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Summary of Contents for CT-7000

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Page 2: ...YAMAHA Hi Fi STEREO SERVICE MANUAL FM STEREO TUNER MODEL CT 7000 Printed in Japan 10 74 ...

Page 3: ... 0 08 Wide less than 0 08 DIN 1kHz 40kHz Dev Normal less than 0 08 Wide less than 0 08 IHF 50 1O OOOHz 75kHz Dev Normal less than 0 3 Wide less than 0 15 DIN 50 10 000Hz 40kHz Dev Stereo Normal less than 0 3 Wide less than 0 15 IHF 400Hz 75kHz Dev Normal less than 0 08 Wide less than 0 08 DIN 1kHz 40kHz Dev Normal less than 0 08 Wide less than 0 08 IHF 50 10 000Hz 75kHz Dev Normal less than 0 5 Wi...

Page 4: ...CT 7000 EXTERNAL VIEW FRONT PANEL 1 REAR PANEL U S CANADIAN MODELS REAR PANEL EUROPEAN MODEL 2 ...

Page 5: ...MULTIPATH JACKS REAR PANEL EUROPEAN MODEL 0 ANTENNA SOCKET FOR 75 1 COAXIAL CABLE 8 300 1 DIN ANTENNA SOCKET 0 FIXED OUTPUT JACKS 8 VARIABLE OUTPUT JACKS 0 MULTIPATH JACKS m OUTPUT LEVEL CONTROL c MUTING LEVEL CONTROL Q MUTING SWITCH IF MODE SWITCH 41 METER DISPLAY SWITCH CD AUTO BLEND SWITCH CD MODE SWITCH CD ILLUMINATION SWITCH CD POWER SWITCH TUNING KNOB 0 IF OUTPUT JACK l GROUND TERMINAL 0 FUS...

Page 6: ... DEMODULATOR CIRCUIT BOARD 0 POWER TRANSFORMER 0 IF AMPLIFIER CIRCUIT BOARD 0 RF PACK fi DISCRIMINATOR CIRCUIT BOARD Ql METER LAMP CIRCUIT BOARD 4D PULLEY FOR VARIABLE CAPACITOR 0 CONTROL UNIT 8 VOLUME Cl RCUIT BOARD 0 SWITCH CIRCUIT BOARD 8 POWER SWITCH 0 CONTROL CIRCUIT BOARD 0 DE EMPHASIS SWITCH 0 POWER SUPPLY CIRCUIT BOARD ...

Page 7: ... ceived input from h rises above 10ciB u to saturation point app 30dB u at which time input is transferred to h to cover the 30dB u 50dB u range The I 3 terminal is for signals between 50ciB u and BOdB u while 14 CT 7000 Signal minus Multipath deflection This system permits the owner to find the best balance of strong and clean signals by switching between the two functions of this meter while exp...

Page 8: ...e AFC is off at the same t ime This gives rise to the f ollowing merits 1 If the AFC is c on stantly operating in the tuner then assuming that AFC caused frequency drift is 1 n the apparent selection zone is increased n times In such a case if there is a powerful stat i on nearby on the dial the tuning is apt to be pulled of f even du ring station selection which will make it impossible to tu ne t...

Page 9: ... lamp dims to show that the AFC is off Operation 1 When the Power switch is turned on When the power is switched on potential at point is equal to E and rises to 12V according t a time constant decided by Cl Rl When this 12V is added to the base of Trl this transistor switches on nd shuts Tr2 off so that the difference i n voltage obtained by ClRl appears as it is at terminal 0 This switches Tr7 p...

Page 10: ...tial which can be obtained by the discriminator S curve When the received signal is lower than the correct tuning point negative volt circuit also functions to cut transient noises a function which will be explained in another section age is contained in e2 when it is higher positive voltage is present b When the received signal is lower than the correct tuning point Tr1 is continually off but Tr2...

Page 11: ... of opposite phase are obtained At the same time this 38kHz signal is fed to the 2 POINTQ Fig 6 doubled multivibrator formed by Tr11 and Tr12 creating 19kHz square waves of opposed phase at points CD and Waveforms and phase relations at each time point are as shown below b As a principle of operation the oscillation frequency phase of the VCO rises advances as the Tr6 potential becomes more positi...

Page 12: ...int in the condition seen in chart 10 l when chart 4 is set to Tr3 also show the output at the point in chart 10 when chart 5 set to Tr2 a a CHART 10 obtained Since the 19kHz square wave signals driv ing Tr2 and Tr3 are in opposite phase Vc and Vd are activated alternately This phenomenon is then amplified by the differential amplifier formed of Tr4 and Tr5 d The phase relations between the pilot ...

Page 13: ...ng 1 b and 2 4 one can see that a locked condition is possible only when the phase dif ference is either 90 or 270 and the following con ditions hold a zone VCO works for phase retard b zone VCO works for phase advance c zone VCO works for phase advance d zone VCO works for phase retard Therefore the only stable locked condition is 270 phase difference with a 90 difference even a tiny retard will ...

Page 14: ...tector output the following points be come clear See chart 14 The operation to the detector when the PLL circuit is phase locked is shown by the chart 15 At this time the phase difference is zero and maximum posi tive output is obtained 4 The potential change is integrated by R3 and R4 and when it is more than 0 25V Tr5 goes on and Tr7 goes off which switches Tr8 on In this way the multiplex demod...

Page 15: ...e when a stereo signal is received Tr3 comes on Tr4 and Tr5 repeat seesaw on off motions at the 38kHz frequency which drives Tr6 and Tr7 When Tr4 is on Tr6 comes on at the same time Tr5 is Fig 8 off switching Tr7 off When Tr4 turns off it switches off Tr6 at this time Tr5 is on and thus so is Tr7 In this way the grounded open movement is repeated between points 0 and CV at the 38kHz rate permittin...

Page 16: ...hen take off the cover Photo 1 Photo 2 Photo 3 3 Power Supply Circuit Board Removal 3 1 Follow steps 2 1 and 2 2 3 2 Remove connectors 8 10 and screws 7 10 shown in Photo 4 then remove the power circuit board 4 Power Transformer Removal 4 1 Follow steps 2 1 and 2 2 4 2 Take off connector 10 shown in Photo 4 then remove the primary side leads 4 3 Remove screws 11 14 shown in Photo 4 while pressing ...

Page 17: ... Removal 8 1 Remove the cabinet 8 2 Loosen screws 9 and 10 shown in Photo 5 screw 3 shown in Photo 11 and screw 3 shown in Photo 12 then take off the shield cover 8 3 Loosen the two variable capacitor pulley fixing screws then remove the VC pulley 8 4 Unplug the input and output pin plugs then disconnect the connector 8 5 Remove screws 15 17 shown in Photo 4 then take out the R F pack 9 Meter Lamp...

Page 18: ... 1 Follow steps 12 1 through 12 5 13 2 Remove the headphone volume output level and muting knobs with a hexagonal wrench 13 3 Remove screws 1 and 2 shown in Photo 14 then remove the volume circuit board 14 Switc h Circuit Board Removal 14 1 Follow steps 12 1 through 12 5 14 2 Remove screws 3 and 4 shown in Photo 14 then remove the switch circuit board 15 Power Switch Removal 15 1 Follow steps 12 1...

Page 19: ...CT 7000 Photo 14 Photo 15 DIAL MECHANISM 17 ...

Page 20: ...0Hz 5Hz 98MHz 60dB u Unmodulated adjustment MPX circuit board 19kHz T P Frequency Counter 5 Stereo Distor Antenna terminal 300 2 IF circuit Set for minimum dis 60dB l 62dB 0 08 tion Ratio I FM signal generator board tortion IF MODE NORMAL Normal 98MHz 60dB u 100dB u VR201 202 100 dB l 57dB 0 14 Modulation 400Hz 100 TC201 202 60dB u stereo adjustment Fixed output jack L R required Oscilloscope Elec...

Page 21: ... the right Then carry out all steps after Step 15 2 When carrying out the IHF sensitivity check in Step 17 if the results do not satisfy the require ments adjust each RF pack core LA LR1 5 and each trimmer TCA TCR1 5 for maxi mum sensitivity For this adjustment however first repeat the adjustments and checks beginning with Step 1 3 When the power switch is off if the center meter does not indicate...

Page 22: ... vari 2 Unit Replacement U JIT NAME I ADJUSTMENT ITEM RF Pack Overall adjustment only when indl cater set point is out of adjustment IF Circuit Board Overall adjustment Discriminator Circuit Board Overall adjustment MPX Circuit Board 1 VCO Adjust 19kHz 2 Separation Adjust Normal 3 Output Level Adjust 4 Separation Adjust Wide Control Circuit Board 1 Separation Adjust Wide 2 Signal Meter Adjust Powe...

Page 23: ...tem S N Ratio Monaural Stereo Signal Generator Output Level Accuracy Modulation Degree Accuracy 75kHz deviation Signal Generator Spurious Residual FM factor at AM Radio Frequency Noise 300 1 Antenna terminal Equivalent 25 10 C 65 20 C 105 135V 90 115V 110 135V 200 240V 220 260V VALUE 45 65Hz 45 65Hz 45 65Hz 45 65Hz 45 65Hz Low enough to be no test influence more than 30 minutes Within 0 3d8 Within...

Page 24: ...CT 7000 22 PRINTED CIRCUIT BOARD WIRING CONNECTION DIAGRAM IF CIRCUIT BOARD NA06480 DISCRIMINATOR CIRCUIT BOARD NA06482 U S CANADIAN MODELS NA06481 EUROPEAN MODEL ...

Page 25: ...CT 7000 MPX CIRCUIT BOARD NA06483 23 ...

Page 26: ...CT 7000 CONTROL CIRCUIT BOARD NA06484 24 ...

Page 27: ...CT 7000 SWITCH CIRCUIT BOARD NA06487 POWER CIRCUIT BOARD NA06485 25 ...

Page 28: ...CT 7000 26 VOLUME CIRCUIT BOARD NA06488 MUTING OUTPUT LEVEL HEADPHONE LEVEL LAMP CIRCUIT BOARD NA06489 BLOCK DIAGRAM METER LAMP CIRCUIT BOARD NA06490 ...

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Page 30: ...CT 7000 PARTIAL CHANGES MADE ACCORDING TO DESTINATION T POWER U S CANADIAN MODELS EUROPEAN MODEL T ANTENNA EUROPEAN MODEL 29 ...

Page 31: ...CT 7000 PARTS LIST FRONT VIEW INTERNAL VIEW 31 ...

Page 32: ...CT 7000 INTERNAL VIEW EXPLODED VIEW 24 32 ...

Page 33: ...CT 7000 INTERNAL VIEW INTERNAL VIEW BOTTOM 33 CT 7000 INTERNAL VIEW INTERNAL VIEW BOTTOM 33 ...

Page 34: ...CT 7000 EXPLODED VIEW BACK VIEW EUROPEAN MODEL BACK VIEW 34 ...

Page 35: ...resistor SV10KR 82200 IJ v R iC04588 Transistor 2SC458 B or c 1 7 A11 iC04608 2SC460 8 or c iE00009 FET 25K19 GR F E T iF00033 Diode 15188 FM1 9 1 t iF00004 151555 iG00040 IC TA7060P I c iG00039 IC uPC577H I c GE10018 FM 1FT GE10018 F M I F T 8806336 IF shield frame No 6336 I F l F rl LB10009 Pin jack 503055 t 1 LB60052 Connector housing No 2145 68 J 1 J 1 l j NA06481 Dis c riminator circuit board...

Page 36: ...1P J y J LB30022 Connector 2145 38 J 1 J J 9 BB06337 Discriminator shield frame No 6337 71 7 J JL t NA06483 MPX circuit board j l 63473 M p X 1 HU47620 Metal film resistor F 1 2KO j g Iii HU47633 3 3KO HU47622 2 2KO HU47647 4 7KO HU47656 5 6K0 HU47710 10K0 HU47722 22KO HU45610 J 5 1KO HU45633 3 3KO HU45710 10KO HU45739 39KO HU45810 100K 1 FD19330 Polystyrene capacitor F t1 3000PF 7 7 J 117 1 1 FG1...

Page 37: ... B or C 2SC458LG C or D 151555 WZ 061 WZ 130 6P 2145 68 t63503 Metal glaze variable resistor CR19R B22K Ceramic capacitor 50V SL F tl 3P Tantalum capacitor 10 f F 16V 0 22 u F 35V 1 uF 35V 2 2 f F 35V MPX fixed coil 47mH RF inductor 10 uH Transistor 2SA561 0 or Y 2SA763 WL4 or 5 2SC458 B or C 2SC460 B or C 2SC734 0 or y FET 2SK30A y Diode 151555 15188 FM1 Zener diode WZ 061 Slide switch SL222B4 CT...

Page 38: ...612 Transistor 2SA561 0 or Y 7 7 ll iA07630 2SA763 WL 4 or 5 iC04588 2SC458 8 or C iC07343 2SC734 0 or Y iC10613 2SC1061 8 or C iE00002 FET 2SK30A GR F E T iF00032 Zener Diode WZ 061 I z7 1f1 t I iF00022 WZ 310 iH00003 Diode 10D 1 5f 1 t F iH00008 10DC 1 iH00009 10DC 1R iH00005 10DC 2 iH00013 10DC 2R L840013 Connector 2403 4A J 7 J titift7 X L860054 2403 BA L860055 5015 8A NA06487 Switch circuit b...

Page 39: ...G15S 63870 63970 AW R 150 mm R 300 mm B 10K0 A 10Kx2 Coaxial cable with pin plug 12 570 mm Panel unit Hing spring Rolling panel Dial glass Sub panel Variable resistor knob Push button Headphone jack JH5020K Phone nut Dial scale unit Dial pointer unit Lead type lamp 12V 60mA SignaI meter Tunig meter Tuning unit Power transformer assembly CT 7000 Remarks Common MOdels AT g rn 7 7 1 a 1 7 7 51 7 7 1 ...

Page 40: ...èţ ţ G éţ à ţ êţ Ê ţ R ţ k šď Ĝţ i ţ ĵĬĭ Ř ʼnţ ĕ ţ Î Nţ Į įr ţ v AĐ2 ţ bţ ÅÓ ţ ţ w İ ïţ Œ ò ţ Ä ţ ţ Ŋ 0 þ o ţ bđ ţ Ēf Ĕţ ţ ţ ţ Xţ 4 ţ ÎŜ ţ Ć Ğ tţ Î Ŗ5ķ ţ Î Àº Î Î â ţ Þ ı ŗŞŌ ţ üşDmţ H M ţ U ţ Ô X 67ţ ţ Õţ N ţ ÏZ ţ ţ eţ ţ eţ ţ ţ rţ Dţ ÄÅÎ Î QÎ 2 Î Æřĺ ĸ 0ţ Ĵ nţ B B B B LÎ 8 Î n ef dÍÆ Î 5B Î gÎ B MÎ Î Î Î B Î B B X Î Â Áà ţ B B B ţ ÃÌ a 0Î Î ÂÊU V 3Î Î RÎ DÎ 0AB B B AÎ B 1B 7B 2B CÎ Î E Á Î B BÎ B ...

Page 41: ...d U d d d T d d d TS d WHSd ETYd SSB TYd T d 4d 01 6 O IJ _ d d B_BYd ZaH Gd c0UaBYd ZaH G d d 2 9W9SBZBd SAd 5 3 d RABOZd d d YTX Sd QVBOd 8 d 3W YMd LHOOBYd d d d 9W SBZBd 9SAd W P QTABNZd 8 d 0HS 0JSd SSB JTSd 9 OBd U d d d d 4d 6d R 9W SBZDd QUABOd d d 6d 5 3 d QTABOd d HSK9 YBd E ZBd 4d 6d Y T D YTWB Sd QTABOd d 4d 6d d 3BY J Bd W Ad U d d G S 5 3 d 9SAd YTWB9Sd QUABOZd 8 d d A Q9 Gd 9S BSS9d...

Page 42: ...Printed in Japan 10 74 m 1887 YAMAHA NIPPON GAKKI CO LTO HAMAMATSU JAPAN ...

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