Pioneer-SX7-rec-sm维修电路原理图.pdf

cDrJroNEEr Shot/,n tn thb photo b Model SX-7. ORDER NO. ARP-047-O COMPUTER CONTROLLED STEREO RECEIVER sx-7 sx-6 SX-s.SiX-EiL SX-,QISX-4L . The AM tuner of SX-4L wave-band tuner with MW LW (long wave). and SX-SL is a two (medium wave) and Model SX-7 (and SX-6, SX-5 and SX-4) are new types of receivers featuring microcomputers for easier operation. The AM/FM tuner stages incorpo- rate quartz PLL synthesizers for high stability, while the power amplifier stage is a non-switching amplifier which achieves class A quality with class B efficiency (not included in the SX-4 model). PIoNEEF| ELECTFICINTC CCtFtFCtFtATtCtN 1 chome. Mesu.o ku. rokyo 153. J5p5n U.a. tfcritlaF alaC?Flo|llca CCFFC,;|AY|C|N a5 orro.d o. ve. Moonach e. New Je.sey O7O74, t)S A FlONaaE aL:ClFlC,lIC ll(rFCPC N.V. Lu thasen Haven I 2O3O A.we.p Bergum FroNaatl an.actFctNlca aua?FAl-ra ETY. LYo. 1 7a 1Ba Bound ro. s 31 95. aust.6r, F H O AUG.1981 Printed in lapan RadioFans.CN 收音机爱 好者资料库 BLOCK DIAGRAMS SX.4/KU FM FRONT ENO FM IF AMP A DETECTOR FM MPX STEREO OEMOOULATORFREQUENCY OISPLAY - toon Fx l- GNo ! IF AHP A DETECTOR IC ii#n i*- l TUNING OETECTOR IC P06004 R6 R7 voo R 8 R 9 ,o ffi R t l K O K I K 2 K 3 . I R Q PO bl PLL SYNTHESIZER CIRCUIT FT4,/AM SLECTOR 8CO TO OECIHAL OECOROER -4-r.:-: ItPx STEREo oEcooR Ic POWER AMPLIFIER AUX / vroEo R . C H REC T FlADAPToi PLAY FUXCTION SELECTOR i- X U T I N G CONTROL 3 9 . 6 d 8 A T r t H r + rr r*S* _.Qp-q oFF TAPE,/AOAPT SW I HOOE SW -O t moro or LOU0llESS sw : SPEAKERS t fr l pxoHes r-_+_zi I I f-)t * # l + - f l t - R.cx J lUN ER sEcrrofl Eq AXP FUIClOli SELECTOR 2 AC l2Ov 60Hr RadioFans.CN 收音机爱 好者资料库 SX-s/KU FH FROIIT EiTO FM IF AMP. A OETECTOR FREQUETCY OISPLAY MPX STEREO ocooER Ic LEO tUTERIC OISPLAY IF AMP A OETECTOR IC ,L- L-nn I l_t l_t .l_t l_t I oerscron I I stGrAL I METER I our TUNING OETECTOR IC P0500rr R t O R E S E T R r l KO r ( t K 2 K ! P I l R O PO d - _ - stAlto.BY O l o: o! HUTE PLL SYNTHESIZER CIRCUIT PHONO EO. AMP FMlAM SELECTOR 8CO TO OECIMAL /E Y9 YO YI Y2 Y3 Y4 T! lux / vr0o il POWER AMPLIFIER 4 l . 3 d B A T t t X r L CX. Ic rElrcrnor LIY FutcTrofi sLcToR r-*:* Pq OFF F steoxens P1o*tt f1-=J )r | -|J l.-_ rcx rO POWER SUPPLY CTRCUIT cotTRoL crlculT POWTR TRATSFORMER A C l z o v , 6 0 X t 3 AC OUiL EIS RadioFans.CN 收音机爱 好者资料库 SX-6/KU AM ANIENNA AM STEREO CONTROL CIRCUIT MEMORY I /sToP 1 rDowN l TUNING t u PRESET RF. OSC tTC40498P) ; soorHt + ttt th II t PRESEI ( STEP tNo. - 4 2 d 8 A T t t H r ) APE I l8trtk FUNCTION ( PA4008) it- ? t l d, d) ;1* o suSsoN rc ouT/ J LOUONESS ott o + 9 7 ? 6 J EALANCE -83 TAPE I r?) (3) (4 5t STATION IND LOCAL osc 1 I I t-l t-t t-t t- 1 t_t l_t.t_l t_l x tN x ouT (D OC 08 S 25tHr RESET 2 0 t 9 4 3 2 t 9 t 2 / l OISPLAY C IRCU IT 4 0 3 9 3 4 3 3 3 2 3 1 3 0 2 9 2 8 2 7 5 1 6 1 5 r 4 r 3 L lN J + tNlOUT - SO LOUTJ CONTROL (PD6OO4) E tN/ tN/ xiar_ n-ESer nO STANO By r oUT r rOUT - roUT- 4 37 9 tO il t2 252423 222Ot9 t8 t7 34 t 2 3 4 5 6 7 MUTE I L t N ( LC T I L T2_ PROTECTION CIRCUIT + 4 . 9 V ( + 8 7 ) +4.9V (+ 88) OVERLOAO OETECTOR F T O I *t.-.-*l RcH + + _ ! _ l t o R c H t ) HEAOPHONES L R L R A - S P E A X E R S - A 4 RadioFans.CN 收音机爱 好者资料库 N F uJ(L I o F rc ooo lrJ F (L = It t! q J o He lrJ a 6ts x8 ! lrJ o I (l P o UJ F trJ o 6 (L = t! $t-r_-r fr gl_r_-r t ?,:,:_-e gr-,:,d* i- E - F ll ci (l ro o z N F 9 gl EI el =l f - r t r :;: 6E E tr9 = *2 5 L ) () x o J L a o 9 (r lrj N U) trJ I F z (n J J o o-l iil l l o t r ) l =il ;el (9 z F f= r-r E - i l= sl alF 3l _ l z z l - - ( J l =- L lrJ o o z a F() lrJ F (l n (r lrl F lrJ (r lrl = I F f (L F l o c lrJ G o J o- I o o z trJ o lrl E l! I Z F GI tt ta, r.t t (, = F E ( h F N t u c r N ( r tE2,: ( r . < o c -t z 3 J dr E l F() z t 8 l1! ItE trl F l= = (h 9 E ?EE diES ( l ) i l ) u L ! =U;-fl F xgS 2 P F f(-) E () - L L l q (r LU = U tt o F I = J o E F c6 z(J 9r F = (J? 3d uJ a ./t ql = q 5 N - J ( n il E 6 o I39 : N R I c !n o Y Y o ( D r ! l . l U() z J CD l- o -l E, -t -l Et zFh ?,5 Cp ER l9E E.n = J r L = _ J E : i (l lrJ F s? a z- U J . c _ a ; HH F : o 5_8 o o Et E - l t - : o 5_8 o c -t N N U g IJ (L s Iu F = (n 9 z (r F o lrJ fr J o (r F z o (J J z (9 ( N I= F (D tt d ro ct E d rO o- o lrl o z o I (E lrj (9 (, c F F lrl an lrl (r o Y ! 4 5H = 5 b9 z t 3P g = N r o s l : r l u t c i , J s aElq =r I g t o N . to ? . 6 . . E ( ) N | r ) o = t r i e3 L* 6 RadioFans.CN 收音机爱 好者资料库 CIRCUIT DESCRIPTIONS Outline of Main Stage The overall composition is outlined in the block diagnms on pp.2-6. r Tuner Stage o AM/FM Synthesizer Stage *MANUAL : Frequency changed in single steps each time the TUNING UP or DOWN hey is pressed. Frequencies scanned when pressed continuously, the scanning being stopped as soon as the hey is released. *STATION SCAN : Frequencies scanned. when either TUNING UP or DOWN key is pressed. Scanning pauses for 5 seconds when a broad.casting station b tuned, and stops altogether if the MEMORY/STOP key is pressed within that 5 second period. Otherwise, the scanning is resumed., *STATION SEARCH : Frequencies scanned when either TUNING UP or DOWN key is pressed, and stopped when a broadcasting station is tuned. sx-7sx-6sx-5sx-4 l.D. MOS FET single-stage RF amplifier plus twin vari-cap tuning circuit (equivalent to 4-ganged tuning capacitor) in FM front-end. Same as SX-7 J-FET single-stage RF amplifier plus twin vari-cap tuning circuit (equivalent to 3anged tuning capacitor) in FM front-end. Same as SX-S PLL lC stereo decoder stage Same as SX-7Same as SX-7Same as SX-7 Vari-cap tuning circuit (equiva- lent to 2-ganged tuning capaci- torl in AM tuning stage and AM tuner lC lLA1247l. Same as SX-7Same as SX-7Same as SX-7 sx-7sx-6sx-5sx-4 lmproved S/N ratio achieved by pulse-swallow system for FM reception. S/N ratio 80dB(Mono) 75dB (Stereol Same as SX-7 S/N ratio 8od8(Monol 75dB(Stereo) Same as SX-7 S/N ratio 75dB(Mono) TOdB(Stereo) Same as SX-7 S/N ratio 75dB(Monol 70dB(Stereo) Frequency memory (presetting) capability for up to 8 stations in each band. Same as SX-7 Frequency memory (presettingl capability for up to 6 stations in each band. In models including two AM bands (LW and MW), any LW or MW frequencies may be stored in the 6 AM memories. Same as SX-5 3 tuning modes: MANUAL STATION SCAN STATION SEARCH Same as SX-72 tuning modes: MANUAL STATION SCAN only the sTATloN scAN tuning mode is available. RadioFans.CN 收音机爱 好者资料库 o Amplifier Stage o Display Stage sx-7sx-6sx-5 sx-4 Equalizer amplifier features low- noise twin FET ICL differential amplifier in first stage, and oper- ational amplifier (lC) in second stage for MC cartridges. S/N ratio 8OdB(MM) 67dB(MC) Equalizer amplifier features low- noise transistors differential amplifier in first stage. and oper- ational amplifier (lC) in second stage. S/N ratio 79dB Operational amplif ier (lC) euqalizer amplifier. S/N ratio 70dB Same as SX-S S/N ratio Microcomputer controlled elec- tronic switching lC (PA40O8l for function selector. Same as SX-7Same as SX-7Same as SX-7 Microcomputer controlled VCA lC(PA5O04) volume control features 32-step control, pre- settable levels and audio rnuting (-2sdBl. Same as SX-7 Conventional volume control with variable resistor. Same as SX-5 Non-switching amplifier em- ployed in power amplifier stage. Output power 60W+60W l2OHz-20kHzl Rated distortion O.009% Same as SX-7 Output power 45W+45W (20H2-20kHz) Rated distortion 0.OO9% Same as SX-7 Output power 30W+30W l2OHz-20kHzl Rated distortion O.O2/ Conventional class B ampli- f ier Output power 20W+2OW l2OHz-2Okzl Rated distortion O.O4% sx-7sx-6sx-5sx-4 s-digit LED numeric display of tuned frequency. Same as SX-7Same as SX-7 16-point scale LED display of tuned frequency. LED numeric display of elec- tronic volume control levels. Same as SX-7 Not featured in SX-5Not featured in SX-4 LED numeric display of time (built-in quartz clock function). Not featured in SX-6Not featured in SX-S Not featured in SX-4 6-point LED display of output power. Same as SX-7 Not featured in SX-5 Not featured in SX-4 3-point LED SIGNAL indicaror indicating signal strength of tuned frequency. Same as SX-7 TUNED indicator to show that broadcast station has been tuned. Same as SX-5 RadioFans.CN 收音机爱 好者资料库 Tuner Stage O I.D. MOS FET The FM front-end RF amplifier in model SX-? (and SX-6) features an I.D. MOS FET (ion-implan- tation dual gate MOS FET) - P001 manufactured by Pioneer Semiconductor Laboratory. The major features of this FET - P001 include high gain,Iow noise, Iow distortion and low IM (P.G. 25dB/ 100MHz, N.F. 2dBl100MH2, I.M. -54d8/107dBp) as a result of an extremely accurate short channel obtained by a self aligning operation involving a local silicon oxidation process. Furthermore, a O.4p narrow channel (1/3rd to 1/5th the width in normal components) has been achieved by the ion-implantation double diffusion construction. Use of this FET in the FM front-end greatly assists in improving sensitivity and reducing inter- ference. o Pulse-Swallow PLL Synthesizer When the VCO (Voltage Controlled Oscillator) frequency is very high and the CMOS progmmm- able divider operating frequency is exceeded, the PLL will cease to function. Two methods are presently available to resolve this problem. In one of these methods (the fixed divider system), an ECL (Emitter to Emitter Coupled Logic) prescaler is positioned in front of the programmable divider. And when, for example, a 1/10 prescaler is em- ployed to obtain 25kHz step frequencies, the reference frequency will be 2.5kHz. This frequency is very low and cannot be adequately removed by the low-pass filter. As a result, signal components are leaked into the mixer leading to deterioration in the S/N ratio. This is one of the main dis- advantages of the fixed divider system. The other method available is the pulse-swallow system which employs a special frequency divider called a two-modulus prescaler instead of the prescaler used in the fixed divider system. In this method, a 25kHz step synthesizer will generate a 25kHz reference frequency and a 50kHz step synthesizer will generate a 50kHz reference frequency, resulting in a much higher S/N ratio than in the fixed prescaler system. The pulse-swallow system employed in the SX-7 is incorporated in an IC (M54922P) controlled by microcomputer. Amplifier Stage o Non-Switching Amplifier (SX-7, SX-6, SX-s) In non-switching amplifiers, the output stage transistor bias is controlled on the basis of class B operating point in order to maintain the operation within the operating region (between cutoff and saturation) and thereby suppress the generation of switching distortion. The basic non-switching amplifier circuitry is outlined in Fig. 1-2. To simplify the diagram, transistor Vgn and diode Vg, E1 and E2 are assumed to be 0.6V and the transistor base current is disregarded. While no input signal is applied, the voltage drop across R5 and R6 may also be dis- regarded. And if the voltage across R1 and R2 due to idle current is ignored, the voltages at different positions will be as shown in the diagram. When an input signal is applied, a voltage will be generated across Rt by NPN stage (Q1/Q3) oper- ation during the positive portion of the signal. This voltage is applied to the Q5 emitter-follower (voltage gain of about 1) resulting in almost the same voltage being generated across Rb. This voltage is then added to the output stage bias voltage. Hence, the PNP stage (Q2/Q4) maintains the same bias conditions as when no signal was applied, which means there is no cutoff. Likewise, the NPN stage maintains the same bias conditions during the negative portion of the signal as when no signal was applied, again eliminating any cutoff. Fis. 1-1Pulse swallow system I Fig. 1-2 Basic circuitry of Non Switching Amplifier RadioFans.CN 收音机爱 好者资料库 Gontrol Stage The incorporation of microcomputers in these receivers has further simplified operational procedures. The PD6007 (SX-7) and PD6004 (SX-6, SX-5 and SX-4) ICs are both basically the same 4-bit microcomputer (with 2k-bit memory capacity), the main difference lying in the software program. Whereas the PD6007 incorporates a clock function, the PD6004 features a 2 band (LW/MW) AM tuner switching function. The PD6007 and PD6004 pin configurations are shown in Fig. 1-3. E Xlol Xlol REEEi tRo so sl scz ro T ro P r P2 Pr Oo O l O z U 3 O 5 O 6 V3s KI K2 K l KO STBY Fia Rr5 R r 2 H t l Rto R e R E R7 R6 d5 R4 R5 R2 R r RO Fig. 1-3 Pin configuration of PD6007 (PD6004) iSET rRo SF 5U fp I I P . Il LPo l-xo Il* l* LKo TC Rl3 Rt2 -n,r I I Ro 1 LRe t l-nz I LR6 R5 R. AF MUTE IND R3 VOL. MEMORY R2 VOL. lND. R r fo VOL. OATA I - our PUT | lo loo Lo. fo. DArA l- our PUT | lo Loo EXTAL CLOCK INPUT KEY INPUT CLOCK INPUT (5OOHz) SCAN STOP MUTING OtIT P.O.DATA / o)4., INPIJT 5-TH DIGIT o oR5 ol _ _ M54s22P ! | 5i- aM/ AJ cPs RE.ET PA4l c4 Fil C3 AM c2 PHOilO C AXIVIDOi, : ,.:, ., FUIICTION SELECTfi IC 10 Fig. 1-4 System diagram of control section (SX-7) RadioFans.CN 收音机爱 好者资料库 o Synthesizer Control Fig. 1-5 outlines the tuner-related computer operation command input key matrix. Key description 9k/10k : AM-MW band frequency step switch. ON for 9kHz steps, and OFF for 10kHz steps. 9k/1k (PD6004) : AM-LW band frequency step switching. ON for 9kHz steps, and OFF for lkHz steps. TUNING AUTO/MANUAL : ON for auto tuning (x1), and OFF for manual tuning. SCAN/SEARCH : ON for short-time hold search (x2), and OFF for operation according to TUNING AUTO/MANUAL switch (*6). FM : Display of tuned frequency by single push (*3), and pin 16 of synthesizer IC (M54922P switched to L level (x4). AM : Display of tuned frequency by single push (*3), and pin 16 of synthesizer IC (M54922P) switched to H level (x). LW/MW (PD6004) : LW-MW switching with each push. M1 - M8 : Trned frequency presetting keys. Cor- responding STATION indicator lights up (*5). TUNING UP, DOWN : Frequency tuning keys. MEMORY/STOP : Memory store enable key. STATION indicators (1 to 8) and the PRESET STEP indicator blinks on and off for 5 seconds when pressed once. A broadcasting station and volume step may be stored in memory during this 5 second period. And when pressed during frequency scanning, the scann- ing operation is halted. EL,E2 : Switching for different regions (USA, Europe etc.) Wired up according to region without switching. 81, B2 (PD6004) : FM IF offset adjustment. (*1) Station search where frequencies are scanned by pressing ?UN/NG UP or DOWN key once. Scanning stops when broadcast station frequency is tuned. (*2) Station scan where frequencies are also scanned by pressing TUNING UP or DOWN key once. Scanning pauses for 5 seconds when broad,casting station frequency is tuned. Scanning will be resumed after the 5 second pause unless the MEMORY/STOP hey is pressed. (*3) 16-bit serial d.ata from the SO pin is sent to the frequency display d,riuer IC (TD6301P), conuerted to 7-segment decimal