NAD-90-int-sch维修电路原理图.pdf

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1、I w 0 w LU I RadioFans.CN 收音机爱 好者资料库 2.BIASADJUSTMENT PROCEDURE Theproperbiasadjustmentismostimportanttoassurecorrectperformanceoftheamplifier.Bias adjustmentisnecessaryifanyofthetransistorsarereplacedinthepower amplifiercircuitryorthe amplifierexhibitsoverheatingoftheoutputtransistorsundernormalope

2、ratingcondisions. INDICATORADJUSTMENTREMARKS -:-.-. -.-t- Adjustfor0.0060.015Vacross DCVoltmeterVR6O1a,b(1Kohm) - R624a,b(0.33ohm)withNOSIGNAL REMARK:Biascanalsobeadjustedbyusingalinewattmeter.AdjusttheVR6O1aandVR6O1b to thepointatwhichthelinewattmetershowsveryslightincrease. 3.ADJUSTMENTAND CHECK P

3、OINTS R624b R624a VB601b vH60 RadioFans.CN 收音机爱 好者资料库 7.0027PRE-AMPBOARD (TOPVIEW) (D o 0; 0co) II9) n 100 ; .9) 4E) -zSo. t0o (IOO I _zco_ ogo 00 609). Go q,) Q - (); 0. q qLO EDCL P06) :q -SO6) :z z C- 4 Q RadioFans.CN 收音机爱 好者资料库 9.0028MAINAMPBOARD(TOP VIEW) C C I, -J U, I RadioFans.CN 收音机爱 好者资料库

4、Transistors. Powerboard : TR601a A640 BC560 TR601b A640 BC560 TR 602b BC560 hfe 498 TR 602a BC560 hfe 498 TR 604b 2SC3328 (y) hfe 144 TR 604a 2SC3328 hfe 144 TR 605b C945 hfe 242 TR 605a C945 hfe 246 TR 606b A733 hfe 338 new TR 606a A733 hfe 338 new TR 607b BD 139 hfe 110 TR 607a BD 139 hfe 110 TR 6

5、08b BD140 hfe 117 TR 608a BD 140 hfe 117 TR 901b BC550 hfe 580 new TR 901a BC550 hfe 580 new TR 902b BC550 hfe 594 new TR 902a BC550 hfe 594 new Tone control board TR 501a BC 560 Hfe 542 new. TR 501b BC 560 Hfe 546 new TR 502a C1570 (G) Hfe 339 TR 502b C1570 (G ) Hfe 339 TR 503a BC550 Hfe 651 new TR

6、 503b BC550 Hfe 651 new TR 504 BC560 Hfe 547 new TR 505 BC550 Hfe 607 new TR 506 BC550 Hfe 607 new TR 801 2SA684 hfe 200 TR 802 2SC1384 hfe 200 C1570 =BC 550 A640 = BC 560 A841 = BC 560 A733 = BC 557 C945 = BC 182 RadioFans.CN 收音机爱 好者资料库 Ceramic caps. Tone board. C514 = 154k =150000 pf = 150nF = 0,1

7、5 uF = MKT 0,15 C503b = 562k = 5600pf = 5,6nF C503a = 562k = 5600pf = 5,6nF newtone C519 = 47pf C506b = 47pf C506a = 47pf C502a = 182k = 1800 pf =1,8nf C503b = 182k = 1800pf = 1,8nf C505a = ,001k = 0,001uf = 1 nf newtone C505b = ,001k = 0,001uF = 1nf c518 = .001k =0,001uf = 1nf C516 = 220pf newtone

8、c 512a= 560 = 560pf c512b = 560 = 560pf c513a = 563k = 56000 pf = 56nf ebay 2,50 c513b = 56nf0= 56000pf = 56nf C526a = .0068 = 0.0068uf = 68nf C526b = .0068 = 0.0068uf = 68nf powerboard : C608b = 100pf c 608a = 100pf c904a = 333k 33000pf = 33nf c 904b = 333k 33000pf = 33nf c909b = 47 pf c909a = 47 p

9、f c 905 a= 333k 33000pf = 33nf c905 b = 3335 33000pf = 33nf c 903a =,0027k 0,0027 uf = 2,7 nf c903b = ,0027k 0.0027uf = 2,7nf c601a = 220pf c 601b = 220pf c607a = 22pf-*+ c607b = 22pf c611a = 220pf c611b = 220pf c808-811 = ,01uF 4x = 10nF RadioFans.CN 收音机爱 好者资料库 r t I czu,_ i -L i:Lr L. _ _ + T 71 m

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