Amc-XT-tun-sm维修电路原理图.pdf

《Amc-XT-tun-sm维修电路原理图.pdf》由会员分享，可在线阅读，更多相关《Amc-XT-tun-sm维修电路原理图.pdf（8页珍藏版）》请在收音机爱好者资料库上搜索。

1、STEREO TUNERRadioFans.CN 收音机爱 好者资料库TUNER ALIGNMENT PROCEDURE FM SECTION A. PREPARATION 1. Set stereo modulator to mono mode with 1KHz modulating signal unless otherwise state. 2. Set signal generator to FM mode with 75KHz deviation. 3. Store the following frequencies: 87.5MHz, 90.1MHz, 98.1MHz, 106.

2、1MHz and 107.9MHz. 4. RF levels are open circuit voltages of signal generator with 75 ohms output impedance. B. OSCILLATOR TUNING VOLTAGE 1. Connect DVM between FE1 No. 5 PIN and ground. 2. Tune to 87.5MHz and check DVM for reading of 3Vdc +/-0.5Vdc 3. Tune to 107.9MHz and check DVM for reading of 2

3、0.5Vdc +/-0.5Vdc. If either of the above is out of tolerance, adjust FE1 (oscillator coil L101) until both readings are within tolerance. C. I.F. 1. Connect DVM between TP2 and TP3. 2. Apply 98.1MHz (60dBu) to FM antenna input and tune to 98.1MHz. 3. Adjust IFT1 (FM IF) for 0Vdc +/-50mV reading on D

4、VM. 4. Adjust IFT2 (FM IF) until minimum THD is achieved at audio output. 5. Repeat (3) and (4) until no further improvement can be made. D. FRONT-END I.F. 1. Apply 98.1MHz (12dBu) to antenna input and tune to 98.1MHz. 2. Carefully adjust FE1 IFT until minimum THD is achieved at audio output. E. R.F

5、. 1. Apply 98.1MHz (7dBu) to antenna input and tune to 98.1MHz. 2. Check if THD is better than 3%. If not, proceed to (3). 3. Adjust FRONT-END COILS (L102 - L104) by squeezing or stretching using a non-metallic tool until THD is better than 3%. 4. Check THD at 90.1MHz and 106.1MHz with 8dBu input. I

6、f THD is more than 3% for both frequencies, re-adjust until required THD is met. F. AUTOSEARCH AND FM STEREO LEVEL 1. Turn VR2 fully clockwise. 2. Set stereo modulator to L=R mode and 98.1MHz (32dB) to antenna input. 3. Adjust VR2 clockwise until “S” light up in the LCD. RadioFans.CN 收音机爱 好者资料库4. Ch

7、eck if auto-search operation is working properly at antenna input level of 28dB. G. CENTER TUNER LED 1. Turn VR1 fully clockwise. 2. Set stereo modulator to MONO mode and 98.1MHz (26dB) to antenna input. 3. Adjust VR2 clockwise until “I” display in the LCD. H. STEREO SEPARATION AND PILOT SUPPRESSION

8、 1. Modulate L- only at 98.1MHz (68dBu) and adjust VR3 for minimum output on right channel. 2. Modulate R- only and adjust VR3 for minimum output on left channel. 3. Repeat (1) and (2) until readings are the same and within specification (45dB). 4. Turn off modulating signal but leave pilot tone. 5.

9、 Adjust FL6 and FL7 for minimum output on left and right channels, respectively. AM SECTION A. PREPARATION 1. Set signal generator to AM mode with 1KHz at 30% modulation. 2. Connect 22pF ceramic capacitor between signal generator and AM antenna input terminal input; the capacitor should be as close

10、as possible to antenna input terminal. 3. Store the following frequencies: 600KHz, 1000KHz and 1400KHz. B. OSCILLATOR TUNING VOLTAGE 1. Connect DVM between TP4 and TP5 (Ground). 2. Tune to 600KHz and adjust L4 (AM OSC) for 1.75Vdc +/-50mV reading on DVM. C. I.F. 1. Apply 1000KHz (45dBu) to antenna i

11、nput. 2. Tune to 1000KHz and adjust IFT3 (AM IFT) for maximum reading on audio output. D. R.F. 1. Apply 600KHz (45dBu) to antenna input. 2. Tune to 600KHz and adjust L3 (AM ANT) for maximum reading on audio output. 3. Apply 1400KHz (45dBu) to antenna input. 4. Tune to 1400KHz and adjust C26 (VC TRIM

12、) for maximum reading on audio output. 5. Repeat (1) to (4) until no further improvement can be made. ITEM PART NUMBERLOCATIONQTY1 90-1742-2MODULE, TUNER MAIN PCBXT12 29R-1236-220L5.6.INDUCTOR 22uH 10% SMD 121023 29R-1236-2R2L1.INDUCTOR 2u2H 10% SMD 121014 29R-1236-680L2.INDUCTOR 68uH 10% SMD 121015

13、 30R-LC72131MIC4.IC FREQ SYNTHESIZER LC72131MMFP20 RoHS SANYO16 30R-MMBD4148D5.6.8.12.13.14DIODE SWITCHING MMBD4148/914DIODE 0.2A/75V SOT-2367 30R-MMBT4401LT1Q1.10.11.12.14.15.19.20.26.TR NPN MMBT4401LT1ON 0.6A/40V SOT-2398 30R-MMBT4403LT1Q9.13.25TR PNP MMBT4403LT1ON 0.6A/40V SOT-2339 30R-M4D9.10.11

14、RECTIFIER DIODE M41A 400V SMA WILLAS310 30R-AT32L-8AUIC9.IC ATMEGA32L-8AU 8-BIT AVR8K FLASH TQFP 44A 111 30R-2SC1815GRQ2.3.TR NPN 2SC1815GR TAP TOSHIBA212 30R-2SC829CQ4.5.6.7.8.TR NPN 2SC829C TO-92 TAP513 30R-J112Q16.17.18.TR JFET N-ch J112 35V 350mWXT TO-92 ON/FAIRCHILD314 17R-2019C26.VC TRIM 30PF

15、TZ03R300FR 115 16R-1AN121JR97.RES MO 120R 5% 1W RSF1 MK 116 29R-R6V104BVR2.3.SEMI-FIX VR 100KB RH0615C15J217 30R-4020X1.CER-RESONATOR CSB456F11 118 30R-4017-1X2.CRYSTAL QUARTZ 7.2MHz HC-49US119 15R-3010*AFEI.FRONT END KST-F724HA-1 120 17R-2016-1FL4.CERAMIC FILTER SFZ450B 121 17R-2017FL5.EMI FILTER S

16、-174-077 122 17R-2027FL1.2.CERAMIC FILTER 10.7MHz REDMURATA SFELF10M7FA00-B0323 29R-1224IFT2.FM IFT TWS-384-0428(4400) 124 29R-1225IFT3.AM IFT TWS-384-0425(5200) 125 29R-1226IFT1.FM IFT TWS-384-0427(4300) 126 29R-1228FL6.7.MPX FILTER S-174-084 10DFEE01227 29R-1230L3.AM RF TWS-384-426 (M-10BLN)TUNER

17、SERIES SUMIDA128 29R-1231L4.AM OSC TWS-384-424 129 30R-1N60*AD1.2.DIODE 1N60 (RED) 230 30R-LA1266IC1.IC LA1266 (AM/FM IF) 131 30R-LA3401IC2.IC LA3401 (FM MPX) 132 30R-M51951BIC6.IC RESET M51951BSL MITSUBISHI133 30R-SVC321SPAD3.4.DIODE SVC321SPA(A) 234 12R-2154-1J7.JACK RCA 2P SEMI GOLD PLATEDDTR-020

18、2G-004-1135 12R-2240J1.ANT TERMINAL AJ-2019-040 USXT 136 17R-2.5EF228MC89.90CAP EL 2200uF/25V 20% HTC5 13x21mm237 17R-2023-1FL4.BAND PASS FILTER LPF88A 138 30R-HIN232CPIC5.IC RS232 DRIVER/RECEIVERHIN232CP DIP16 RoHS XT139 30R-LM7805AIC9.IC POSITIVE VOL.REG.LM7805(F)ANS/JRC/ST/IR/ON 1A/5V TO-220140 3

19、0R-LM7812AIC10.IC POSITIVE VOL.REG.LM7812(F)ANS/JRC/ST/IR/ON 1A/12V TO-220141 30R-LM7912AIC11.IC NEGATIVE VOL.REG.LM7912(F)ANS/JRC/ST/IR/ON 1A/-12V TO-220142 30R-MPS6724Q21.TRANSISTOR MPS6724 143 30R-RB154BD1.DIODE BRIDGE RB154 1.5A/400V144 31R-1383SW2.SWITCH SLIDE SKV-22D21-G6-TA2P2T L=6mm 145 31R-

20、1383-1SW1.SWITCH SLIDE SKV-24D02-G6-NA2P4T L=6mm XT146 35R-3046RL1.RELAY DPST 12V UL/CSA/VDEVB-12MBU-5 TAKAMISAWA147 90-1798MODULE, TUNER DISPLAY XT148 19R-1798PCB FR4 D-S DISPLAY XT149 30R-MMBD4148D1.2.3.4.5.DIODE SWITCHING MMBD4148/914MZC&M DIODE 0.2A/75V SOT-23550 30R-SAA6588TU100.IC RDS PRE-PROC

21、ESSOR SAA6588TSO20 PHILIPS 151 30R-PT2222-001U101.IC RC TRANSMITTER PT2222-001SOP24 PRINCETON152 29R-1242L1.FERRITE BEAD 1.0A 0805 ACM201209A600153 30R-2SD1781KRQ1.TR NPN 2SD1781KR SOT-23 154 30R-M4D15.RECTIFIER DIODE M4MZC-66 1A 400V SMA WILLAS155 30R-MIR053LED1.DIODE INFRARED EMITTINGMIR053 XT156

22、30R-4028-1X1.CRYSTAL 4.332MHz HC-49US 157 30R-4029X2.RESONATOR CSB455EB MURATA158 30R-1156*BLCD1.LCD MODULE C1624MWLJ1 16x2ECOMAG w85xh30 xd13.2mm159 30-PIC-26043TH2IR1.RECEIVER IR T7a PIC-26043TH2160 31R-1365 S41-52.55.56.33.60.TACT SW SKHHBV2710-EK 7mm 661 31R-1375TIME/TEXT/PROGRAM/TYPE. SWITCH TA

23、CT 4.5x6.5mm L=17mmKA-170 RoHS TECX462 12R-2239-1J3.J4.JACK DC POWER 2.5mm DJ-0702B-025 JYE TAI263 31R-1383SW3.SWITCH SLIDE SKV-22D21-G6-TA2P2T L=6mm 164 90-1801MODULE, POWER SUPPLY XT165 19R-1801PCB FR4 D-S POWER SUPPLY RoHSXT166 31R-1250SWITCH PUSH NON-LOCK 1P RoHSXT/AV81HT1XT SERVICE PART LIST -

24、EC, BLACKPART DESCRIPTION67 XT-B-COMCOMMON PARTSXT168 11R-8644*APANEL REAR RoHSXT169 11R-8633B-2PANEL FRONT BLACKXT w430 xh72xd23mm170 11R-6425-1CHASSIS FRONT RoHSXT 420 x57.2x13.5mm171 11R-6436CHASSIS MAIN RoHSXT172 13-1063WINDOW DISPLAY XT173 11R-1123-1COVER TOP BLK RoHSAMC174 12-1083POWER LINK175

25、 12R-1120 SHAFT BUTTON 676 12R-2177ANT FM 300 ohm T TYPE177 12R-2178ANT FM BALUN AJ-2010 A175 ohm 300 ohm178 12R-2116*BAC INLET 3P W/FUSE HOLDER SC-8F-21C 10A/250V SWEETA179 12R-3110 KNOB PUSH BLK 680 12R-3152GNPOWER SW BUTTON GREEN AMC181 13R-8227BPOWER KNOB BUSHION AMC182 28R-1046-1BFOOT (R) H=17m

26、m BLK AMC283 28R-1046-2BFOOT (L) H=17mm BLK AMC284 29R-2185*B-UNTRANSFORMER POWER XT185 29R-3071RF CORE FILTER 186 30R-1148LED 3mm BLUE M034BLD GAN/SIC 430nM PD=100mW VF=3.5V187 31R-1376SWITCH SLIDE 115/230V EV-12-2 DPDT UL/VDE188 21R-2622-1*AMANUAL INSTRUCTION RS232189 XT-B-ECEC VER PARTS 230V190 1

27、4R-5030*APOWER CORD EC 3P 1.83M BLKEL211+EL701 H05VV-F 0.75/3C191 CTR-5264CARTON INNER RoHSAMC w494xd361xh143mm192 CTR-5265CARTON OUTER RoHSAMC w506xd373xh664mm0.2593 R32S1250500TUSFUSE UTE T500mA/250V RoHST-LAG (UL/CSA/VDE) 5x20mm294 R32S12502K0TUSPFUSE UTE T2A/250V RoHST-LAG (UL/CSA/VDE/PSE) 5x20m

28、m1PART NUMBERXT-B_ECXT-B_A1XT-S_EC11-1123S-111R-1123-111-11R-8633B-211-11R-8633S-2-112-3122S-1612R-3097S-112R-31101616-12R-3152GN11-14R-5030*A1-114R-5107*B-1-15R-2090B44-15R-2090S-416R-1:2CA275J-1-21-30243-321R-2315-1-21R-2331-A1-1-21R-2331-EC1-121R-2332-A1-0.5-21R-2332-EC0.5-0.521R-24401-121R-3015-1-1-XT DIFFERENT VERSION PART LIST