Yamaha-T80-tun-sm(1) 维修电路原理图.pdf

STEREO TUNER I(FRON+ PANEL HCONTENTS . TO SRVICE PERSONAL 1 . SPEClFICATlONS 1 . REARPANELS 2 . DISASSEMBLY PROCEDURES 3 . INTERNALVIEW 4 . . ADJUSTMENT . 4 19 BLOCKDIAGRAM . 10 PRINTED ClRGUlT BOARD . 11 13 WIRING DIAGRAM . 14. 15 SCHEMATIC DIAGRAM . 16. 17 EXPLODED VIEW . 18 PARTS LIST . 19 27 NIPPON GAKKl CO., LTD . HAMAMATSU . JAPAN 1 I W - q Q l Printpd in laoan RadioFans.CN 收音机爱 好者资料库WTO SERVICE PERSONAL 1. Critical Compnentt Information. Components having special characteristics are marked A and must be replaced with parts having specifications equal to those originally installed. 2. Leakage Current Measurement (For 120V Model Only). When service has been completed, it is imperative that you verify that all exposed conductive surfaces are properly insulated from supply circuits. EQUIPMENT AC LEAKAGE TESTER Meter impedance should be equivalent to 1500 UNDER TEST or EQUIVALENT ohm shunted by 0.1 5pF. Leakage current must not exceed 0.5mA. B Be sure to test for leakage with the AC plug in WALL both polarities. OUTLET INSULATING TABLE - IISPECIFSCATIONS FM SECTION Tuning Range . 87.6 - 108.OMHz 50 dB Quieting Sensitivity . . . . . . . . . . . . Mono (DX) 1.6pV (15.3dBf) . . . . . . . . . (NR ON) 1.2pV (12.8dBf) Stereo (DX) . . . . . . . . . . . . 20pV (37.2dBf) . . . . . . . . . . (NR ON) 1OpV (3i.2dBf) h b l e Sensitivity (IHF Mono) 75a . . . . . . . . .0.9V (10.3dBf) Usable Sensitivity (DIN) . . . . . . . . . . . . Mono (SIN 26dB). .l .OpV (E) . . . . . . . . . . . . Stereo (SIN 46dB) .3.OpV (E) I-e Rarpoma Ratio . . . . . . . . . . . . . . . 9548 . . . . . . . . . . . . . . . . IF Rslponro Ratio .l 15dB . . . . . . . . . . . . Spurious R-ms Ratio. .l l OdB . . . . . . . . . . . . . . . AM Suppression Ratio 70dB Capture Ratio Local . . . . . . . . . . . . . . . . . . . . . . . 1.2dB Alternate Channel Selectivity DX . . . . . . . . . . . . . . . . . .85dB (U,C,R,A) Selectivity (two Signak)(DIN 40kHz Dev.) . . . . . . . . . . . . . . . . . . . . . . DX 70dB (E) Adjacent Channel Selsctivity DX . . . . . . . . . . . . . . . . . . 20dB (U,C,R,A) Signal to Noise Ratio (IHF) . . . . . . . . . . . . . . . . Mono .94dB (U,C,R,A) . . . . . . . . . . . . . . . Stereo :86dB (U,C,R,A) Signal to Nobe Ratio . . . . . . . . . . . (DIN-Weighted) Mono 88dB (E) . . . . . . . . . . Stereo. 80dB (E) Harmonic Distortion . Mono 100Hz. .DX0.03%, Local 0.02% (U,C,R,A) . . 1 kHz .DX0.15%, Local 0,03%(U,C,R,A) 6kHz . . .DX0.4%, Local 0.06% (U,C,R,A) Stereo lM3Hz . .DX0.5%, Local 0.04% (U,C,R,A) 1 kHz . .DXO.5%, Local 0.03% (U,C,R,A) 6kHz. . .DX0.8%, Local 0.07% IU,C,R,AI (4OkHz Dev) Stereo 100Hz . . . . . . DX 0.5%, Local 0.05% (E) l kHz . . . . . . . DX 0.5%. Local 0.04% (El . . . . . 6.3kHz. OX 0.5%, Local 0.08% (E) Strreo Separation (IkHz) (Local) mkHz. a. .65dB 1 kHz. . . . . . . . . . . .65dB (U,C,R,A) 60dB (E) 10kHz . . . . . . . . . . . 50dB (U,C,R,A) 40dB (E) F-affiy Raporar 0+O.d9 . 50Hz to lOkHz . -0.3 Subcarrier Product Ratio . . . . . . . . . . . . . 65dB Metat Saturation Level . . . . . . . . . -3mV (75dBf) AM SECTION Tuning Range . . . . . . . . .510 - 1620kHz (U,C,R) 513 - 1620kHz (E.A,R) Usable Sansitivity . . . . . . . . . . . . . . . . . ,250pV Selectivity. . . . . . . . . . . . . . . . . . . . . 30dB Signal to N o b Ratio. . 55dB Image R w n s e Ratio . . . . . . . . . . . . . . . 40dB Spurious Response Ratio. . . . . . . . . . . . . . 50dB Distortion (400Hz). . 0.2% AUDIO SECTION Output Levelllmpedance (HIGH) FM (100% MOD, 1kHz) . . . . 1V/2ka (U,C,R,A) 1.6VI2kS2 (E) . FM (30% MOD, 400Hz) 0.3VIZkn . REC CAL (50% MOD, 333Hz) 0.5V12kn ., Output Level/lmpedanee (LOW) i FM (100% MOD, IkHz) . . 0.5VI2.5ka (U,C,R,A) 0.8V12.5kn (E) AM (100% MOD, l kHzl . . . . . . . 0.15V12.5kSZ REC CAL (50% MOD, 333Hz) . . . 0.25VI2.5kn GENERAL Power Supply . . . . . . . . U.S. & Canadian Models 120V, 60Hz . . . . . . . . . General Model. l 1 011 20V, 50/60Hz 220/240V, 50/60Hz . . . . . . . . . . . . European Model. 220V, 50Hz +,.K , 240V, 50Hz . . . . . . . . . . . . Australian Model 240V. 50Hz Power Cbnspmption- U.S. & Canadian Models . . . . . . . . . . . . . 13W . . . . . . . . . . . . . . . . . . General Model. 13W . . . . . . . . . . . . . . . . . . European Model. 13W . . . . . . . . . . . . . . . . . Australian Model 12W Dimemion ( W X D ) . 435 X 93.5 X 357rnm (U,C,R,A) (1 7-7 18 X 3-1 132 X 14-1 116) 435 X 93.7 X 357mm (E) (19-118 X 3-1/32 X 14-1/16) Weight-. . . . . . . . . . . . . . . . . . . . . . . . . 5kg (Illbs) Specifications subject to change without notice MARKET U: U.S.-Model C: anadbn Model R: General Model ,. :. .,-: -, . , . ., . . : r g & + * % & & & g F $ g - & ? ; 2 A: Australian Model J: Japanese Model - . - . -. . -. .,- . . -1. RadioFans.CN 收音机爱 好者资料库WREAR PANELS U .S .& CANADIAN MODEL EUROPEAN MODEL GENERAL MODEL AUSTRALIAN MODEL POWER TRANSFORMER U. S. & Canadian models: GA67130 European model: GA67 140 General model: GA67 120 Australian model : GA67150 TUNER CIRCUIT BOARD AM LOOP ANTENNA FRONT END Cl RCUIT BOARD POWER SWITCH (SW203) IC114 : LC6502C-638 IC113:LC7210 KEYBOARD UNIT CIRCUIT BOARD LED FREQUENCY & SIGNAL INDICATOR 1. Before Adjustment 1) Start adjustment approximately 5 minutes after the power switch is pushed on in order to stabilize the operation of circuit. 2) Adjust the OSC coil and I FT using high-frequency or nonferrous screwdriver. 3) Adjust the FM section first. After that, adjust the AM section. 4) Set the switches to the following positions unless otherwise specified. TUNING MODE. . . . . . . . . . . . . . . . . . AUTO RECCAL . . . . . . . . . . . . . . . . . . . . . . OFF 5) Be sure to make adjustment after installing the bottom cover. 6) For connection with OUT PUT, use HIGH terminal. Check to see if the specified voltage is provided across each terminal and E in the tuner circuit board. 2. Measuring Instruments Abbreviation FM SG . FM signal generator SSG . Stereo signal generator AM SG . AM signal generator OSC . Oscilloscope DlST M . Distortion meter FC . Frequency counter ACVM . AC voltmeter Center meter . Ji00036 or equivalent DCVM . DC voltmeter Use 19kHz L.P.F for OUTPUT L and R terminals and make auditory compensation. Then connect the os- cilloscope, AC voltmeter and distortion meter. To check the optimum tuning point during adjust- ment, connect the auxiliary center meter (Ji00036 or equivalent, current sensitivity: 250pA) as shown in the figure. The accuracy of FM SG should be within +l kHz. N Vcc T.M NOTE: 70dBp = 75.4dBf, 60dBp = 65.4dBf. of auxiliary center to check again. If meter is positioned the pointer is posi- at zero (center). pointer of auxiliary center meter posi- tioned at zero (center) R197 and. J150 to force stereo mode. 2. Adjust until the frequency across 5 98MHz + l kHz aural distortion is LOCAL mode. PLL input phase adjustment + 12 (.l1501 19K (C169) 3002 FM ANT OUTPUT FC terminals C169 and E becomes 19kHz i ? lOHz. FM S G Stereo ( L-R) modulation OSC l ncrease output to maximum. Remove FC and 2.2M52 resistor. output is increased to maximum. R channel alone: adjust OUTPUT Lch VR103 until output is increased level to minimum. 9% modulation 98MHz + l kHz open across itivity is deterio- d with FM ATT 98MHz + l kHz 10kHz output differs between when the FM NR switch is at ON and OFF position. Connect the AM loop antenna to the AM ANT terminals. 0 Connect the AM dummy used for adjustment to AM SG. The accuracy of AM SG should be within kO.1 kHz. i i adjustment l l l I 1 up when tuned. 0 3 Auto reserarch reception con- f irmation By shorting across the terminals TP(K4) and TPITG) in i-2. ,-:;ode, AM 1,08OkHz, FM 92.6 MHz and FM 98.OMHz are automatic:;.! stored into preset memories 8 to 10 respectively. AM ANT AMSG TUNING Make sure that auto search reception can UP, DOWN be made w t h the 400Hz 30% modu- TUNING button for lation both UP and DOWN adjustment, re- adjust VR204. Sensitivity con- I firmation l i TUNING MODE SW -+AUTO AM ANT AM SG 630kHz r 0.1 kHz 1440kHz + 0.1 kMz 1080kHz + 0.1 kHz (400Hz 30% modu- lation) switches and con- indicator above the PRESET ed, respectively. .In the same way, store the AM The TUNING MODE LED turns manuallmono MODE switch to operation con- be made with the TUNING button for UP and DOWN oper- ations. Also confirm that when FM is re- ceived, forced mon- 1 /OUTPUT OSC,DlSTM ! L o r R I I I VR204 Adjust so that all sig- I nal indicators light Confirm sensitivity by checking to see if tuning is made at the standard values. 2 / Fun-scale signal i I level indicator ,? 1 When VR210 has I been turned after AM ANT AM SG /1080kHz t 0.1 kHz 58dBor lower 58dBb or lower 58dBb or lower . Who? sensitivity i s improper, ad- just a s described in steps (l l to (5). quency indicator. (When FM is or - switch. switch is pressed, the following 3 memory opera- frequency in P2 is displayed and tion confirma- the P2 LED turns on. seconds have -r When the POWER switch is ON MODE switch to turned on, the frequency in P1 IN ITlAL STATION is displayed without respect to the frequency which is displayed before the POWER switch is turned off. Therefore, before turning off the PWER switch, display a frequency which has . After 5 or more t this time, confirm that the seconds have pass- frequency in P1 is displayed and ed, turn on the TUNER CIRCUIT BOARD I Connect resistor across R467 to 5268, Full-scalle signal level indicator 1 Separation adiustrnent 1 l adiustment Center Meter (Ji 00036 or equivalent) m 7FM FRONT-END SECTION DC NFB MPX DECODER SECTION CIRCUIT BOARD (Panern Side) FRONT END CIRCUIT BOARD