 1kHz; E´ � 10µV (20dBµV). Connect an AF Voltmeter to Loudspeaker Output. Connect a Test Generator to aerial input; f = 1008kHz; fmod = 1kHz; E´ � 10µV (20dBµV). Connect an AF Voltmeter to Loudspeaker Output. FM; Connect a DC Voltmeter to FMP07.

Adjustment Procedure Align with L612 (1) at 531kHz for 1.2V ± 50mV. Check for 7.6V ± 0.6V at 1602kHz. Align alternating with L603 (3) at 558kHz and with C606 (4) at 1548kHz for maximum AF voltage.

2. MW Bandpass

3. AM IF

Align with F601 (9) for maximum AF voltage.

4. FM Oscillator

Align with L04 (A) at 93MHz for 2.6V ± 50mV. Check for 5.5V ± 0.5V at 108MHz.

5. Stop Generator

Connect a sweep generator to aerial input. Center fre- Align F 105 (I) for a symmetrical stop impulse. quency 93.0MHz; �f = ± 100kHz; no modulation; E´ = 1mV 93.0MHz (60dBµV); +5V Connect an Oscilloscope to FMP107. 0V �f � ± 28kHz Connect a Test Generator to aerial input; Frequency Align alternating with L01 (D) and L03 (C) for maximum AF 93.0MHz; fmod = 1kHz; Dev. = 22.5kHz; E´ = 3µV voltage. (10dBµV). Connect an AF Voltmeter to Loudspeaker Output. Align with F101 (F) for maximum AF voltage. Connect a Test Generator to aerial input; Frequency 95.0MHz; no modulation; E´ = 100µV (40dBµV). Connect a DC Voltmeter between FMP102 (+) and FMP109 (-). Adjust with R105 (H) for +300mV ± 20mV.

6. FM RF and IF

7. Field strength

2. Tape Drive
Test equipment: Frequency counter, Test Cassette 448A (Part No. 35079 023 0000)

Adjustment Tape Speed

Preparation Insert Test Cassette 448A and play 3150Hz part. Connect a frequency counter to loudspeaker outputs.

Adjustment Procedure With the ´Motorpoti´ adjust for 3150Hz ± 100Hz.

Motorpoti

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