Einstellvorschriften / Adjustment Procedures
RR 620 CD / RR 650 CD
2 - 5
GRUNDIG Service
3. Tuner
Measuring instruments: Signal Generator, Sweep Generator, Oscilloscope, Frequncy Counter.
Function switch: Radio
Alignment scheme see page 2 - 3.
Adjustment
Preparations
Adjustment Process
Adjust T302 to maximum.
At f
u
(526.5kHz) adjust to maximum with T305.
At f
o
(1606.5kHz) adjust to maximum with TC4.
Repeat this adjustment.
At 610kHz
adjust to maximum with MW antenna coil.
At 1400kHz
adjust to maximum with TC3.
Repeat this adjustment.
At f
u
(148.5kHz) adjust to maximum with T304.
At f
o
(283.5kHz) adjust to maximum with TC302.
Repeat this adjustment.
At 160kHz
adjust to maximum with LW antenna coil.
At 280kHz
adjust to maximum with TC301.
Repeat this adjustment.
With T301 and T303 adjust to maximum and symmetry.
At f
u
(87.5MHz) adjust to maximum with L303.
At f
o
(108MHz) adjust to maximum with TC1.
Repeat this adjustment.
At 90MHz
adjust to maximum with L302.
At 106MHz adjust to maximum with TC2.
Repeat this adjustment.
Set the frequency to 76kHz
±
100Hz with VR301.
Couple in a sweep signal of 465kHz to ferrite aerial via a
loop aerial.
Oscilloscope to the headphone socket.
Band switch: MW
Var. capacitor to limit stop: MW f
u
526.5kHz, f
o
1606.5kHz
Couple in a standard signal to ferrite aerial via a loop
aerial, (f
mod
= 1kHz, m = 30%).
Oscilloscope to the headphone socket.
Band switch: MW
MW 610kHz, MW 1400kHz
Couple in a standard signal to ferrite aerial via a loop
aerial, (f
mod
= 1kHz, m = 30%).
Oscilloscope to the headphone socket.
Band switch: MW
Var. capacitor to limit stop: LW f
u
148.5kHz, f
o
283.5kHz
Couple in a standard signal to ferrite aerial via a loop
aerial, (f
mod
= 1kHz, m = 30%).
Oscilloscope to the headphone socket.
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%).
Oscilloscope to the headphone socket.
Band switch: LW
Feed in a 10.7MHz sweep signal to TP3 (FM ant.).
Oscilloscope to TP2 (IC302, Pin9).
Band switch: FM
Var. capacitor to limit stop: FM f
u
87.5MHz, f
o
108MHz
Couple in a standard signal to TP3 (FM ant.),
(f
mod
= 1kHz,
∆
f = 22.5kHz).
Oscilloscope to the headphone socket.
Band switch: FM
FM 90MHz, FM 106MHz
Couple in the standard signal to TP3 (FM ant.),
(f
mod
= 1kHz,
∆
f = 22.5kHz).
Oscilloscope to the headphone socket.
Band switch: FM
Couple in a standard signal of 98MHz, unmodulated to
TP3 (FM ant.).
Frequency counter to TP5.
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
9. FM MPX (Stereo)