Grundig Musik Boy 50 L RP Service Manual

Page 2

NOTE : USING SONY IC CXA1191 WITHOUT FM IFT

INSTRUMENTS REQUIRED

. Signal Generator

. FM Signal Generator

. FM/AM IF Sweep Generator(10.7 MHz for FM)
VTVM

. Oscilloscope

. Frequency counter

. Regulated DC power supply

ummpmN-x

AM IF ALIGNMENT

ALIGNMENT

MODEL NO.: GRUNDIG RP5240LW

GENERAL PREPARATION

. Check source voltage, DC or AC according to specificaions
. Set function switch to band being aligned

waA

. Standard modulation :

PROCEDURE

. Signal input should be kept as low as possible to avoid AGC and AFC function

AM 1 KHZ 30% mod
FM 1 KHz 22.5 KHz dev

STEP S'GNAL 50 (A153 RF 59"" CONNECT SET SIGNAL To ALIGNMENT INDICATOR (Oscilloscope, VTVM) CONNECT To SET $30 9' ADJUST ADJUST FOR REMARKS
TP 4 Volume control at
1 A standard radiation 460KHZ Detector output terminal Quiet Maximum min. position
loop and TP 2 ground Point T 2
2 Repeat step 1 for max. output

FM IF ALIGNMENT

This model requires no FM IF alignment as the IF is fixed by ceramic filter and discriminator CF 1 & CF 2. Please take note that correct type and same color dot of ceramic filter is used
in servicing, diff color dot of ceramic filter may cause worse IF '8' curve characteristic and distortion.

Connect IF genescope output terminal to TP 3 8. TP 2 (GND) in series with a 100 Pf capacitor. connect scope input terminal to TP 4 & TP 2 (GND), then the IF characteristic curve can be

observed.

GRUDDKE

Musik Boy 50L RP 5240 LW