Einstellvorschriften / Adjustment Procedures RR 710 CD / RR 750 CD
2 - 5 GRUNDIG Service
3. Tuner
Measuring instruments: Signal Generator, Sweep Generator, Oscilloscope, Digital Voltmeter.
Function switch: Radio
Alignment scheme see page 2 - 3.
Adjustment Preparations Adjustment Process
Adjust T302 to maximum.
At 1620kHz adjust to (VT) 7.5 ± 0.2V with T303.
Repeat the adjustment para 2 and para 4.
At 522kHz check (VT) 1.1 ± 0.3V.
At 558kHz
adjust to maximum with MW antenna coil
(move).
At 1440kHz
adjust to maximum with TC302.
Repeat this adjustment.
At 285kHz adjust to (VT) 7.5 ± 0.2V with TC304.
Repeat the adjustment para 2 and para 4.
At 150kHz check (VT) 0.8 ± 0.3V.
At 160kHz
adjust to maximum with LW antenna coil
(move).
At 280kHz
adjust to maximum with TC303.
Repeat this adjustment.
Adjust T301 to maximum.
At 108MHz adjust to (VT) 6V ± 0.3V with L303.
At 87.5Hz check (VT) 1.3 ± 0.5V.
At 88MHz
adjust to maximum with L302 (bend).
At 106MHz
adjust to maximum with TC301.
Repeat this adjustment.
Couple in a sweep signal of 455kHz to ferrite aerial via
a loop aerial.
Oscilloscope to testpoint TP4 (IC302 Pin6).
Band switch: MW
MW 1620kHz
Digital voltmeter testpoint TP5 (VT).
Band switch: MW
MW 558kHz, MW 1440kHz
Couple in a standard signal to ferrite aerial via a loop
aerial, (f
mod
= 1kHz, m = 30%, Ua <).
Oscilloscope to the headphone socket.
Band switch: MW
LW 285kHz
Digital voltmeter testpoint TP5 (VT).
Band switch: LW
LW 160kHz, LW 280kHz
Couple in a standard signal at to ferrite aerial via a loop
aerial, (f
mod
= 1kHz, m = 30%, Ua <).
Oscilloscope to the headphone socket.
Band switch: LW
Feed in a 10.7MHz sweep signal via 4pF to testpoint TP2
(IC301, Pin4).
Oscilloscope to testpoint TP3 (IC302, Pin9).
Band switch: FM
FM 108MHz
Digital voltmeter testpoint TP5 (VT).
Band switch: FM
FM 88MHz, FM 106MHz
Couple in the standard signal to TP1 (FM ant.),
(f
mod
= 1kHz, ∆f = 40kHz, Ua <).
Oscilloscope to the headphone socket.
Band switch: FM
1. AM IF
2. MW Oscillator
3. MW Aerial
bandpass
4. LW Oscillator
5. LW Aerial
bandpass
6. FM IF
7. FM Oscillator
8. FM Aerial
bandpass
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