Nikko-Fam450-tun-sm 维修电路原理图.pdf

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1、RadioFans.CN 收音机爱 好者资料库(.,CONTENTS1. SPECIFICATION I.2. EXTERNAL VIEW 2.3. INTERNAL VIEW 3.4. PARTIAL DISASSEMBLY. 3-5.5. DIAL MECHANISM . . 5.6. MEASUREMENT AND ADJUSTMENT 6-A,7. PRINTED CIRCUIT BOARDftE8.9.10.TUNER PCBASSY 9.BLOCK DIAGRAM IO.OVERALL DIAGRAM I I.PARTIAL CHANGES MADEACCORDINGDESTINA

2、TION. 12.PARTS LIST. t3-* t5.SEM ICONDUCTOR SPECI FICATIONTRANSISTOR COMPLEMENT. . 16.FIELD EFFECT TRANSISTOR COMPLEMENT . . 16.RECTIFIER-DIODE, ZENER-DIODECOMPLEMENT. . I6.INTEGRATEDCIRCUITCoMPLEMENT. .17_19.11.12.!-.t-LrLRadioFans.CN 收音机爱 好者资料库SPECIFICATION1. FM TUNER SECTIONSensitivityOuiting Slo

3、peSelectivitylmage RejectionlF RejectionSignal to Noise RatioCapture RatioMuting SensitivityDistortionDistortionStereo SeparationOutput VoltageDe-Emphasis2. AM TUNER SECTIONSensitivitySelectivitylmage RejectionlF RejectionDistortionSignal to Noise RatioOutput Voltage(IHF)(s/N 50dB)(lHF)(98MHz)(98MHz

4、)(lHF)(MONO)(STEREO)(1KHz)(SOpSec) 10KHz(tHF)(lHF)110KHz . . .(1000KH2)(1000KH2)!2dBNOMINAL2ttY4.51tY55dB45dB70dB65dB1.6dB12dBo.20/oO.5o/o42dB690mV-10.37dB300pV/m35dB45dB35dB17o45dB135mVLIMIT3pV1OpV35dB40dB60dB60dB3dBrSdBO.5o/o1o/o3sdBr3dBc1000prV/m30dB40dB30dB2Vo40dB12dBEXTERNAL VIEWFRONT PANELIvv(

5、1) Signal/Tuning meter(2) Dial pointer(3) Stereo indicator(4) Power switch(5) Tuning knob .(6) Hi-blend switch(7) FM muting switch(8) Selector switchREAR PANELIJ(1)(2t(3)(4)(5)Coaxial cahle holder (GND)7 5 ohm FM antenna terminal300 ohm FM antenna terminalGround terminalAM antenna terminal(6) AM bar

6、 antenna(7) AC supply cord(8) AC 22Ol24O selector switch(9) Output r-INTERNAL VIEWTOP VIEWSelector switchFly wheelPower switchTuner PCB assy boardPower transformerAC cordAM bar antennaAntenna terminalst_(1)(2t(3)(4t(5)(6)(71(8)(1)(2t(3)(41(5)BOTTOM VI EWPower switchSignal/Tuning meterFly wheelTuner

7、PCB assy boardAM bar antennacJPARTIAL DISASSEMBLYCABINET REMOVALPHoro-l PHOTO_2Stand the cabinet up and remove screws (1-4) as shown in Photo-1.Return the cabinet to its original position and pull forward and then lift upto remove it (Photo-2).BOTTOM PLATE REMOVALTurn the cabinet and remove screws (

8、1-9) as shown inPhoto-3.rPHOTO_1PHOTO-,YJ.ll.-vzFRONT PANEL REMOVALPHOTO-4Remove screws (1-2) and nut (3) as shown in Photo 4-5.TUNER PCB ASSY BOARD REMOVALPHOTO_6Remove screws (1-8) as shown in Photo 6 then lift thecircuit board up to remove it.SWITCH PCB ASSY REMOVALRemove screws (1-2)forward to r

9、emove it.PHOTO-8as shown in Photo 8 and pullPHOTO_5POWER TRANSFORMER REMOVALPHOTO-7Remove screws (1-2) as shown in Photo 7 then lift thetransformer up to remove it.FLY WHEEL REMOVALPHOTO-9Remove screws (1-4) as shown in Photo 9 and pullforward to remove it.rIIPOWER SWITCH REMOVALPHOTO-10Remove screw

10、s (1-21 as shown in Photo 10 and pullforward to remove it.DIAL MECHANISMMETER REMOVALPHOTO-1 1Remove screws (1-4) as shown Photo 11 and pullforward to remove it.ItvJ5I.,Lr-UMEASUREMENT AND ADJUSTMENTSet the tuning dial pointer to zero(0) position on the dial panel. lf the dial pointer fails to coinc

11、ide with the zero(0) position at the left end of the knob rotation, have it reset to zero(O)Q! oosition by sliding on the dial string and then proceed as follows.FM SECTION1. FREOUENCY COVERAGE AND TRACKING ADJUSTMENTFor connecting, reler to Fig. 1.For adjusting point. refer to Fig. 2.StepGenerator

12、and Dial Freq.Adjustlndication and Remarks188 MHzL104Oscillator coil coreAdjust for max. reading2108 MHzc111Oscillator TrimmerAdjust for max. reading388 MHzL101ANT coil core, RF coil core4108 MHzFM1Adjust for max. reading588 MHzL102ANT coil core, RF coil coreb108 MHzFM2Adjust for max. reading7Repeat

13、 step 1, 2,3, 4,5, 6 Align after complete tuningSTANDARD DUMMY ANTENNAFAM-450TO FM ANTENNTERMINALSOSCILLOSCOPElo oll-zfi, IL,rrraar-lLtlllrlrrllL,rr rralrrra-I llatltllrtr I ltttrlatrtttfl I I lttrlrrfl Ie lttlltrltrl Io 4ttgtltult Iol_ !17 _ito (9l- =:- -a-il C o a;aa_.OOeoOOFFoooc- _e-_c . cE -r#;

14、* tt oo eSTANDARD SIGNAL GENERATORFig. 1Shield cableDISTORTION METERtaa)2.Fig.2FM-IF STAGE ADJUSTMENTFor adjustment of the discriminator coil T2O1 , connect the testing instruments as shown in Fig. 1 and then proceedas follows:(1) With no RF signal applied to the receiver, adjust the lower core of T

15、201 until the pointer of the tuning meter onthe receiver indicates the center position of the meter scale.(2) Apply RF signal to the receiver and adjust the tuning knob so that the tuning meter indicates the center posi-tion.(3) Under this condition, adjust the upper core of r2o1 for minimum distort

16、ion.(4) Repeat the above steps (1)through (3) two or three times so that the distortion factor is most improved.Note: For adjusting point, refer to Fig. 2.FM SEPARATION ADJUSTMENTwith stereo-modulated RF signal applied to the receiver, make adjustment as follows:(1) Turn the semi-fixed resistor R415

17、 (150K ohm) fully clockwise.(2) Connect a frequency counter to the test point #1 5 on the Tuner PCB Assy Board. Adjust the semi-fixed resistorR405 (10K ohm) for the frequency of 19 KHz t 19 Hz.(3) Adjust the semi-f ixed resistor R415 (150K ohm) for maximum stereo separation.Note: For adjusting point

18、. refer to Fig. 2.3.t)olII17.II-Ftu-AM2 FM2 AMl FMAM SECTION1. FREOUENCV COVERAGE AND TRACKING ADJUSTMENTThe following is intended to described the procedure of adjusting the AM section of the receiver using a sweepgenerator.ln the adjustment, the output voltage is applied through inductive coupling

19、.For adjustment. place a loop antenna near the receiver under test and ovserve the waveform of detector output(at the point lf22 on the Tuner PCB Assy Board)displayed on the alignment oscilloscope.For adjustment point, refer to Fig. 2.The waveform disprayed on the arigment oscilloscope is as shown i

20、n Fig. Fig.3.StepGenerator and Dial Freq.Adjustlndication and Remarks152O KHzT301Oscillator coil core adjust formaximum reading21650 KHzAM2Oscillator trimmer adjust formaximum reading3600 KHzAM BAR ANT.Antenna coil adjust formaximum reading41400 KHzAMlAntenna trimmer adjust formaximum readinq5Repeat

21、 steps 1-4 to obtain best tracking2. AM-IF STA.GE ADJUSTMENTThis adjustment is similar to the frequency coverage and tracking adjustment. Switch the sweep generator from RFto lF and follow the procedure below.The adjusting procedure is as follows:(1) With the receiver set to a high receiving frequen

22、cy (variable capacitor in full open position), adjust T302 andT303 until the lF waveforem becomes maximum.(21 lf , in this case, the adjustment is difficult because of disturbing sighal,facilitate the adjustment.(3) The waveform displayed on the aligment oscilloscope is as shown in Fig. 4. For adjus

23、ting posint, refer to Fig. 2.the variable capacitor may be turned to520KHZMARKER SIGNAL1,650KH2MARKERSIGNAL600KHZ 1400KHZMABKER MARKERSIGNAL SIGNALFis. 3FBLOCK DIAGRAM MODEL FAM.4sOEXT. AM ANT.FRONT ENDCERAMIC FILTERcF101 CF103EXT. AM ANT.AM TUNERSELECTOFSWITCHAM BAR ANT.AC LINEPOWER TRANSFORMER.f,-

24、 (,Dtsc colL0ani SIG./TUNING METEROUT PUTPOWER SUPPLYlLI.rit#LT STAB.IItiii1t-.:,iiFM IF AMP.1BHI.BLEND SWOVERALL DIAGRAM MODPCaorol 28K4911031027-tlircl04 7Pf,POR 10117RF COILLl0210t8ur.ArArcEl-rq - - II sooq I|-_BALANCE I-JldLl 05cF1 01,CFt 03SFE O.7MA83.3KR 1032.2t,H. irbi 68,R4O1 22Kr- _T_ lcBN4

25、K cl .!AM AilT coII LIc30a .o1l+4t-#doPOWER SWwHrBLXWHTYELWL3ilflffiilbr+ llloFilE,:t.;.cl.oo47DC5KV)qGac 120vl,L-t-L-r YEtPTr-r -253fd 6A. CANADAac 220vie-/ eloa 1i 9: L1o4c2SC44o4rc 301 HAI t 9?C9O3 22OM,/16O9O1 2SO23S= not-loIloIloI9xtol_:_l;-tIIs4 Y Y mD,Iltcl .o1 Ac125v IjF3 1ADIAGRAM MODEL FAM

26、-45OR2O5 12KT1031027rll-Jl dcFl 01,CF1 03SFE 1 O,7MA8L105 2.2ilXs2ooNffiJ,_ llurlleotr olqr|, dJIlLIl717$El.itho_ ji_ I r.oorsc423BF3O2t3axHz)o2DE-EMPHASISt5,o.oorzlft)50,.680PL-l YEIPTT 1-253td SA CANADAoPl:ocoiGFtotol8ntfl aF3orc41-6-.OO1 (38KHz)F415 tsoK(a) R4OA 6.ar33x I - ncrc lnlto 1rK c11o1ou

27、/16: I L : lr.1 - jriu*u*: =ef rr+J-s t.+ + + c422 +l fc415 0o1 0 cltz-.oor lll-rffiFf i6lnnnn.R41?.4.3K lnrrsr.rrl 1l . ltRa23- rx-toEJ.-ol-*t-tISIGtrAL/TUtrI TG M ETITypeClass ot ServiceMaximum Ratings (TA=25oC)Electrical Characteristics Typical Valuel TA=2socPowerSupply(v)PowerDissiptationPd.(MWI

28、OperatingTemp. RangeToptctStorageTemp. RangeTstgcSignal to NoiseRatioI nput=74dBpMod.=30%(dB)Distortionlnput=74d8,Mod.=30%t%)DetectorOutputI nput=74dBpMod.=30%(mV)AGC. FOMI nput:loodBrr=odBConsumptionVcc=1 2VlmA)ManulactureHAl 197AIV RADIO15450-20-+70-55-+125530.42127514.5HITACHII NTEGATED CI RCUIT

29、COMPLEMENT SPECI FICATIONCONNECTION DIAGRAM (TOP VIEWSCHEMATIC DIAGRAMl)oGUINTEGRATED CIRCUIT COMPLEMENTGoNNECTTON DTAGRAM (TOP VIEW)-(tMtrimum fl6rino Ta=25CElocrrical Ch.acrsisaica (Typicrl v.l) Ta = 25cOi3sipaionOtsratingcStor.gtT3tgrc)Limntinot*)Signri rod8)daHAI l37WFM.IFOuaJhrur-D.l.clorl4550t

30、9-20- +80-55- + I 2532l5-3dB oohtl3molMrN.5745HITACHISCHEMATIC DIAGRAMi,.-U-INTEGRATED CI RCU IT COMPLEMENT SPECI F ICATIONCONNECTION DIAGRAM (TOP VIEW)INDEXSCHEMATIC DIAGRAM,; -.:-.v/-aIIIIttt:bgr IIIIIIrypeClass of SeruiceMaximum Ratings (TA=25C)Electrical Characteristics Tvpical Value) TA=25oCMan

31、ufactureSupplyv)PowerDissipationPd.(mwlLampDriverl1(mA)OperatingTemp. RangeTopt(c)StorageTemp. RangeTstg(c)lnputlmpedanceZin(KC,)StereoSeparationdB)ChannelBalance(dB)Distortion(stereo)l/.tLampLevelmV)OutputVoltagelnput=2-mV (mV)HA1 196FM STEREODEMODULATOR15490-20 - +70-55 - +1257550(at 1 KHz)tl.50.1(at 1 KHz)MtN 4.O1.2VH ITACH Ir9.I-J