RCA-Victor-Co-Inc-25BT-3 电路原理图.pdf

《RCA-Victor-Co-Inc-25BT-3 电路原理图.pdf》由会员分享，可在线阅读，更多相关《RCA-Victor-Co-Inc-25BT-3 电路原理图.pdf（6页珍藏版）》请在收音机爱好者资料库上搜索。

1、PAGE 404-C MODELS 25BK and 25BT-3 Chassis No. (RC -1004B) and CV -42 Electrifier 25BK 25BT-3 CV -42 Specifications FREQUENCY RANGES Standard Broadcast (A Band) 540-1720 kc Short Wave (C Band) 6.0-18.0 mc INTERMEDIATE FREQUENCY 455 kc RCA TUBE COMPLEMENT (1) RCA 1N5 -GT R -F Amplifier (2) RCA 1A7 -GT

2、 Detector -Oscillator (3) RCA 1N5 -GT I -F Amplifier (4) RCA 1H5 -GT 2nd Detector, A -F and A.V.C. (5) RCA 3Q5 -GT Power Output POWER SUPPLY 1 A - B 11-90 volt pack. These models can be operated on 105-125 AC, 50-60 cycles or 105-125 volts DC, by means of an RCA CV -42 Electrifier. Mix. POWER OUTPUT

3、 3 watt BATTERY DRAIN 3 amperes 10 m.a. (Switch at Battery Saver position) 14 m.a. (Maximum output position) IMPORTANT LOUDSPEAKERS (PM) 25BK 25BT3 Remove any external ground connections when using the Identification number 92355-1 RL -93-1 Electrifier. Diameter 9 inch elliptical 5 inches CAUTION: T

4、urn power switch off (cou.tter-clockwise) when installing or replacing tubes or batteries. DO NOT TURN THE BATTERY -ELECTRIC SWITCH TO ELECTRIC POSITION WHILE THE RECEIVER IS CONNECTED TO BATTERIES. POWER CONSUMPTION (CV -92) 22.5 watts Alignment Procedure Cathode Ray Alignment is the preferable met

5、hod. Connections for the oscillograph are shown in the diagram. Output Meter Alignment.-It 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 r

6、eceiver chassis, and keep the output as low as possible to avoid A.V.C. action. Electronic Voltmeter.-The electronic voltmeter in the Chanalyst or VoltOhmyst provides an unexcelled output indicator. It should be connected to the A.V.C. bus. Pre -Setting Dial.-With gang condenser in full mesh, the po

7、inter should be set at the left-hand end dial calibration mark. Precautionary Lead Dress: - 1. All filament wires should be dressed close to chassis. 2. Keep AVC lead connecting .1 Mfd. Filter to Ant. Coil away from 1A7GT plate. 3. Keep grid lead coming from first IF transformer short. 4. Keep Blue

8、leads coming from IF transformer short and close to chassis. 5. Keep grid leads of 1N5GT and 1A7GT tubes away from each other. SHOWN WITH GANG AT MAX. CAPACITY. DRIVE CORD DEUM 3 TURNS Step Connect high side of test osc. to- Tune test-osc. to- Turn radio dial to- Adjust the follow - ing for maximum

9、peak output 1 I -F grid, in series with .01 mid. 455 kc A Band, Quiet point between and 750 kc C14 and C15 (2nd I -F trans.) 2 1st Det. grid in series with .01 mid. C12 and C13 (1st I -F trans.) 3 Antenna terminal in series with 220 mid. 18 me 18 me C17 (Osc.) 4 5 1720 kc Tuning condenser rotor plat

10、es all out G22 (Oat.) 800 kc 800 kc (Rock) 6 1300 kc 1300 kc signal C9 (Ant.) C25 (Det.) 7 Repeat steps 4. 5, and 8 8 Antenna terminal in series with 300 ohms 11.5 me 11.5 me signal C34 (Ant.) Cao- ANT. 11.5 MC. DUMMY TERM. 4C1720 KC.22-o5C. CGoo KC.25-oXe 25873 RCA VICTOR DIVISION OF RADIO CORPORAT

11、ION OF AMERICA, CAMDEN N. J., U. S. A. 收音机爱 好者资料库 RadioFans.CN PAGE 405-C 256K, 256T3, CY212 o o + e og U 114 sg uln m L I rW e Z OI 0, l, /N0,13 A6,2 NMo39 fl tog Ilno 004UI UN UN er (VI ff JN 321 -Wig uj Z - d1 -r - l9 LO 0 nty II i !NI .o OA- E o o m e,13 -/IINJ-rr-Ny R3111 Ln - do O K O -/I ;14i

12、 HI, o0 0 N v. I Y ,3.1 d e HI O rN IYN - *-r Jd W H 90 NF Ng, 0 yJ U_ NQ Up UN J m3 512 vEL UN 1na6 I e M Mtn/ 0 N UN IHI. ec Q x - *de I I z NInLLQi0 o m i v5E D .,:fr ; HII O 0 %2,070 收音机爱 好者资料库 RadioFans.CN PAGE 406-C 25BT2, B52, CV42 POWER +05-125 5o Tb PLATES SUPPLY AND v. -G0. cv DC. CABLE PL

13、UG (PRONG VIEW) SCREENS TERMINAL USING CV -42 ELECTRIFIER / OuTFUT 2ND DEFAF I F RF 1ST DET OSC. S1 _A 3OS6T 1115GT 1N5GT IN56T 1A7GT IIOV s ii3: A +1 2 x OIO g4L LAST / (*ccal. v./) I -B CASE C00rIUMEliruIIuIJ.,. collrgOL 54 R17 22 2.T MEG Geo I R11 390 I C23 10 R10 390 Cle 1 10 35Z5GT 0 920117-1 7

14、 b e MFD. 1 MFD. .1922144 Cv42 Circuit II Wuiilll of CV -42 Electrifier ADD THIS I 22O MMF.R ANT. COIL II_/ IIII _ Simplified Hum Modulation on The following changes Diagram when using Model 25BT3 should be of Filament Circuit CV -42 When Using CV made in cases -42 Electrifier. where hum modula - BL

15、UE ANT IL i gL GND ORIGINAL 25BT3 I1, 1 ifi. r, CONNECTIONS C19 05 BLUEy ANT GND Insist on genuine BL K NEW factory -tested fion is experienced when operating Model 25BT3 from a CV -42 41111111111 C19 electrifier power unit. It is not necessary to remove the chassis from .OS the cabinet to make thes

16、e changes. S (1) Connect a 220 mmfd. molded mica capacitor in series with the ADD TIRS blue antenna lead as shown. JUMPER (2) Disconnect the black ground lead and C19 from the bottom lug SOLDER TO CHASSIS on the antenna coil. Connect a jumper from this lug to chassis. Connect the black ground lead t

17、o C19 and tape the joint. CONNECTION S 25BT3 The original and revised connections are shown at left. Replacement Parts parts, which we readily identified and may be purchased from authorized dealers. STOCK . DESCRIPTION STOCK No. DESCRIPTION 38675 36083 30314 38706 38671 38192 37359 13002 13545 1272

18、3 13057 12694 36247 34566 33584 4858 32787 32786 38819 38820 36191 1 36186 38080 32634 38822 38678 38193 38350 38678 30550 38674 13999 30498 12262 14720 30146 12412 13715 14583 13730 30649 12928 30992 3903 36195 CHASSIS ASSEMBLIES (RC -1004B) Arm-On-Off indicator and arm assembl Y . Can-Shield can f

19、or I.F. transformers Cap-Grid cap Capacitor-Electrolytic, comprising 1 section of 20 mfd., 90 volts, 1 section of 12 mfd., 90 volts, and 2 sections of 10 mfd., 10 volts Capacitor-Adjustable capacitor comprising 1 sec- Lion of 450-600 mmfd., and 1 section of 5-20 mmfd. Capacitor-Mica trimmer -3-30 mm

20、fd. Capacitor-Comprising 1 section of .005 mfd., and 1 section of .0003 mfd. Capacitor -12 mmfd. Capacitor -39 mmfd. Capacitor -56 mmfd. Capacitor -68 mmfd. Capacitor -220 mmfd. Capacitor -3900 mmfd. Capacitor-.0018 mfd. Capacitor-.005 mfd. Capacitor-.01 mfd. Capacitor-.05 mfd. Capacitor -0.1 mfd. C

21、oil-Antenna coil Coil-Oscillator coil Coil-R.F. coil Condenser-Variable tuning condenser Control-Volume control Cord-Drive cord (approx 42 -in. overall length) Dial-Dial scale for 25BT3 Drum-Drive drum for tuning condenser Indicator-Station . selector indicator Lever-Indicator arm actuating lever Pl

22、ate-Dial back plate complete with pulleys and Off -On indicator arm Plug -4 -prong male plug for battery cable Pulley-Drive cord pulley Resistor -22 ohms, 1 watt Resistor -390 ohms, watt Resistor -680 ohms, watt Resistor -1,000 ohms, i watt Resistor -4,700 ohms, watt Resistor -47,000 ohms, i watt Re

23、sistor -68,000 ohms, watt Resistor -220,000 ohms, watt Resistor -1 meg., watt Resistor -2.2 meg., watt Resistor -3.3 meg., watt Resistor -10 meg., watt Screw-No. 8-32 cup point set screw Shaft-Tuning knob shaft . 31251 31418 38349 35098 38670 36188 36082 38343 36194 32907 36426 39066 38824 38822 388

24、38 36886 36722 30900 38702 38701 30847 28451 35069 28452 38702 30730 31027 31251 38702 Socket-Tube socket Spring-Drive cord spring Spring-Indicator rm return spring Spring-To hold I.F. transformers in shield cans Switch-Power switch Switch-Range switch Transformer-First I.F. transformer-less shield

25、can, spring and grid cap Transformer-Second I.F. transformer-1 e s s shield can and spring Transformer-Output transformer SPEAKER ASSEMBLIES FOR MODEL 25BT3 (RL -93-1) Cap-Dust cap Cone-Cone complete with voice coil SPEAKER ASSEMBLIES FOR MODEL 25BK (92378-1) Cone-Cone complete with voice coil MISCE

26、LLANEOUS ASSEMBLIES Decalcomania-Control panel decal Dial-Glass dial scale for 25BK Escutcheon-Dial scale escutcheon-less dial Knob-Rangeolucontrolwitch or power switchgn knob Knob-Volume or tuning knob Spring-Retaining spring for knobs CV -42 ELECTRIFIER (No. 38700) Ballast-Plug-in ballast tube res

27、istor Capacitorlectrolytic, comprising 1 section of 50 mfd., 150 volts, 1 section of 30 mfd., 150 volts, and 1 section of 100 mfd., 10 volts Capacitor-.05 mfd., 400 volts Cover-Insulating cover for electrolytic capacitor Fastener-Push fastener for bottom cover Plate-Bakelite mounting plate for electrolytic c2pacitor Resistor-Ballast tube resistor Resistor -2,700 ohms, watt Socket-Power output socket Socket-Tube or ballast resistor socket Tube-Ballast tube resistor 收音机爱 好者资料库 RadioFans.CN