NAD-C426-tun-sm 维修电路原理图.pdf
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1、NADC 426STEREOAM/FM TUNERC 426STEREOAM/FM TUNERSERVICE MANUALRadioFans.CN 收音机爱 好者资料库- 2 -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 insula
2、ted 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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-4REAR PANEL / FRONT PANEL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5DISASSEMBLY INSTRU
4、CTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6BLOCK DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7WIRING DIAGRAM . . . . . . . . . . . . . . . . . . . . . .
5、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8ADJUSTMENT POINTS DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9INSTRUMENT SETUP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6、 . . . . . . . . . . . . . 10ALIGNMENT PROCEDURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11PCB LAYOUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12-14SCHEMATI
7、C DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15-17IC BLOCK DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18-22ELECTRICAL PARTS LIST . . . . . . . . . . . . . .
8、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23-31EXPLODED VIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32EXPLODED VIEW PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9、. . . . . . . . . . . . . . . . . . . 33PACKING DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34RadioFans.CN 收音机爱 好者资料库- 3 -SPECIFICATIONSAM BAND SPECIFICATIONFrequency Range CA 530 - 1710 KHz Step 10 KHz EU 531 - 1602 KHz
10、 Step 9 KHz FREQ (KHz) UNIT LIMIT1. Usable sensitivity 999 dBuV = 38 (5mV input) /10003. THD (5mV input) 999 % = 36 (ref. to item 8) /6005. Image Rejection (F+2xIF) 1404 dB = 25 (ref. to item 8) /14006. Selectivity 999 dB = 17 (ref. to item 8) /10007. Output 999 mV 100 180 (30%, 10mV) /10008. Loop s
11、ensitivity 20dB S/N 999/1000 dB = 68 603 / 600 dB = 68 1404 / 1400 dB = 689. Frequency response 100 - 2.3KHz 999 /1000 dB 0 +/- 6dB (400 Hz, 5mV)FM BAND SPECIFICATIONFrequency Range CA/EU 87.5 - 108MHz Step 50 KHz FREQ UNIT LIMIT1. Usable sensitivity MONO 98MHz dBu = 72 (60dBu A filter) STEREO 98MHz
12、 dB = 683. THD (60dBu Audio LPF) MONO 98MHz % 0.4 (60dBu Audio LPF) STEREO 98MHz % 80 (refer to item 1)5. Image Rejection (119.4 MHz) CA&EU 98MHz dB = 70 (refer to item 1)- 4 -6. Capture ratio (40dBu) dB 60 60dBu 100% mod FM, 30% mod AM8. Pilot suppression L & R 98 MHz dB 609. Frequency response 20H
13、z & 10KHz dB 0 +/- 1.5 ( 1KHz Ref ) UL 75Us,CE50Us10. Channel Separation 30 Hz dB = 28 (60dBu IHF wtd) 1 KHz dB = 38 10KHz dB = 2811. Alternate channel selectivity +/-400KHz, IHF UL dB = 35 CE dB 6012. Muting level dBu 18 +/-6.13. Output CA 98MHz mV 350600 EU 55090014. RDS decode sensitivity. dBu =
14、3015. Auto-search sensitivity ON dBu = 1516. Blend ON separation1KHz 98MHz dB 6 +/-2- 5 -REAR PANEL / FRONT PANEL1. FM ANTENNA TERMINAL2. AM ANTENNA TERMINAL3. OUTPUT (L, R)4. RS-2325. IR IN6. +12V TRIGGER IN7. AC MAINS INPUT1. STANDBY LED2. STANDBY BUTTON3. FM/AM4. FM MUTE/MODE5. BLEND6. DISPLAY7.
15、MEMORY8. PRESET/TUNE9. REMOTE SENSOR10. VFD11. PRESET/TUNE CONTROL KNOB:1234567891011FRONT PANEL1432567REAR PANELIMPORTANT NOTES1. Show the software version Press “DISPLAY” and “FM/AM” .2. Light UP all the icon on the VFD Press “FM/AM” & “PRESET/TUNE” .3. Factory test resets When VFD all Light press
16、 any key.4. AM Step 10K/9K Change When AM band, press “FM MUTE/MODE” & “PRESET/TUNE” .5. Shipment resets (clear) When pressing “MEMORY” & “PRESET/TUNE” to VFD all Light, press any key.- 6 -54312766DISASSEMBLY INSTRUCTIONS1. Remove machine screws M 4.0 x 6.0 ( 1 to 4 ) from the side panels. Remove ta
17、pping screw 3.0 x 8.5 5 from the back panel. Refer to Figure No.1. Figure No.12. Pull 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.- 7 -BLOCK DIAGRAMAM LOOP ANTFM ANTOUTPUTFRONT EN
18、DENV172D3G1VFDCPUP89LPC936U201U202VFD DRIVERPT6311KEY MATRIXTrigger INU203EEPROM24C08PLLLC72723MRDS DECODERU901AM/FM IFLA1837MUTINGIR INU70174HC86STANDBYPOWERSUPPLYRS232M218REMOTESENSORPOWERSUPPLYVFDSTANDBY 3V3-VP+5V CPU+10VAC INPUTRELAYLRVTVTcedataclkRDS-CLKRDS-SIGRDS-DATAMPXINdataout(#1)=Power On(
19、#2)=StandbyLC7218U903ST/MO, MUTE, SMETERTUNEFMOSC/IFAMOSC/IF127171623230U902212345151115810 IN16142016142212/1351619241918- 8 -WIRING DIAGRAMTRANSFORMERMAIN boardDSP boardPSU boardLED boardKEY boardYELLOWBLUEWHITE7013-0490+0- 9 -ADJUSTMENT POINTS DIAGRAMOSCRFVT- 10 -FMSIGNALGENERATORANTENNATERMINALO
20、UTPUTTERMINALDISTORTIONMETERDISTORTIONMETERACVOLTMETEROSCILLOSCOPEACVOLTMETEROROSCILLOSCOPEACVOLTMETEROROSCILLOSCOPEOUTPUTTERMINALOUTPUTTERMINALLRANTENNATERMINALANTENNATERMINALANTENNATERMINALAM LOOPANTENNA(Accessory)AM LOOPANTENNA60cmDIGITALMILLIVOLT-METERVT_J911FMSIGNALGENERATORAMSIGNALGENERATORFMS
21、IGNALGENERATORRDSGENERATORFMSTEREOGENERATORP901OUTPUTTERMINALDCMILLIVOLT-METERUNITUNITUNITUNITINSTRUMENT SETUP1. FM MEASUREMENTFig. 1Fig. 22. RDS MEASUREMENTFig. 33. AM MEASUREMENTFig. 4- 11 -ALIGNMENT PROCEDURESFM/RDS SECTION- FM mono: 1kHz, 75kHz devi., 60dB/V- FM stereo: 1kHz, 67.5kHz devi., 60dB
22、/V Pilot signal 19kHz 7.5kHz devi.OUTPUTS- Connect the 47Kohm resistor unless otherwise noted.ItemStepConnectionof instrumentFM SGoutputStereo modulator outputTuningfrequencyOutputindicatorAdjustmentpointAdjustforRemarksFMIF/RF1Fig.199.0MHz1kHz 75kHz devi.65dBf (60dB)99.0MHzDC voltmeterL941070mVFM M
23、UTE/MODE switch: ON/AUTORepeat the steps1 to 3 until no further adjustment is necessary.2AC voltmeterIFT on the front endMaximum3DistortionanalyzerL942MinimumStereoDistortionFig.299.0MHz Ext.mod. 65dBf (60dB)Channel Lor R 1kHz99.0MHzDistortionanalyzerIFT on the front endMinimumFM MUTE/MODE switch: O
24、N/AUTODon t turn more than 180StereoSeparationFig.299.0MHz Ext.mod. 65dBf (60dB)Channel Lor R 1kHz99.0MHzOscilloscopeR941MaximumseparationRepeat stereo distortion and stereo separation alignment until THD at minimum and separation at maximum.DistortionMeterMinimumMuteLevelFig.199.0MHz 18dB99.0MHzOsc
25、illoscopeR956SignaloutputRDSFig.399.0MHz Ext.mod. 65dBf (60dB)RDS 2% MOD99.0MHzDecodethe RDS-Program stationAM SECTIONAF Modulation: 400Hz, 30%For AH VersionStepAM SGoutputTuningfrequencyOutputindicatorAdjustmentpointAdjustfor1530kHzDigitalDCvoltmeterOSC coilon RFblock M9711.350.2V2600kHz400Hz 30% m
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- NAD-C426-tun-sm 维修电路原理图 NAD C426 tun sm 维修 电路 原理图