Grundig-Sonoclock-755-Schematic电路原理图.pdf

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1、nderungen vorbehaltenSubject to alterationsonoclock 755Es gelten die Vorschriften und Sicherheitshinweise gem dem Service Manual “Sicherheit“, Sach-Nummer 72010-800.00, sowie zustzlich die eventuell abweichenden, landesspezifischen Vorschriften!The regulations and safety instructions shall be valid

2、as provided by the “Safety“ Service Manual, part number 72010-800.00, as well as the respective national deviations!72011 049 5200 (0498)Druckplattenabbildungen / Illustration of Printed BoardsBestckungsseite / Component sidenderungen vorbehaltenSubject to alterationsonoclock 75572011 049 5200 (0498

3、)sonoclock 755VerdrahtungsplanWiring Diagramnderungen vorbehaltenSubject to alteration72011 049 5200 (0498)FM RF ALIGNMENTSTEPSIGNAL SOURCE (FM Signal Gen.) CONNECT TOSET SIGNAL TOALIGNMENT INDICATOR (Oscilloscope, VTVM) CONNECT TOSET RADIO DIAL TOADJUSTADJUST FORREMARKSL104 (Osc. coil)1 87.35 MHz (

4、Lowest end) stretch or(modulated) squeezeTP ( 1 ) & ( 2 ) 108.25 MHz Terminals VCT1 B Volume2 through matching network (modulated) across speaker (Highest end) (Osc. trimmer) Maximum control atif necessary voice coil L103 (RF coil) max. position3 88 MHz 88 MHz stretch or(modulated) squeeze106 MHz VC

5、T1 A4 (modulated) 106 MHz (RF trimmer)5 Repeat steps 3 and 4 as necessary to minimize tracking error and also steps 1 and 2 if necessaryAM RF ALIGNMENTSTEPSIGNAL SOURCE (AM Signal Gen.) CONNECT TOSET SIGNAL TOALIGNMENT INDICATOR (Oscilloscope, VTVM) CONNECT TOSET RADIO DIAL TOADJUSTADJUST FORREMARKS

6、515 KHz L1051 (modulated) (Lowest end) (Osc. coil)1630 KHz VCT1 C Volume2 A standard radiation (modulated) Across speaker (Highest end) (Osc. trimmer) Maximum control atloop ant. 588 KHz voice coil L102 max. position3 (modulated) 558 KHz (ant. coil)1440 KHz VCT1 D4 (modulated) 1440 KHz (ant. trimmer

7、)5 Repeat steps 3 and 4 as necessary to minimize tracking error and also steps 1 and 2 if necessaryCLOCK FREQUENCY ALIGNMENTSIGNAL SOURCE CONNECT TOSET SIGNAL TOALIGNMENT INDICATOR (Frequency Counter) CONNECT TOSET RADIO DIAL TOADJUST ADJUST FOR REMARKSNo signal TP ( 5 ) and TP ( 6 ) with 10 : 1 tes

8、t probe Through Any 4.194304a cap. 1 pF to 3 pF. ( It depends on the sensitivity of Point Trimmer 200 Mhzthe frequency counter )A L I G N M E N T P R O C E D U R E MODEL NO. : SC-755INSTRUMENTS REQUIRED GENERAL PREPARATION1. Signal Generator 1. Check source voltage, DC or AC according to specificati

9、ons2. FM Signal Generator 2. Set function switch to band being aligned3. Sweep Generator (10.7 MHz for FM) 3. Signal input should be kept as low as possible to avoid AGC and AFC function4. VTVM 4. Standard modulation : AM 1 KHz 30% mod5. Oscilloscope FM 1 KHz 22.5 KHz dev6. Frequency counter7. Regul

10、ated DC power supplyAM IF ALIGNMENTSTEPSIGNAL SOURCE (AM RF Gen.) CONNECT TOSET SIGNAL TOALIGNMENT INDICATOR (Oscilloscope, VTVM) CONNECT TO SET RADIO DIAL TOADJUST ADJUST FOR REMARKSA standard radiation TP ( 4 ) Detector output terminal Quiet Volume control at1 loop 465 KHz and ground Point T102 Ma

11、ximum min. position2 Repeat step 1 for max. outputFM IF ALIGNMENTThis model requires no FM IF alignment as the IF is fixed by ceramic filter and discriminator CF1 & CF2. 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 S curve characteristic and distortion.Connect IF genescope output terminal to TP3 & TP2 (GND), connect scope input terminal to TP4 & TP2 (GND), then the IF characteristic curve can be observed.nderungen vorbehaltenSubject to alteration72011 049 5200 (0498)