Pioneer-TX9500MKll-tun-sm电路图 维修手册.pdf

- -l;) -4 n t.1i t ( A-a r- . *!:4.- fe; f)- (6. oto -* * IIJSlll (DrqoNEErl RadioFans.CN 收音机爱 好者资料库 Type Voltage Remarks KC120V only CSA (Canada) approved with de-emphasis selector switch (25psl75psl KU 120V only UL (U.S.A.) approved with de-emphasis selector switch l25trs/75psl HG 22OY and 240V (Switchabte) SEMKO (Sweden), NEMKO (Norway), DEMKO (Denmark) and El (Finland) approved S110V, 120V, 22OV and 240V (Switchabte) General export model with de-emphasis selector switch l25ysl50ps/75psl TX-g5ClCltr MODEL TX-gsOOII COMES tN FOUR VERSIONS DISTINGUISHED AS FOLLOWS: . Service informations for TX-9500II/KU is described on page 5 through 52 in this manual. o For servacing of Kc, S and HG types please refer to TX-9500II/KU manual with the exception of descriptions in the Additional Service Manual (p.53-p.86). CONTENTS 1. 2. 3. 4. 5. CONNECTION DIAGRAM SPECIFICATIONS BLOCK DIAGRAM 5 6 7 I FRONT PANEL FACILITIES CIRCUIT DESCRIPTIONS 5.1 AM Tuner 5.2 FM Tuner DISASSEMBLY 5.3 REC LEVEL CHECK 5.4 Power Supply Circuit Signal Generator Circuit 11 11 15 6. 7. 15 16 20 21 PARTS LOCATION 7.1 Front Panel View 7.2 Front View with Panel Removed 17 18 19 7.3 Top View 7.4 Rear Panel View 8. DIAL CORD STRINGING RadioFans.CN 收音机爱 好者资料库 9. ADJUSTMENTS 9.1 FM Section 22 9.2 AM Section 26 10. EXPLODED VIEWS 10.1 Top Side 27 1O.2 Bottom Side . 29 10.3 Nomenclature of Screws, Washers and Nut . . . . . . 31 11. PACKING 32 12. SCHEMATIC DIAGRAMS, P.C. BOARD PATTERNS AND PARTS LIST 12.1 Schematic Diagram and Miscellaneous Parts List 33 12.2 FM Front End (AWB-023) . 36 12.3 AM FM lF Assembly (AWE-070) . 37 12.4 MPX AF Assembly (AWD-009) 45 12.5 Power Supply Assembly (AWR128) 50 Additional Service Manual 1. CONTRAST OF MISCELLANEOUS PARTS 54 * 2. KC TYPE 2.1 Schematic Diagram and Miscellaneous Parts List 2.2 Power Supply Assembly (AWR-I29) 2.3 Packing 3. HG TYPE 3.1 Schematic Diagram and Miscellaneous Parts List 3.2 MPX AF Assembly (AWD-008) 3.3 Power Supply Assembly (AWRI30) 3.4 Packing 4. S TYPE 4.1 Schematic Diagram and Miscellaneous Parts List 4.2 MPX AF Assembly (AWD-010) 4.3 Power Supply Assembly (AWR-I31) . . . 4.4 Switch Assembly (AWX-113) . . 4.5 Packing 56 59 61 62 65 70 73 74 77 82 85 86 RadioFans.CN 收音机爱 好者资料库 1. SPEC|FtCATIONS Semiconductors 5 15 FETS lCs Transistors .12 Diodes .19 FM Section Circuitry . . . MOS FET 2-stage RF ampli- fier, 5-gang variable capacitor, lF Band Selector, Wide-band linear detector, doublebal- anced NFB type PLL MPX b u ilt-in p ilot signal auto cancel ler. Usable Sensitivity . . MONO: 8.8dBf (1.59V) 50dB Quieting Sensitivity . . MONO: 13.2dBf (2.5tN) STEREO: 36.1dBf (35pV) Signal-to-Noise Ratio at 65dBf MONO: 82dB STEREO:71dB Distortion at 65dBf MoNo: wlDE NARRow 100H2 0.05% O.OIY, l kHz 0.05% O.jlY 10kHz O.07o/o 0.1Yo 15kHz 0.12Y STEREO: 100H2 0.17o O.3Vo l kHz 0.07o/o 0.25% lOkHz 0.2Yo 0.5%o 15kHz O.57o Capture Ratio. . . 0.8d8 2.0d8 Alternate Channel Selectivity. . . 35dB 85dB StereoSeparation. .lkHz: 50dB 45dB 50Hz to 1 5kHz: 35dB 30dB Frequency Response 20Hz to 10kHz+0.2dB 2oHz to r stHzlooaa Spurious Response Ratio . . 11OdB lmage Response Ratio . . . . 120d8 lF Response Ratio . 105dB AM Suppression Ratio . . . . 65dB Muting Threshold . . 19.2dBf(5 ttY),34.1d8f(28pv) Subcarrier Product Ratio . . 11dB SCA Reiection Ratio . . . . . 62dB Antennalnput . . 30Oohmsbalanced 75ohms unbalanced TX-s|5clCltr AM Section Circuitry .lstageRFamplifier3-gang variable capacitor Sensitivity lHF,ferriteantenna . . 300pV lHF, external antenna . . 15pV Selectivity . . 30dB Signal-to-Noise Ratio. . . . . 55dB lmage Response Ratio . . . . 70dB lF ResoonseRatio . . 65dB Antenna . Built-in ferrite loopstick antenna Audio Section Output ( Level/l m pedance) FM (100% MOD.) FIXED: 650mV/4.2kO VARIABLE: 50mV to 1.3V/3.6ks2 AM (30% MOD.). FIXED: 2OOnYl4.2kQ VARIABLE: l5mV to 400mV/3.6kO Miscellaneous Power Requirements 120V 60Hz only. PowerConsumption . . . . . 25W Dimensions . a20(W)x150(H)x395(D) mrr 1 6-9 | 1 6x5-7 18x1 5-9l1 6 in Weight . WithoutPackage: 9.5kg (201b 15oz) With Package: 1 1.0kg (241b 4 oz) Furnished Parts FMT-typeantenna .1 Operatinglnstructions .1 ConnectionCordwithPinPlugs .I Hex. Wrench (used forfasteningTuning knob) . . . . . . . 1 NOTE: Specifications and. the design subject to possible modifica- tion without notice. /r l 2. CONNECTION DIAGRAM FM DE.EMPHASIS SWITCH Normafly, set this s,witch to 75tts. Be sure to set it to 25ps. only when listening to an FM broadcast (pre- emphasis: 25psl with a Dolby* system. TX-9500 GROUND OSCI LLOSCOPE * The word Dolby is a trademark of Dolbv Laboratories Inc. T TYPE FM ANTENNA FM OUTDOOR (if stations are nearby) ANTENNA AM ANTENNA (indoor or outdoorl t DISCRETE 4CHANNEL FM ADAPTOR ! t I -) I I *-J-= rl I i- AM FERRITE BAR ANTENNA CONVE OUTLET coupled v power sr, t - | tl t=J : N l E N r iT (not I with witch) l lr _JTII power l f - l l s tl I lr5 L- oosoo16;sO bossoifdon TAPE DECKSTEREO AMPLIFIER 3. FRONT PANEL FACILITIES POWER SWITCH Set to ON position to turn on power. Pilot lamp will light. MULTIPATH ON: Multipath sound becomes audible from speakers. When installing FM antenna, select antenna location and direction so as to minimize this sound. Normally set switch to this position. REC LEVEL CHECK ON: Use this position for setting recording levels of tape deck. A 44OHz signal (level corresponding to 50% FM modulation) is produced at approxi- mately 1.7 second intervals. SIGNAL METER Employ when tuning AM tuning point occurs when toward the right is obtained. and FM stations. Optimum maximum meter deflection TUNING Use when deflection tune carel (optimum MUTING Controls noise whr tuning opr 2: OFF: PILOT LAMP IF BAND SWITCH FM lF (intermediate for wide or narrow. frequency) passband can be set to WIDE:Normally set switch to this position. NARROW: lf adjacent station interference is a pro- blem at the WIDE setting, set switch to this position. MULTTPATH/REC LEVEL CHECK SWTTCHMEMORY MARKERS Single lever operates both MULTIPATH and REC LEVEL CHECK switches. With the FUNCTION switch at FM, set as required for the application. Be sure to return it to the OFF position when it is not being used. tF BAND INDICATOR Convenient for designating most often tuned in stations. Slide markers with fingertip to desired positions. OUTPUT LEVEL CONTROL Adjusts level at OUTPUT (VARIABLE) jacks. Clockwise rotation increases output level. OFF: ;. Optimum deflection TUNING METER Use when tuning FM stations. First tune for maximum deflection of the SIGNAL meter (tov,ard the right), then tune carefully so that the meter indicates center of scale (optimum tuning point). oraorueen srEFEo ruNEr il-9500l MUTING SWITCH Controls circuit for cancelling bothersome interstation noise when tuning FM stations to provide a comfortable tuning operation. TX-s|5ClCltr FM STEREO INDICATOR with the FUNCTTON switch set to FM AUTO (or FM NOISE FILTER), the indicaror will light during stereo signal reception. FUNCTION SWITCH Switch for selecting type of reception. AM: AM broadcast reception. FM AUTO: FM stereo reception. lf broadcast is FM mono, the mono mode is automatically selected. FM NOISE FILTER: Ser to this position if compara- tively high frequency noise becomes objectionable during FM stereo reception. Note that some loss of stereo separation occurs at this position. FM MONO: FM monophonic reception. Set to this position if reception at FM AUTO posi- tion is noisy or signals weak. TUNING KNOB Knob for selecting stations. Refer to the SIGNAL meter when tuning AM stations and to both SIGNAL and TUNING meters when tuning FM stations. )ICATOR ) -_l I _l Clockwise 2: 1: OFF: Set to this position to receive only strong stations. lf desired station cannot be received at position 2, set switch to this position. Set to this position in locations where signals are extremely weak. a 4. BLOCK DIAGRAM FI, FRONT END l- Rr -; - RF am; - f1i* !. crq rctr*l -5.l r4 I lri ,F I lrefl + It- -i-L- -_ -/ t L-r I SWITCHES. Sat FUNCTI0N 1. AM 7. Fl Sz,r,b : MUTING 1 OFF 7. S:ad f40DE 1. IIULTiPA S4a,b lF BAND NARROW <- (. v J 5 5 F X I L 15o t 3000 L CND Loca | 0SC POW ER 0N AC LINE S , q t 6 o Stn 5os o Q+va 3 L . P F . 3 AF MUT. IC -_Jl REC LEVEL OSC. l-r-.l rLs.- -i I o q. I J U l*r L-r | src I I Sa L l_ _ L _) POWER SUPPLY 5. CIRCUIT DESCRIPTIONS 5.1 AM TUNER The major components of the AM tuner are the 3-ganged variable capacitor, a newly developed IC (HA1197), and an AM ceramic filter. A block diagram of the HAlL97 is shown in Fig. 1. This IC consists of an RF amplifier first stage, followed by a mixer stage which also includes a self-oscillating local oscillator, the IF amplifier 3rd and 4th stages, and a detector circuit final stage. The AGC (Automatic Gain Control) receives an AGC voltage from the output of the detector cir- cuit, and applies it to the RF amplifier and IF amplifier stages. The advantage of the HA1197 is a large reduction in the distortion at low frequencies. Whereas the distortion at 100H2 was 1.57o in the previous HA1138, this figure has been reduced to 0.4Vo (LOOHz) in the HA1197. TX-s|Eclcltr 5.2 FM TUNER FM Front-end The FM front end is composed of a tuning circuit employing a 5-gang variable capacitor, a 2-stage RF amplifier a mixer employing dual gate MOS FETs, and a local oscillator with buffer. An equiva- lent of a cascode amplifier is produced by AC grounding gate-2 of the dual gate MOS FET, allowing stable RF amplification at high gain. The output signal of the RF amplifier is applied to gate-l of the mixer stage MOS FET, while the local oscillator output signal is applied to gate-2. This technique minimizes input power from the local oscillator, resulting in low mutual interference even if the received signal input level is high. A variation of a Clapp circuit forms the local oscillator. Inclusion of a buffer amplifier between local oscillator and mixer reduces local oscillator load, eliminating distortion of the oscillation wave- form. Drawing effect of the local oscillator is also eliminated. AF out Fig. 1 Block diagram of HAl197 2nd RF amp FM 75O UNBAL. t- FM 3OOO BAL. L Ceramic filter ANT To SIGNAL Meter AGC line 1st RF amp. Local oscillator Fig. 2 Circuit of FM front end FM lF Amplifier In this FM IF amplifier, there are two selectable IF frequency pass bands,viz. WIDE band and NAR- ROW band, selected by the IF BAND switch. This circuit is shown in Fig. 3. The SAW (Surface Acoustic Wave) filter used in the WIDE band circuit, is a filter which works on entirely new principles. Signals are carried across the piezoelectric element surface by mechanical vibrations. The advantages of this SAW filter in comparison with a 2-element ceramic filter, is that the group delay time flatness characteristics cover more than twice (500H2) the band width while still maintaining the same degree of selectivity. The tetra-polar phase linear filter makes use of the SAW filter characteristics to further improve the degree of selectivity. Consequently, the WIDE band circuit has been designed with the aim of even further improving the distortion factor. The NARROW band circuit employs 5 2-element ceramic filters for very good selectivity. This cir- cuit is outstanding in its ability to reject interfering signals, and is particularly suitable for areas where adjacent stations are crowded very close together on the FM band. The distortion factor too, is very close to the value obtained in the WIDE band. Switching between the WIDE and NARROW bands is accomplished by switching a +B voltage supply ON and OFF. But since the IF amplifier in the NARROW band circuit is the same IF amplifier used to operate the meters and the muting func- tion, the +B voltage supply for the final stage IC and diode (Dt) would also be turned ON and OFF. Switching the +B voltage supply for Dt ON and OFF will cause D1 to act as a switch. When the +B voltage is applied to the anode of D1, Dr is put into a conducting state, with the signal passing into the next stage. Following the IF amplifier in NARROW band, or following the WIDE band circuit there is a 5-stage wide-band IF amplifier which produces sufficient limiter effect. FM Detector The detector circuit used in the TX-9500II is a super wide band linear detector circuit, a product resulting from the study of distributed constant type detectors. The circuit is shown in Fig. 4. M5109PR included in this circuit is an IC incor- porating 2 pairs of differential amplifiers. The loads of each differential amplifier are connected to a series resonance circuit where the L16, C3t resonance frequency is higher than the inter- mediate frequency (10.7MH2), and the L,r, C., resonance frequency is lower. The IF outputs from each of these differential amplifiers are modulated to the AM components which are then detected by Dr - D6. Sz : MUTING OFF-I- 2 Sr : MODE IVULTIPATH-OFF-REC LEVEL CHECK ON Sa : lF BAND WIDE NARROW +Br +Be +d3 WIDE IF IF AMP. t DETECTOR M PX IC ( PA100t ) AF MUT IC (PAl002) I Fig. 7 FM control circuit order to prevent muting when the FUNCTION switch is tumed to the AIVI position. In this case +Bz is applied to the bases of both Q1e and ez, turning Qre OFF, and Qz ON. Therefore, terminal no.8 of PA1002 is connected to ground, thus pre- venting the muting circuit from operating. The muting action is also inhibited when the MODE switch (S3) is tumed to the REC LEVEL CHECK position. In this case, the MODE switch shorts terminal no.8 directly to ground. Fig. 8 Block diagram of PA3001 5.3 REC LEVEL CHECK SIGNAL GENERATOR CIRCUIT This circuit, consisting of one transistor and an IC c:t n+r TX-s|5clcltr (HA1452W), produces tone bursts every 8.4 sec. for 1.7 sec. intervals by means of. a 440H2 signal. The output level corresponds to a value equivalent to an FM broadcast with 5O7o modulation. The cir- cuit is outlined in Fig. 9. The IC HA1452W incorporates two pairs of opera- tional amplifiers, one being used as a 440H2 sine wave oscillator circuit, and the other as square wave oscillator, which cycles on and off every 3.4 sec. for 1.7 sec. The switching action of e, con- verts this square wave into tone bursts. When the square wave is applied to the base of e, , e, is tumed ON and OFF, thus converting into a 440H2 tone bursts. 5.4 POWER SUPPLY CIRCUIT This circuit, too, employs one of Pioneers recently developed ICs (PA2002), resulting in better S/N ratio, stability, and a greater degree of reliability. PA?OO2 is an IC used to provided constant volt- ages, and incorporates a protection circuit. A block diagram is outlined in Fig. 10. The protection circuit is composed of control cir- cuits activated by overcurrents, and control circuits activated by overvoltages. The protection circuit is activated when either a current in excess of 760mA (resulting from an overload) flows through the IC output (terminal no.10), or a voltage in excess of 27V is