Realistic-31_2077-rec-sm 电路图 维修手册.pdf
《Realistic-31_2077-rec-sm 电路图 维修手册.pdf》由会员分享,可在线阅读,更多相关《Realistic-31_2077-rec-sm 电路图 维修手册.pdf(40页珍藏版)》请在收音机爱好者资料库上搜索。
1、ruLtsfiC Serulce STA.78 AM /FM STEREO Catalog Number : RECEIVER 31-2077 cusToM MANUFACTURED FoB RADIo sHACK In DMSIoN 0F TANDv conponAloN RadioFans.CN 收音机爱 好者资料库 (1) (21 (3) (4) (5) (6) (71 (B) (e) ( 10) (11) (121 ( 13) (141 ( 15) ( 16) (171 ( 1B) ( 1e) (20) (211 CONTENTS ELECTRICAL PERFORMANCE SPEC
2、I FICATIONS DISASSEMBLY INSTRUCTIONS . PAGE 3-5 BLOCK DIAGRAM DIAL STRINGING LEVEL DIAGRAM ALIGNMENT INSTRUCTIONS TROUBLESHOOTI NG BRIEF DESCRIPTION OF PROTECTOR CIRCUIT IC all units should be able to approximate these - some will exceed and some may drop slightly below these specs. Limit Specs repr
3、esent the absolute worst condition which still might be considered acceptable; in no case should a unit perform to less than within any Limit Spec. 2. DISASSEMBLY INSTRUCTIONS 1) To remove Chassis f rom wooden cabinet. Turn the cabinet upside down and re- move the six screws from the bottom cabinet.
4、 (Figure A) 2) Removal of Front Panel. a) Remove the chassis from wooden b) Pull out the Main Chassis. c) Remove the two screws from the top d) Remove knobs and pull off panel. FigureA cabinet as described in 1). and three screws from the bottom of (F igure B1 , B2l the Front Panel. 3)To remove Rear
5、 Panel from chassis. Remove the four screws from the Rear Panel. (F igure C) Figure B1Figure 82 -5- a E U Y U II a .I ri -;- 1 E 5 9 t! i -N I I O _.1 a u a Eo =o oi doo ll 9 3 e- d LF ,E;- o? 50 i ij* i :33 or;l -o EE i oo z ! E;I =Pg 66 =N =E =o EE = EF 3. BLOCK DIAGRAM -6- 4. DIAL STRINGING DIAGR
6、AM *START WITH CAPACITOR SET AT MINIMUM. PLATES FULLY OPEN (UNMESHED). *Pointer Position : HIGH END 5. LEVEL DIAGRAM F I AUDIO FREQIJENCY. lkHz -7- 6.ALIGNMENT INSTRUCTIONS AUDIO CIRCUIT ADJUSTMENT,/CHECK EOUIPMENT REOUIRED 1. DC Voltmeter 2. Audio Oscillator 3. Oscilloscope 4. AC Voltmeter Note: Ma
7、intain voltage at 12O volts AC, 60 Hz (UL, CSA) (240 volts, 50 Hz AC for Australian models). *Set SELECTOR Switch to AUX. *Set MODE Switch to STEREO. See P.C.B. illustration for alignment points/adjustments. For location of connection points and trimmer resistors, see P.C.B. view. (-25mV to+25mV) Fi
8、gure 6 Oscilloscoge (Shorled OutpuiCondition) (Normol Condiiion) Figure 5 MAIN AMP ADJUSTMENT STEPADJUSTMENTEOUIPMENT CONNECTIONAUDIO FBEO. LEVELADJUSTMENT 1 Check Balance by measuring DC voltage across Output Termi- nal of L and R chan- nel. DC Volt Meter See Figure 1No signalDC voltage should be l
9、ess than 25 mV 2 ldling current adjust- ment DC Volt Meter See Figure 2.No signalAdjust so voltage across Emitter resistors R633 anc R634 is 5 mV (8 ohm load). VR601 VR602 Figure CHECKING LIMITER CIRCUIT STEPADJUSTMENTEOUIPMENTCONNECTIONAUDIO FREOSETTING LEVEL 1 Audio Osc. V.T.V.M. Oscilloscope See
10、Figure 3.1000 HzVOLUME: Max. BASS, TREBLE BALANCE: center Adjust input to AUX to get out- put level at just the clipping point (4 ohm load) Figure 4. 2 Check the limiter ci rcu i t. Audio Osc. V.T.V.M. Oscilloscope See Figures 3, 5. 1000 HzSame as aboveCheck that output dropt to a square wave across
11、 R633 (R634) when out- put speaker termi- nals are shorted. See Figure 6. 4ohm L.od ,A-. -(yo c - +) AUDIO Osc. AUX SrA-79 ( rooHz) Figure 3 Oscilloscope 1J -8- AM RF I ti6 6d De , - | 6G_=_j r2or STEP SIGNAL GENERATOR COUPLING SIGNAL GENERATOR FREOUENCY DIAL SETTlNG INDICATORADJUSTMENTREMARKS 1 Con
12、nect standard loop ANTENNA to Signal Generator and radiate signal into the AM Fer- rite Antenna. See Figure 8. 455 kHz (400 H2,30% mod.) Point of non-inter- ference (near 600 kHz) Scope and, AC Volt- meter to TAPE OUT Jack. r202 T203 (AM IFT) Adjust for maxi- mum reading on meter. 2 Same as STEP 1.5
13、10 kHz (400 H2,30% mod.) Tuning Gang fully closed. Same as STEP 1. L2O3 (AM OSC Coil) Adjust for maxi- mum reading on meter. Refer to Figures 7 and 8. 3 Same as STEP 11650 kHz l4OO H2,30% mod.) Tuning Gang fully opened. Same as STEP 1. TC105 (AM OSC Trimmer) Adjust for maxi- mum reading on meter. Re
14、fer to Figures 7 and 8. 4 Same as STEP 1600 kHz (400 H2,30% mod.) 600 kHzSame as STEP 1. L8O2 (AM ANT. Coil) Adjust for maxi- mum reading on meter. Refer to Figures 7 and 8. 5 Same as STEP 11400 kHz (400 Hz, 30% mod.) 14OO kH,zSame as STEP 1. TC104 (AM ANT. Trimmer) Adjust for maxi- mum reading on m
15、eter. Refer to Figures 7 and 8. 6Repeat STEPs 4 and 5 until no further change is noticed. 7 Same as STEP 11000 kHz (400 kHz,30% mod.) Output level to 100 mV/m 1000 kHzAM Signal Meter on Set. VR201Adjust so the Meter Pointer on Receiver is at about 85% of full scale. 2 -_.4 AM BAR ANTENNA (6ocm) L/ l
16、/_ /ffi wfl FM RF L, !. i6 E )L( R655 (R636 ) -Fr 6 rn6rs + :rR6r4) I ) oo rl (06ro)J F B D6t3(D6t4) -16- 8. IC Bef. No. Value (F) illin Tolerance %l Material c247 c248 c249 c250 c251 c252 c253 c254 c255 c268 c269 c270 czl1 c272 c273 c274 c256 c257 c258 c259 c260 c261 c262 c263 c264 c265 c266 c267 c
17、275 c276 czt7 c301 c302 c303 c304 c305 1p I z.zp I 33oP I rop I 0.47 1t I I 220P I 0.47 p I 0.01 p I 220 rt I lop 680 P 0.047 p 0.0018 p 0.0018 p 1500 P 4.47 p 0.22 p 0.1 p 0.02 p 0.47 p 0.47 p 0.0018 p | 0.0018 p I 0.47 p 10.47 p l rro, I zzop I o.+z u I o.o, u I 1470 u lrrou I l+zop l+zop I o.zzp
- 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:
- Realistic-31_2077-rec-sm 电路图 维修手册 Realistic 31 _2077 rec sm 维修 手册
收音机爱好者资料库所有资源均是用户自行上传分享,仅供网友学习交流,未经上传用户书面授权,请勿作他用。



Marshall-9100-62-02-Schematic电路原理图.pdf

