RCA-Victor-Co-Inc-Q21 电路原理图.pdf

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1、PAGE 3 81-C MODELS 020 and 021 Five -Tube, Two -Band, A -C, Superheterodyne Receivers Chassis No. RC -514 Model Q2U Electrical and FREQUENCY RANGES Standard Broadcast (A) 540.1,800 kc (555.166 m) Short Wave (C) 4 5-18 me (66.7.16.6 m) Intermediate Frequency 455 kc RCA TUBE COMPLEMENT (1) RCA-6SA7 Fi

2、rst Detector-Oscillator (2) RCA-6SK7 Intermediate Amplifier (3) RCA-6SQ7. Second Detector, A.V.0 and A -F Amplifier (4) RCA -6K6 -GT Power Output (5) RCA -5Y 3-G Full -Wave Rectifier Pilot Lamp Mazda 51, 7.5 volts, 0.2 amp. POWER SUPPLY RATINGS Rating A 105-125 volts, 50.60 cycles, 50 watts Rating B

3、 105-125 volts, 25-60 cycles, 50 watts Rating C 105-125, 200.250 volts, 50.60 cycles, 50 watts Model Q21 Mechanical Specifications POWER OUTPUT RATING Undistorted Maximum 1.5 watts 2.3 watts LOUDSPEAKER Type (RL -81-A2) 5 -inch permanent -magnet dynamic Voice -coil Impedance 4.5 ohms at 400 cycles C

4、ABINET DIMENSIONS Height Width Depth Weight (net). Chassis Base Dimensions Over-all Chassis Height Tuning Drive Ratio Model Model Q20 Q21 81/4 inches 91/2 inches 12 inches 131/4 inches 63/4 inches 63/4 inches 103/4 pounds 11 pounds 101/i in. wide, 5 in. deep, 2 in. high 73/g inches 25to1 Replacement

5、 Parts Insist on genuine factory -tested parts, which are readily Identidad and may be purchased from authorized dealers. STN K DESCRIPTION STOCK DESCRIPTION CHASSIS ASSEMBLIES 35709 Shield-Top end shield for power transformer (RC -514) 35766 Socket-Dial lamp socket 31251 Socket-Tube socket 33817 Ca

6、pacitor-Mica trimmer (C3) 31319 Socket-Tube socket (6SA7) 12723 Capacitor -56 mmfd. 13638 Spring-Drive cord spring 30949 Capacitor -56 mmfd. (2nd. I -F) 35767 Support-Tuning condenser support 34699 Capacitor -100 mmfd. (1st. I -F) 30953 Switch (S3) 12720 Capacitor -100 mmfd. 35765 Switch-Range switc

7、h (S1) 12894 Capacitor -220 mmfd. 35636 Transformer-First I -F transformer 12537 Capacitor -560 mmfd. 35628 Transformer-Second I -F transformer 31405 Capacitor -6,000 mmfd. 35758 Transformer-Power transformer -110 volte, 25 30303 Capacitor-.0035 mfd. cycle-less end shields 4838 Capacitor-.005 mfd. 3

8、5757 Transformer-Power transformer -110 volts, 60 33584 Capacitor-.005 mfd. cycle-lesa end shields 14393 Capacitor-.01 mfd. 35759 Transformer-Power transformer - Univ. 80 4870 Capacitor-.025 mfd. cycle 4839 Capacitor -0.1 mfd. 35784 Volume control and power switch (S2) 35781 Capacitor-Electrolytic c

9、omprising 1 section of 33726 Washer-C washer for tuning shaft 20 mfd. and 1 section of 10 mfd. 35762 Coil-Antenna coil 35783 Coil-Oscillator coil SPEAKER ASSEMBLIES 35780 Condenser-Variable tuning condenser (RL -81A2) 32713 Core-Adjusting core and stud for oscillator coil (L5) 32907 Cap-Cone dust ca

10、p 32834 Cord-Drive cord 35570 Cone-Cone complete with voice coil 35770 Dial-Dial scale 35774 Transformer-Output transformer. 35788 Drum-Drive drum . 36043 Indicator-Station selector indicator 11785 Lamp-Dial lamp-Mazda No. 51 MISCELLANEOUS ASSEMBLIES 35769 Plate-Dial plate-less dial scale 31024 Resi

11、stor -680 ohms, watt 35104 Crystal-Escutcheon and crystal for Model Q20 30152 Resistor -1,000 ohms, 1 watt 35105 Crystal-Escutcheon and crystal for Model Q21 8073 Resistor -12,000 ohms, 2 watts 35678 Fastener-Push on fastener for crystal, Stock No. 12454 Resistor -33,000 ohms, watt 35104 12412 Resis

12、tor -47,000 ohms, watt 37882 Knob-Tuning, range switch or volume control 12285 Resistor -470,000 ohms, watt knob for Model Q20 11668 Resistor -5.8 meg., watt 35775 Knob-Tuning, range switch or volume control 13601 Resistor -10 meg., watt knob for Model Q21 35771 Shaft-Tuning shaft 30900 Spring-Retai

13、ning spring for knobs, Stock Nos. 35772 Shield-Bottom end shield for power transformer 35679 and 35775 35787 Socket-Phono input. . -r - . 收音机爱 好者资料库 RadioFans.CN PAGE 382-C Q20, Q21 Cathode -Ray Alignment is the preferable method. Connec- tions for the oscillograph are shown in the schematic drawing

14、. 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 receiver chassis, and keep the output as low as possible to a

15、void a -v -c action. Pre -Setting Dial.-With gang condenser in full mesh, the pointer should be horizontal. Precautionary Lead Dress. - 1. Green lead from oscillator section of var. condenser should he dressed away from antenna leads. 2. 6,000 mmfd. capacitor should bear against electrolytic capacit

16、or. 3. Dress blue I.F. lead against chassis. 4. .005 volume control capacitor should be dressed away from output plate leads. LS- OSC. GOOKC L2 BOTTOM L1 TOP ADJ 455 KC. .,RANGE SWITCH L3 BOTTOM L4 TOP ADJ. 455 SC. O PHONO TUNING o CONTROL VOL.1 CONTROL C2 -ANT 15 MC. C1-OSC. IS MC. TONE Cal LOWS Tu

17、be and 7 rinnner Location TONE CONTROL SWITCH FULL LOW BLUE BLACK / POWER ) % ANT. GND. CORD PHONO. CONNECTOR Back of Chassis POWER -VOLUME. TUNING CONTROL CONTROL BROA DCAST RANGE. CONTROL Alignment Procedure Steps Connect test-osc. output to- Tune test-osc. to- Turn radio dial to- Adjust the fol -

18、 lowing for max. peak output- 1 I-F grid through 0.1 mfd. capacitor and ground 455 kc Quiet point between 550-750 kc L-3 and L 4 (2nd I -F trans.) 2 1st det. grid through 0.1 mfd. capacitor and ground 455 kc L-1 and L-2 (1st I -F trans.) 3 Antenna Lead in series with 300 ohms 15 me 15 me C band C-1

19、oscillator* 4 15 me Rock at 15 me C-2 antennat while rocking 5 Antenna terminal in series with 200 mmfd. 1,500 kc 1,500 kc A band C-3 oscillator 6 600 kc Rock at 600 kc A band L-5 oscillator while rocking 7 1,500 kc1,500 kc Aband C-3 oscillator * Oscillator should track on high frequency side of sig

20、nal. If two peaks are obtained use high frequency (minimum capacity) peak. t If two peaks can be obtained use low frequency (maxi- mum capacity) peak. GAIN DATA (as taken with the RCA -Rider Chanalyst) (A) R.F.-I-F Gain (R.F.-I.F. Channel) Approximate (sain 1. Antenna to 6S7 grid 8 at 600 kc 2. 6SA7

21、 grid to plate (conversion 600 to 455 kc) 4 3. 6SA7 plate to 6SK7 grid 1 at 455 kc 4. 6SK7 grid to plate 80 at 455 kc 5. 6SK7 plate to 6SQ7 diode 7 at 455 kc (B) A.F. Gain (A.F. Channel) 1. 6SQ7 grid to plate 50 at 400 cycles 2. 6K6GT grid to plate 10 at 400 cycles (C) Oscillator Grid (0G-6SA7) Volt

22、age (Electronic Volt. Meter) 1. Oscillator Voltage at 600 kc -12V 2. Oscillator Voltage at 1,500 kt -16V 3. Oscillator Voltage at 4.5 me - 5V 4. Oscillator Voltage at 15 me - 9V (D) A.V.C. Voltage (Electronic Volt. Meter) With 0.2V. input to antenna at 600 kc -15V Controls 收音机爱 好者资料库 RadioFans.CN PAGE 383-C 收音机爱 好者资料库 RadioFans.CN