RCA-8PCS41-9PC41-648-741-Sams-90-9电路原理图.pdf

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1、PHOTOFACT* Folder RCA VICTOR MODELS 8PCS41, -B, -C, 9PC41A, -B, -C, 648PTK, 648PV, 741PCS VOL CONT. VERT HOLD CONT HORIZ HOLD CONT POWER SW. BRIGHTNESS CONT CONTRAST CONT CHANNEL SELECTOR li- FINE TUNING TRADE NAME MODEL RCA VICTOR TV CHASSISOPTICAL UNIT HORIZ. DEFL. HIGH VOLT.RADIOAUDIO AMP 8PCS41.

2、 8PCS41-B . 8PCS41-C. 9PC41A. 9PC41B.C . 648PTK. 648PV 741PCS . . MANUFACTURER TYPE SET TUBES POWER SUPPLY RATING TUNING RANGES KCS24B-1 KRKLA-1 KRS20A-1 KRS21A- .KCS24C-1 KRK4 KRS20B-1 KRS2LA- . KCS24C-1 KRKLA-1 KRS20B-1 KRS21A- KCS24C-1 KRK4 KRS20B-1 KRS21A- . .KCS24D KRK4 KRS20B-1 KRS21A- KCS24-1

3、 KRKl-1 KRS20-1 KRS21-1 KCS24A-1 . KRK1A KRS20-1 KRS21A- KCS24B-1 KRKlA-1 KRS20A-1 KRS21A- RCA Victor Div. Radio Corp. of America, Camden, New Jersey Projection Type Television Receiver Forty One (TV Only Models) Forty Nine (Combination Models) 110-120 Volts AC-60 Cycle 5.1 Amp. . Common to chassis.

4、 DC Probe to Point . Common to chassis. DC Probe to Point . Common to chassis. SOUND IF ALIGNMENT USING FM SIGNA ADJUST A1.A2 Al A3.A4 A5.A6 REMARKS Detune A 1. Adjust A2 for maximum deflection. Adjust for zero reading. A positive and negative reading will be obtained on either side of the correct s

5、etting. Adjust for maximum deflection. Adjust for maximum deflection. GENERATOR AND OSCILLOSCOPE Connect the synchronized sweep voltage from the signal generator to the horizontal input of the oscilloscope for horizontal deflection. DUMMY ANTENNA Direct Direct SWEEP GENERATOR COUPLING High side to u

6、ngrounded tube shield floating over mixer tube. Low side to chassis. SWEEP GENERATOR FREQUENCY 21.25MC (450KC Sweep) MARKER GENERATOR FREQUENCY 21.25MC CHANNEL 13 CONNECT SCOPE Vert. Amp. to Point % . Low side to chassis. Vert. Amp. to Point . Low side to chassis. ADJUST A3,A4, A5, A6 Al, A2 REMARKS

7、 Adjust for maximum amplitude and symmetry as per Fig 1. Adjust for maximum amplitude and straightness of diagonal line with 21. 25MC marker at center of pattern as per Fig 2. continue with step 5). VIDEO IF ALIGNMENT USING AM SIGNAL GENERATOR AND VTVM Remove AGC tube 6AT6 (V12), turn contrast contr

8、ol to maximum. Connect negative lead o 3 volt battery to pin 1 of 6AL5 (V12). Connect positive lead to chassis. DUMMY ANTENNA Direct Direct Direct Direct Direct Direct Direct Direct SIGNAL GENERATOR COUPLING High side to ungrounded tube shield floating over mixer tube. Low side to chassis. SIGNAL GE

9、NERATOR FREQUENCY 21.25MC (Unmod.) 27.25MC (Unmod.) 19.75MC (Unmod.) 21. SMC (Unmod.) 25. SMC (Unmod.) 22. SMC (Unmod.) 25.2MC (Unmod.) 23.4MC (Unmod.) CHANNEL 13 CONNECT VTVM DC Probe to Point . Common to chassis. ADJUST A7.A8 A9 A10 All A12 A13 A14 A15 REMARKS Adjust for MINIMUM deflection. Adjust

10、 for maximum deflection. OVERALL VIDEO IF RESPONSE CHECK Connect the synchronized sweep voltage from the signal generator to the horizontal input of the oscilloscope for horizontal deflection. DUMMY ANTENNA Direct SWEEP GENERATOR COUPLING High side to ungrounded tube shield floating over mixer tube.

11、 Low side to chassis. SWEEP GENERATOR FREQUENCY 24MC (10MC SWP) MARKER GENERATOR FREQUENCY 22. SMC 25.75MC CHANNEL 13 CONNECT SCOPE Vert. Amp. to Point . Low side to chassis. ADJUSTREMARKS Check for response shape of response curve and placement of markers as per Fig 3. If necessary slightly retouch

12、 All thru A15 for optimum results. * fcS oo O O m H JJJ CO o*. o IS si FIG.IFIG.2 FIG. 3 PAGE 7 RadioFans.CN TV ALIGNMENT INSTRUCTIONS CCONTJ RF AND MIXER ALIGNMENT Replace local oscillator tube (V3). Connect a 1000MMF capacitor from first video IF grid (pin 1) to chassis. Keep leads of capacitor as

13、 short as possible. Reduce bias voltage supplied by battery to -1 volt. The sweep generator should be terminated with its characteristic output impedance (usually 50 ohms). The RF and mixer adjustments are noramlly very stable and should not be attemped unless they are definitely known to be out of

14、adjustment. Connect the synchronized sweep voltage from the signal generator to the horizontal input of the oscilloscope for horizontal deflection. DUMMY ANTENNA Two 120J! carbon res. SWEEP GENERATOR COUPLING To antenna terminals with 120SJ resistor in each lead. SWEEP GENERATOR FREQUENCY 177MC (10M

15、C SWP) 183MC (10MC SWP) 189MC (10MC SWP) 195MC (10MC SWP) 201MC (10MC SWP) 207MC (10MC SWP) 213MC (10MC SWP) 85MC (10MC SWP) 79MC (10MC SWP) 69MC (10MC SWP) 63MC (10MC SWP) 57MC (10MC SWP) MARKER GENERATOR FREQUENCY 177. 25MC 179. 75MC 181. 25MC 185.75MC 187.25MC 191. 75MC 193.25MC 197.75MC 199.25MC

16、 203.75MC 205.25MC 209.75MC 211. 25MC 215.75MC 83.25MC B7.75MC 77. 25MC 81. 75MC 67. 25MC 71. 75MC 61. 25MC 65. 75MC 55.25MC 59. 75MC CHANNEL 7 8 9 10 11 12 13 6 5 4 3 2 CONNECT SCOPE Vert. Amp. to Point jin series with lOKn. Low side to chassis. ADJUST A16.A17, A18.A19 A20, A21, A22.A23 REMARKS Adj

17、ust for flat topped response as per Fig 4 with markers above 70%. Check for response curve as per Fig 4. Check for response as per Fig 4. If markers are below 70% on any channel make slight readjustment of A16, A17, A18 and A19 with channel selector on that channel. Recheck other high band channels

18、for optimum re- sponse. Adjust for flat topped response as per Fig 4 with markers above 70%. Check for response as per Fig 4. If markers are below 70% on any channel make slight readjustments of A20, A21, A22 and A23 with channel selector, on that channel. Re- check other low band channels for optim

19、um response. OSCILLATOR ALIGNMENT Remove 1000MMF capacitor. DUMMY ANTENNA Two 120S2 carbon res. SIGNAL GENERATOR COUPLING To antenna terminals with 120ft resistor in each lead. SIGNAL GENERATOR FREQUENCY 215.75MC (Unmod.) 209.75MC 203.75MC 197. 75MC 191. 75MC 185. 75MC 179. 7 SMC 87.75MC 81.75MC 71.

20、 75MC 65. 75MC 59. 75MC CHANNEL 13 12 11 10 9 8 7 6 5 4 3 2 CONNECT VTVM DC Probe to Point . Common to chassis. ADJUST A24.A25 A26 A27 A 28 A29 A30 A31 A32,A33 A34 A35 A36 A3? REMARKS Adjust for zero reading. A positive and negative reading will be obtained on either side of the correct setting. Kee

21、p A24 and A25 slugs at approximately the same relative position. Adjust for zero reading. A positive and negative reading will be obtained on either side of the correct setting. t for zero reading. A positive and negative reading will be obtained on either side of the correct setting. Keep A32 and A

22、33 slugs at approximately the same relative positions. MIXER GRID TRAP ADJUSTMENT A. Connect output of sweep generator to antenna terminals as in RF and m xer alignment. B. Connect oscilloscope to Point E thru lOKfi C. Connect a 1000MMF capacitor from grid of first Video IF to chassis. D. Turn chann

23、el switch and sweep thru low frequency channels, and select a channel with essentially flat response with markers above 80%. E. Remove shunt capacitor from first video IF amplifier and shunt grid of second video amplifier grid to chassis. F. Adjust A38 (rear of tuner) for response similar to the one

24、 obtained when first video IF grid was shunted. NOTE : In some later models A38 is a fixed capacitor (C21). In those receivers this step may be used as a check of correct mixer operation. WAVE TRAP ADJUSTMENT Wave traps A39 and A40 are used for specific types of interference and their alignment will

25、 depend upon the type encountered. With the receiver tuned to the channel having the interference set fine tuning control until interference is at maximum.Adjust A39 and A40 for minimum interference in the picture and sound, keeping the cores at approximately the same relative position. Turn one cor

26、e 1/2 turn, adjust the other for minimum interference. FIG.4 PAGE 8 RadioFans.CN RADIO ALIGNMENT INSTRUCTIONS 21 22 23 24 25 26 27 28 29 30 31 32 33 ALIGNMENT INSTRUCTIONS READ CAREFULLY BEFORE ATTEMPTING ALIGNMENT All critical lead dress should be performed before alignment. Alignment should be per

27、formed in the order outlined, If an y portion of the set is aligned, perform all steps after that portion. To set pointer turn tuning cap fully closed and set pointer to last reference mark at low frequency end of dial. FM IF ALIGNMENT Turn the function selector switch to FM (maximum clockwise). Con

28、nect two matched 100Kn(f 1%) resistors in series from point F to chassis. The junction of these two resistors is alignment point H as shown on the schematic. Volume control should be at maximum position. Output of signal generator should be no higher than necessary to obtain an output reading. Use a

29、n insulated alignment screwdriver for adjusting. Connect an output meter across the speaker voice coil. DUMMY ANTENNA . 01MFD .01MFD .01MFD . 01MFD SIGNAL GENERATOR COUPLING High side to pin 1 (Grid) of 6AU6 (V47). Low side to chassis. High side to pin 1 (Grid) of 6BA6 (V42). Low side to chassis. SI

30、GNAL GENERATOR FREQUENCY 10. 7MC (30% mod. 400 1- AM) BAND SWITCH POS. FM (max. CW) RADIO DIAL SETTING Tuning gang fully closed CONNECT VTVM DC Probe to PoinK . Com- mon to chassis. DC Probe to Point. Com- mon to pointp DC Probe to Point. Com- mon to chassis. ADJUST A41 A42 A43 A44, A45, A46, A47, A

31、48, A49 REMARKS Connect a 680S2 resistor between terminals D and E of L46. Adjust for maximum de- flection. Remove the 680S2 resistor. Adjust for zero reading. A positive and negative reading will be obtained on either side of the correct setting. The voltage should change rapidly as zero is approac

32、hed. A slow approach towards zero indicates severe detuning and A39 should be turned in the opposite direction. Adjust for MINIMUM output on the output meter connected across voice coil. If mini- mum output and zero voltage on the VTVM do not occur at the same settings of A39 and A40, it may be nece

33、ssary to adjust A39 and A40 simultaneously until minimum audio output and zero voltage on VTVM occur at the same point. Repeat step 21 omitting the 680ft resistor. Remove the output meter. Alternately load the primary and secondary of each transformer while the opposite side of the same transformer

34、is being adjusted. Adjust for maximum deflection. AM ALIGNMENT Loop should be maintained in same relative position to chassis as when receiver is in cabinet. Volume control should be at maximum position. Output of signal generator should be no higher than necessary to obtain an output reading. Use a

35、n insulated alignment screwdriver for adjusting. DUMMY ANTENNA . 01MFD 25MMF capacitor in series with a 150SI car- bon res. 200MMF 200MMF DUMMY ANTENNA Two 120SJ carbon res. SIGNAL GENERATOR COUPLING High side to pin 1 (Grid) of 6BA6 (V42). Low side to chassis. High side thru dummy to antenna termin

36、al 4. Low side to chassis. High side to antenna termin- al 4. Low side to chassis. SIGNAL GENERATOR COUPLING Across antenna terminals 4 and 5 with 12WJin series with each lead. Not used Not used SIGNAL GENERATOR FREQUENCY 455KC (400 1 ModJ 15. SMC 9. SMC 1400KC 600KC SIGNAL GENERATOR FREQUENCY 106MC

37、 88MC 106MC 90MC BAND SWITCH POS. C band second pos. CCW) A band (third pos. CCW) fk BAND SWITCH POS. FM RADIO DIAL . SETTING Tuning gang fully open 15. 5MC 9. SMC 1400KC 600KC RF ALIGNMENT RADIO DIAL SETTING 106MC 88MC 106MC 90MC OUTPUT METER Across voice coil Across voice coil ADJUST A50, A51, A52

38、, A53 A54, ASS, A56 A57, ASS, A59 A60, A61, A62 A63, A64, A65 REMARKS Alternately load the primary and secondary of each transformer with a lOKfi resistor while the opposite side of the same trans- former is being adjusted. Adjust for max- imum output. Adjust for maximum output. Tune the signal gene

39、rator to 16.41MC and increase the output. A signal should be heard. If it is not, reset the signal generator to 15. SMC and open A51 to the next peak and recheck for image. Adjust for maximum output. Tune the signal generator to 10. 41MC and increase the output . A signal should be heard. If it is n

40、ot the set is incorrectly aligned, therefore repeat steps 26 and 27. Adjust for maximum output. Adjust for maximum output. Repeat steps 28 and 29 until no further improvement can be made. CONNECT VTVM DC Probe to Point A F AMP vnfc . PHASE INV. VgB f=f MlDigOUTPUT V2oB 1 VIDEO AMP V9 h| 1 1 OKJDWn |

41、 VtfHT nilTDTIT USI 1 1 30 hi | H V flECT. V.14 )| j I 31 H V DECT. V35 1 1 | .JHVBECT. V3| 29m, 1 REST. 1/2 VI 1 1 1 8 BLOCK DIAGRAM DISASSEMBLY INSTRUCTIONS 1. Remove five push-on type knobs from controls. 2. Remove base socket of picture tube and feed thru hole in dust cloth. Some plugs connectin

42、g the various units are held in with 1/4 hex head bolts. Make sure these are removed before withdrawing plugs. 3. Remove plug of shielded cable from Hor. deflection chassis and feed cable thru hole in dust cloth. 4. Remove plug from left rear of TV chassis and feed cable thru dust cloth. 5. Loosen s

43、crew holding yoke clamp and slide yoke off neck of picture tube. jlate over neck of picture tube.Loosen three screws holding clamps over glass plate. Push clamps aside and remove glass Loosen three screws around large end of picture tube and remove tube. Remove power plug from left rear corner of po

44、wer supply chassis leadingto Hor. deflection chassis. Remove plug on left side of deflection chassis. This cable leads to power supply chassis. Remove two plugs on right rear of TV chassis. These cables lead to Hor. deflection chassis. . Remove three 3/8 hex head bolts holding Hor. deflection chassi

45、s to cabinet. Remove the chassis with care as HV lead to picture tube is still connected. Turn chassis over and remove sixteen 1/4 hex head bolts from bottom cover. Unsolder HV lead. Loosen clamp screws on top of Hor. deflection chassis and remove HV lead from this unit. 12. Disconnect short black p

46、ower lead plug of power supply chassis. This cable leads to audio amplifier chassis. 13. Disconnect plug on right rear of TV chassis leading to power supply chassis. 14. Remove four 3/8 hex head bolts holding power supply chassis to cabinet. Remove chassis. 15. Remove speaker plug at speaker. This c

47、able leads to audio amplifier chassis. 16. Remove octal plug from center of audio amplifier chassis. 17. Remove bayonet plug from center of audio amplifier chassis. 18. Remove panel lamp from inside bottom front of cabinet. 19. Remove four 3/8 hex head bolts holding audio amplifier chassis to side o

48、f cabinet, using care to hold chassis. Remove chassis. 20. Remove octal plug from upper right corner of TV chassis. This cable leads to resistor chassis. 21. Remove two screws holding resistor chassis to cabinet. Remove chassis. 22. Remove four hex head nuts 11/32 holding speaker to cabinet. Remove

49、speaker. 23. Remove bayonet plug from center of TV chassis. This cable goes to audio amplifier chassis. 24. Remove two phillips head screws holding antenna terminal strip to upper left of cabinet. 25. Remove two 3/8 hex head bolts holding TV chassis to cabinet, holding chassis to prevent it falling. Remove TV chassis. 26. To remove picture tube housing, remove three 5/8 hex nuts holding picture tube housing to cabinet. Lift unit and remove. 27. Remove four screws holding on-off switch to control panel of cabinet. 28. Remove four screws holding automatic on-o