RCA-Victor-Co-Inc-94BT2 电路原理图.pdf

《RCA-Victor-Co-Inc-94BT2 电路原理图.pdf》由会员分享，可在线阅读，更多相关《RCA-Victor-Co-Inc-94BT2 电路原理图.pdf（8页珍藏版）》请在收音机爱好者资料库上搜索。

1、RCA Models R-50, R-55 I.F. 175 KC 收音机爱 好者资料库 RadioFans.CN PA ji: 578-C MODELS 94BK2 and 94BT2 Chassis No. RC -390 RC -390 Four -Tube, Electric -Tuning, Two -Band, Battery -Operated, Superheterodyne Receivers Electrical and Mechanical Specifications FREQUENCY RANGES POWER OUTPUT Standard Broadcast (A

2、 Band) 540-1,720 kc Undistorted 0.08 watt Short Wave (C Band) 5.8-15.4 me Maximum 0.18 watt Four Electric Tuning Positions 550-1,500 kc One station between approximately 550- 950 kc (Button No. 1) One station between approximately 610-1,090 kc (Button No. 2) One station between approximately 750-1,3

3、70 kc (Button No. 3) One station between approximately 845-1,500 kc (Button No. 4) Intermediate Frequency LOUDSPEAKER Type Permanent Magnet Dynamic Diameter 94BK2, 8 inches; 94BT2, 6 inches Voice Coil Impedance (at 400 cycles) 94BK2, 8 ohms; 455 kc 94BT2, 2.2 ohms RCA TUBE COMPLEMENT (1) RCA -1A7 -G

4、 First Detector-Oscillator (2) RCA -1N5 -G I -F Amplifier (3) RCA -1H5 -G 2nd Detector, A.V.C., and 1st A.F. (4) RCA -1A5 -G Power Output BATTERIES REQUIRED A, one 1.4 -volt Air Cell or 1.5 -volt Dry Cell B, two 45 -volt heavy-duty B batteries CURRENT CONSUMPTION A, 0.2 amp. at 1.4 volts B, 6.8 ma.

5、at 90 volts sOf o POWER -VOLUME CONTROL O OVL 3 O 8 Z , 1, TUNI NG Location of Controls Model 91,BTI TUNING Alignment Data: Before aligning these receivers, it is suggested that the following trimmer and core adjustments be pre-set to the mechanical dimensions given below : (a) The three trimmer con

6、densers C-30, C-3, and C-2 on rear apron should be set to maximum capacity (screws turned full clockwise) and then unscrew each about 1 turn. 3 ANT. l 3 STOCK NO. 32254 GROUND 3 Models 94BK2, 94BT2 Coil Spacing. Model 94BK2 Model 94BT2 Height 371 inches 10 inches Width 22 inches 20-13/16 inches Dept

7、h 10 inches 91 inches Net Weight 401 pounds 151 pounds Shipping Weight 531 pounds 19 pounds Chassis Base Dimensions 3 inches x 11 inches x 5 inches Over-all Height of Chassis 73 inches Tuning Drive Ratio 12 to 1 Model 94RK8 (b) Unscrew L-4 to its minimum inductance position (screw all way out) and t

8、hen screw in 8 full turns. (c) Unscrew L-6 to its minimum inductance position (screw all way out) and then screw in 6 full turns. Do not run this adjustment screw in too far (more than 12 to 15 turns) as the core will contact a lug on this coil at plus B potential caus- ing a high resistance short a

9、nd no signal (dead set). (d) Screw L-9 all the way in and then unscrew 13 full turns (about i inch of threads exposed). These pre -settings will assist in quicker align- ment, especially if the adjustments have been tampered with or new parts installed. When servicing these receivers, do not shift t

10、he positions of either the oscillator section (front) or antenna section (rear) on any of the four tandem push button coil assemblies, since their positions on the form governs the track- ing between the two circuits. The illustrations show the proper spacings of coils. The coils are coded with a sp

11、ot of paint as follows: Black-Stock No. 32250 White-Stock No. 32251 Red -Stock No. 32252 Green-Stock No. 32253 RCA VICTOR DIVISION OF RADIO CORPORATION OF AMERICA, CAMDEN N. J., U. S. A. 收音机爱 好者资料库 RadioFans.CN PAGE 579-C Alignment Procedure Cathode -Ray Alignment is the preferable method. Connectio

12、ns for the oscillograph are shown on the chassis drawing. Output Meter Alignment.-If this method is used, connect the meter across the voice coil, and turn the receiver volume control to maximum. Test Oscillator.-For all alignment operations, connect the low side of the test oscillator to the chassi

13、s, and keep the output as low as possible to avoid a -v -c action. Calibration Marks.-The tuning dial is fastened in the cabinet and can not be used for reference during alignment. Therefore calibration marks corresponding to dial readings of 600 kc, 1,500 kc, and 15.2 mo have been stamped in the pl

14、ate on the front of the chassis as shown in the accompanying drawing. These marks are used for reference during alignment. Dial Indicator Adjustment.-With the gang condenser in full mesh, the indicator should point to the extreme left (low frequency) mark on the dial scale. For additional details, r

15、efer to booklet RCA Victor Receiver Alignment. C6 1500KC C5 ANT. CIO _ OSC. BLU E ANT. BLACK ONO., 15T DET. 8. 05C. TONE CONTROL SWITCH) S3 I L12 Hi -LO SEC.ADJ. 455 KC 94BK2, 94BT2 OUTPUT 2NO DET., A.F. COI.F.1 3 2NT Lt4 TRANS. 455KC L9 - PUSH BUTTON L4 600 KC 1 ADJUSTMENTS 600 KC A0 0 0 0 0 -. BAT

16、TERY L6 C30 7 C3f C2 CABLE 600KC 15OOKC15.2MC 1500 KC / 144BT2,94BK2 SN -882 Tube and Trimmer Locations Cor nect the High Tune Test Steps Side of Test Oscillator to: Oscillator to: Push Button Turn Radio Dial to: Adjust for Maximum Peak Output: 1 1N5 -G I -F grid cap in series with .01 mfd. 455 kc B

17、.C. (5) No Signal between 550-750 kc. L13 and L14 (2nd I -F Trans.) 2 1A7 -G Det. grid cap in series with .01 mfd. 455 kc B.C. (5) L11 and L12 (1st I -F Trans.) 3 Antenna Lead (blue) in series with 200 mmfd. 1,500 kc No. 4 L20 -L26 (No.4 Push Button Adj.) C2 (ant.) 4 Antenna Lead (blue) in series wi

18、th 200 ttlmfd. 600 kc No. 1 L23 -L29 (No. 1 Push Button Adj.) LO (osc.) 5 Antenna Lead (blue) in series with 200 mmfd. 1,500 kc No. 4 L20 -L26 (No. 4 Push Button Adj.) C2 (ant.) 6 Antenna Lead (blue) in series with 200 mmfd. 600 kc No. 1 L23 -L29 *(No. 1 Push Button Adj.) L8 (osc.) 7 Antenna Lead (b

19、lue) in series with 200 mmfd. 1,500 kc B.C. (5) 1,500 kc Cal. Mark C30 (osc.) CO (ant.) 8 Antenna Lead (blue) in series with 200 mmfd. 800 Sc B.C. (5) 600 kc Cal. Mark L9 (osc.) L4 (ant.) 9 Antenna Lead (blue) in series with 200 mmfd. 1,500 kc B.C. (5) 1,500 kc Cal. Mark C30 (osc.) CO (ant.) 10 Ante

20、nna Lead (blue) in series with 300 ohms 15.2 mc S.W. (6) Signal Near 15.2 me Cal. Markt *C3 (ant.) 11 Follow the Adjustments for Electric Tuning. * Adjust L23-L29 (No. 1 push button adjustment) and L6 at the same time, rocking in for maximum signal. * Use maximum capacity peak if two peaks can be ob

21、tained, rock in for maximum signal. A weaker signal (image) should be received about one -quarter inch to the left on the dial plate. t If two signals are received, set the dial to the higher frequency (right hand) position. KAU, 51575 INDICATOR 52247 III, I1 (15.2 M.G. Rod NC. 1500KC ALIGNMENT MARK

22、S DRUM RNG OSrt*ONMAYINJM AND INDICATOR TO CdNC14C WITH MI5 L. DRUM 52266 SPRING 524131 CORO 522613 SRArT 265 2f TURNS APPPO. Dial Drive Hookup and Alignment Marko Note: The oscillator tracks 455 kc above the signal on all bands. After the receiver has been installed and the antenna connected, it is

23、 sometimes advisable to make a slight change in the adjustment of the antenna trimmer, C2. In most cases it is desirable to make this adjustment while receiving a station on No. 4 push button. How ever, if a station received on one of the other buttons is especially weak, it may be advisable to make

24、 the adjustment while receiving the weak station on this button. Precautionary Lead Dress 1. Green lead to first detector grid cap should be pulled out of the chassis as far as possible, and dressed away from the tube envelope. 2. Blue lead from push button switch to gang condenser must be dressed o

25、ver the top of the switch. 3. Leads to push button coils must be dressed close to the coils. 4. Red and blue leads to gang condenser must be dressed away from chassis. 5. Blue antenna lead must be dressed in the end of the chassis away from gang leads and coil windings. 收音机爱 好者资料库 RadioFans.CN PAGE

26、.S 80-C 94BK2, 94BT2 C2 500-330 MMF. C3 3-30 MMF SW. B.C. BOTTOM VIEW OF TUBE SOCKETS . C CS 13-490 MMF. x SL L20 - L2I - L22 - 1.2 COB 470 Met cT 20MMF. r1/ 91iB.C. L9 2 f LIO ri 527 528 529 7 IF 1I1 COILS L26 L27 L2B LZ9t) ! Lp_Arr +;x -xx IOOOMMF 7.11; . ,Le 15-400 s2 z30o y MMF _ MMF. MMF. c29 /

27、 33oommr. ANT. COILS IAT-G 15T DET. , 330 SAME CI5 RI R0 100.000,3 3.9MEG5. 1 1 1 I CORRESPONDING ANTENNA AND OSCILLATOR COILS ON EACH PUSH BUTTON ARE TUNED WITH A SINGLE ADJUSTMENT Schematic Circuit Diagram X 6 Fro O T56MMF. IISt C21- IOOMSTE C22 OOOMMF (! OTO !61 O a C23 1(C24 100 .0025 MMFT MFD-

28、R6 IMEG. VOLUME $R7 3 CONTROL 10MEG _ R IMSEG. : C25 66O MMF. I R TONE CONTROL WHITE T -6630a-3 C26 000 , MME. R9 2.2 mEGS. 600! T1 B- RIO 6604 YELLOW BROWN BLACK, 1.4 VOLT N 45 VOLT A- BATTERY B BATTERIES 152 D L15 SPEAKER PLUG L15-24DA6T2 284 04822 C27 6MFD. C-22 IO VOLUME CONTROL R-5 eU OSCILLOGR

29、APH CONNECTIONS VERTICAL HI TO THIS TERMINAL VERTICAL TO CHASSIS TO SPEAKER PLATE CURRENTS I-IA7-G OSC. 1.20 MA. DET. .49 MA. 2 -INS -G 1.37 MA. 3-IHS-G .028MA. 4 -14S -G 3.02 MA. BATTERY DRAIN - 0.2 AMP, AT 1.4 VOLTS B- 6.8 MA. AT 90 VOLTS 59V. OUTPUT I.4 V. IA5-G 83V. BLACK BLK BRN TO 13.15-G GRID

30、 2ND. DET. A.F.L A.V.C. IH5-G 1 T BATTERY CABLE L-13 PRI. ADJ. 455 KC. 2ND I.F. TRANS. 85V. 85V INS -G 1.4V LLO -BLUE ata 322 ELLO LUE F: a 0 - GREEN -I 321 32O 1g -g1.3 2a GKN 4 TO IA7-G GRID GREEN ELLOS TER. BD. YELLOWJ WHITE DOT . J I- J C 2 C-3 C-30 BOTTOM VIEW - REAR OF CHASSIS R -F Wiring Diag

31、ram and Socket Voltages NOTE: Values with star (4) are operating voltages in circuits with high series resistance. The actual measured value will be lower, depending on the voltmeter loading. TER. BD BLUE VELLO RED L2 ANT. COIL I ST DET.L OSC. IA7-G Ij .4V. 1 -Du sevii 85 45V. BLUE 1j+- L1 L -II PRI

32、. ADJ. 45S KC. C-8 C-5 ELECT. CAP. TO ANT. R.P. COIL AND SWITCH ASSEMBLY MAY BE REMOVED FROM CHASSIS BY DISCONNECTING THE SEVEN LEADS MARKED X. Measurements made to chassis unless otherwise indicated, with set tuned to a quiet point and the volume control at minimum. Values should hold within approx

33、imately 20% with rated battery voltage. PAGE 581-C 94BK2, 94BT2 Adjustments for Electric Tuning These models have six push buttons. The right-hand button con- nects the receiver for dial tuning on the Short-wave band, the next button connects for dial tuning on the Standard -broadcast band, and the

34、other four buttons are for electric tuning of four different stations in the standard -broadcast band. Each station button connects separate oscillator and antenna coils which are tandem - tuned by ganged magnetite cores, and may be adjusted for the desired stations. Use a small screwdriver or align

35、ment tool such as RCA Stock No. 31031. Allow at least five minutes warm-up period before making adjustments. Use a regular antenna for the preliminary adjustments. The procedure is as follows: 1. Stake a list of the four desired stations, arranged in order from low to high frequencies. 2. Push in th

36、e broadcast dial -tuning button (second from right), and manually tune in the first station on the list. 3. Push in station button No. 1 (left-hand) and. adjust No. 1 push button adjustment to receive this station. Turn the adjust- ing screw all the way in, to lowest frequency, and then un- screw sl

37、owly until the station is received. 4. Adjust for each of the remaining three stations in the same manner. (Clockwise adjustment of the screw tunes the circuits to lower frequencies.) 5. After installation, and with antenna properly connected, re- adjust C2 as outlined in Note under Alignment Proced

38、ure. REPLACEMENT PARTS Insist on genuine factory -tested parts, which are readily identified and may be purchased from authorized dealers. STOCK DESCRIPTION STOCK N DESCRIPTION ASSEMBLIES 4869 Screw -No. 8-32 square head set screw from drum 32259 Capacitor -3 -section variable trimmer capacitor 2-10

39、, 3-30, 100-330 mmfd. (C30, C3, C2) . 32261 Screw -Push button oscillator coil adjustment screw and mounting nut 30949 Capacitor -56 mmfd. (C17, C18, C19, C20) . 32265 Shaft -Tuning knob shaft 12723 Capacitor -58 mmfd. (C1) t 3882 Shield -Tube shield 30904 Capacitor -100 mmfd. (C21).-. 31251 Socket

40、-Tube socket 12720 Capacitor -100 mmfd. (C23) 32481 Spring -Drive cord tension spring. 12724 Capacitor -120 mmfd. (C7) 12007 Spring -Retaining spring for oscillator coil ad - 12952 Capacitor -330 mmfd. (C15) justment screw 30433 Capacitor -470 mmfd. (C28) 32255 Switch -Push button switch (S18, S19,

41、S20, 32289 Capacitor -520 mmfd. (C13) S21, S22, S23, S26, S27, S28, S29, S32, 14498 Capacitor -680 mmfd. (C25) S33) 12635 Capacitor -1,000 mmfd. (C11, C22, C26). 30953 Switch -Tone control switch (S3) 4881 Capacitor -3,300 mmfd. (C29) 32263 Transformer -First I -F transformer (L11, L12, 5107 Capacit

42、or -.0025 mfd. (C24) C17, C18) 14393 Capacitor -.01 mfd. (C16) 32264 Transformer -S e con d I -F transformer (L13, 4839 Capacitor -0.1 mfd. (C14) L14, C19, C20, C21) 31323 Capacitor -16 mfd. (C7) 32262 Volume control and power switch (R5, Sl, S2) 32254 Coil -Broadcast oscillator coil (L9) 32258 Coil

43、 -Antenna coil (Ll, L2, L3, L4) SPEAKER ASSEMBLIES (84307-2) 32260 Coil -Short wave oscillator coil (L7, LB) Model 94BT2 32256 Coil -Push button osc. series coil (L10) 32250 Coil -Push button ant. and oscillator coil (L23, 32271 Cone -Speaker cone and voice coil (L15) ):.29) 5118 Plug -3 -contact ma

44、le for speaker 32251 Coil -Push button ant. and oscillator coil (L22, 32270 Speaker complete L28) 32272 Transformer -Output transformer (T1) 32252 Coil -Push button ant. and oscillator coil (L21, L27) . SPEAKER ASSEMBLIES (84477-1) 32253 Coil -Push button ant. and oscillator coil (L20, L26) . . Mode

45、l 94BK2 32257 Coil -Push button osc. shunt coil (L5, L8). 32274 Cone -Speaker cone and voice coil (L15) 32249 Condenser -2 -gang variable condenser (C5, C6, 5118 Plug -3 -contact male for speaker C10) 32273 Speaker complete 32268 Cord -Drive cord 32272 Transformer -Output transformer (Ti) 12800 Core

46、 -Variable core and stud for antenna coil No. 32258 MISCELLANEOUS ASSEMBLIES 32266 Drum -Variable condenser drive drum 32267 Indicator -Dial scale pointer 32279 Button -Push button 32208 Plug -2 -prong male for battery cable 31935 Clip -Spring clip to hold dial scale 5119 Plug -3 -contact female for

47、 speaker cable 32276 Dial -Dial scale (glass) 12827 Plug -3 -prong male for battery cable 32277 Escutcheon -Dial scale escutcheon and crystal. 31373 Pulley -Drive cord pullley 32278 Escutcheon -Push button escutcheon Knob knob 14887 Retainer -Tuning knob shaft retainer or drive 31355 -Station select

48、or or volume control Marker -Broadcast marker tab cord pulley retaining washer 32281 12282 Resistor -880 ohms, 4 watt (R10) 32087 Marker -Push button call letter markers 13715 Resistor -88,000 ohms, 4 watt (R2) 32280 Marker -Short Wave marker tab 14580 Rsistor-100,000 ohms, 4 watt (Rl) 14267 Screw -Chassis mounting screw and washer (4 13730 Resistor -1