NAD-C425-tun-sm 维修电路原理图.pdf
《NAD-C425-tun-sm 维修电路原理图.pdf》由会员分享,可在线阅读,更多相关《NAD-C425-tun-sm 维修电路原理图.pdf(32页珍藏版)》请在收音机爱好者资料库上搜索。
1、NADC 425STEREOAM/FM TUNERC 425STEREOAM/FM TUNERSERVICE MANUALRadioFans.CN 收音机爱 好者资料库- 2 - 3 -SERVICE SAFETY PRECAUTIONS1. Safety check out(Only U.S.A. model)Before returning the product to the customer, make leakage current or resistance measurements to determine that exposed parts are acceptably in
2、sulated from the supply circuit.Parts marked with the symbol are critical with regard to the risk of fire and electric shock.Replace only with parts recommended by the manufacturer.CONTENTSDESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3、 . . . . . . . . . PAGESPECIFICATIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3REAR PANEL / FRONT PANEL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4DISASSEMBLY IN
4、STRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5BLOCK DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6WIRING DIAGRAM. . . . . . . . . . . . . . . . . . . . .
5、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7ADJUSTMENT POINTS DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8INSTRUMENT SETUP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6、. . . . . . . . . . . . . . . . 9ALIGNMENT PROCEDURES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10PCB LAYOUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-12SCHEMAT
7、IC DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-14IC BLOCK DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-18ELECTRICAL PARTS LIST. . . . . . . . . . . . . . .
8、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-27EXPLODED VIEW. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28EXPLODED VIEW PARTS LIST. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9、 . . . . . . . . . . . . . 29-30PACKING DIAGRAM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31RadioFans.CN 收音机爱 好者资料库- 2 - 3 -SPECIFICATIONSAM TUNER SECTIONInput level is expressed as the reading in open-circuit of 75-ohm source
10、impedance signal generatorUsable Sensitivity (999/1000kHz) 30dBS/N Ratio (5mV in) 38dBTHD (5mV in) 3%IF Rejection (450kHz) 36dBImage Rejection (F+2xIF) 28dBSelectivity 17dBOutput 130 +/-20mVLoop Sensitivity (20dB S/N) 999/1000 kHz 66 dB 603/600 kHz 66 dB 1404/1400 kHz 66 dBFrequency response (100 -
11、2.3 kHz, 5mV) 6 dBFM TUNER SECTION *C *AHInput level is expressed as the reading in open-circuit of 75-ohm source impedance signal generatorUsable Sensitivity (98 MHz) 13 dB 13 dBSignal / Noise Ratio Mono 72 dB 72 dB (60 dB, IHF wtd) Stereo 66 dB 66 dBFrequency Response (20 Hz - 15 kHz, 60 dB) 01.0
12、dB 01.0 dBChannel Separation (60 dB) 30 Hz 33 dB 33 dB 1 kHz 42 dB 42 dB 10 kHz 32 dB 32 dBAlternate Channel Sensitivity (40 dB, 400 kHz) 60 dB 45 dBCapture Ratio (40 dB) 3 dB 3 dBAM Suppression (60 dB, 100% Mod.FM, 30% Mod AM) 65 dB 65 dBImage Rejection (119.4 MHz) 85 dB 85 dBI.F. Rejection (10.7 M
13、Hz) 78 dB 78 dBPilot Suppression (60 dB) 60 dB 60 dBTHD (60 dB, L=R 75 kHz for AH, 40 kHz Dev for C) Mono 0.25% 0.25% Stereo 0.35% 0.35%Auto-Search sensitivity On 24 dB 24 dB Off 15 dB 15 dBRDS Decode Sensitivity 26 dB 26 dBPHYSICAL SPECIFICATIONSDimensions (Width x Height x Depth) 435 x 80 x 285 mm
14、Net weight 4 kg (8.8 lbs)Shipping weight 5.1 kg (11.22 lbs)- 4 - 5 -REAR PANEL / FRONT PANEL1. FM ANTENNA2. AM ANTENNA3. OUTPUT4. IR IN5. 12V TRIGGER IN6. AC LINE CORD7. RS-2321. POWER ON / OFF2. POWER STATUS INDICATOR3. BLEND4. MEMORY5. FM MUTE / MODE6. AM / FM7. DISPLAY8. PRESET / TUNE9. DISPLAY A
15、REA10. PRESET / TUNE CONTROLFRONT PANELREAR PANELIMPORTANT NOTES1. Show the software version Press “BLEND” and “AM/FM”.2. Light UP all the icon on the VFD Press “BLEND” & “DISPLAY”.3. Factory test resets When VFD all Light press any key.4. AM Step 10K/9K Change When AM band, press “AM/FM” & “PRESET/
16、TUNE”.5. Shipment resets When pressing “DISPLAY” & “PRESET/TUNE” to VFD all Light, press any key.- 4 - 5 -54312766DISASSEMBLY INSTRUCTIONS1. Remove machine screws M 4.0 x 6.0 ( 1 to 4 ) from the side panels. Remove tapping screw 3.0 x 8.5 5 from the back panel. Refer to Figure No.1. Figure No.12. Pu
17、ll both sides of the TOP COVER slightly outwards 6 and tilt approx. 35 and then remove in the direction as indicated by the arrow 7 . Refer to Figure No.2. Figure No.2.- 6 - 7 -AM LOOP ANTFM ANTOUTPUTFRONT ENDENV172D3G1VFDCPULC866448BU201U202VFD DRIVERPT6311KEY MATRIXTrigger INU203EEPROM24C08PLLLC72
18、723MRDS DECODERU901AM/FM IFLA1837MUTINGIR INU70174HC86M218REMOTESENSORPOWERSUPPLYVFD-VP+5V CPU+10VAC INPUTLRVTVTcedataclkRDS-CLKRDS-SIGRDS-DATAMPXINdataout(#1)=Power On(#1)+(#2)=StandbyLC7218U903ST/MO, MUTE, SMETERTUNEFMOSC/IFAMOSC/IF127171623230U902212345151115810 IN16142016142212/1351619241918BLOC
19、K DIAGRAM- 6 - 7 -WIRING DIAGRAMMAIN BOARDKEY BOARDDISPLAY BOARDLED BOARDTRANSFORMERPOWER SUPPLY BOARDYELLOWBLUEWHITE- 8 - 9 -ADJUSTMENT POINTS DIAGRAMOSCRFVT- 8 - 9 -FMSIGNALGENERATORANTENNATERMINALOUTPUTTERMINALDISTORTIONMETERDISTORTIONMETERACVOLTMETEROSCILLOSCOPEACVOLTMETEROROSCILLOSCOPEACVOLTMET
20、EROROSCILLOSCOPEOUTPUTTERMINALOUTPUTTERMINALLRANTENNATERMINALANTENNATERMINALANTENNATERMINALAM LOOPANTENNA(Accessory)AM LOOPANTENNA60cmDIGITALMILLIVOLT-METERVT_J911FMSIGNALGENERATORAMSIGNALGENERATORFMSIGNALGENERATORRDSGENERATORFMSTEREOGENERATORP901OUTPUTTERMINALDCMILLIVOLT-METERUNITUNITUNITUNITINSTRU
21、MENT SETUP1. FM MEASUREMENTFig. 1Fig. 22. RDS MEASUREMENTFig. 33. AM MEASUREMENTFig. 4- 10 -ALIGNMENT PROCEDURESFM/RDS SECTION- FM mono: 1kHz, 75kHz devi., 60dB/V- FM stereo: 1kHz, 67.5kHz devi., 60dB/V Pilot signal 19kHz 7.5kHz devi.OUTPUTS- Connect the 47Kohm resistor unless otherwise noted.ItemSt
22、epConnectionof instrumentFM SGoutputStereo modulator outputTuningfrequencyOutputindicatorAdjustmentpointAdjustforRemarksFMIF/RF1Fig.199.0MHz1kHz 75kHz devi.65dBf (60dB)99.0MHzDC voltmeterL941070mVFM MUTE/MODE switch: ON/AUTORepeat the steps1 to 3 until no further adjustment is necessary.2AC voltmete
23、rIFT on the front endMaximum3DistortionanalyzerL942MinimumStereoDistortionFig.299.0MHz Ext.mod. 65dBf (60dB)Channel Lor R 1kHz99.0MHzDistortionanalyzerIFT on the front endMinimumFM MUTE/MODE switch: ON/AUTODont turn more than 180StereoSeparationFig.299.0MHz Ext.mod. 65dBf (60dB)Channel Lor R 1kHz99.
24、0MHzOscilloscopeR941MaximumseparationRepeat stereo distortion and stereo separation alignment until THD at minimum and separation at maximum.DistortionMeterMinimumMuteLevelFig.199.0MHz 18dB99.0MHzOscilloscopeR956SignaloutputRDSFig.399.0MHz Ext.mod. 65dBf (60dB)RDS 2% MOD99.0MHzDecodethe RDS-Program
25、stationAM SECTIONAF Modulation: 400Hz, 30%For AH VersionStepAM SGoutputTuningfrequencyOutputindicatorAdjustmentpointAdjustfor1530kHzDigitalDCvoltmeterOSC coilon RFblock M9711.350.2V2600kHz400Hz 30% mod.60dB/m600kHzACvoltmeterRF coilon RFblock M971Maximum3600kHz400Hz 30% mod.60dB/m990kHzACvoltmeterL9
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- NAD-C425-tun-sm 维修电路原理图 NAD C425 tun sm 维修 电路 原理图