RCA-Victor-Co-Inc-8M 电路原理图.pdf

PAGE 478-C MODEL 8M Five -Tube, Superheterodyne Automobile Receiver RADIOTRON COMPLEMENT Model 8M Electrical Specifications (3) RCA -6Q7 -G. Second Det., A -F Amp., and A.V.C. (1) RCA-6A8G. First Detector-Oscillator (4) RCA -6K6 -G Power Output (2) RCA -6K7 -G IF Amplifier (5) RCA -6X5 -G Full -Wave Rectifier Tuning Range 530 to 1,550 kc POWER OUTPUT RATING LOUDSPEAKER Maximum 3.3 watts Type 5 -inch Electrodynamic Undistorted 1.75 watts Voice -Coil Impedance 3.2 ohms at 400 cycles POWER SUPPLY RATING Supply Voltage 6.3 volts Current Drain 6 amp. Fuse Protection 15 amp. PILOT LAMP Mazda No. 51, 7.5 volts, 0.2 amp. Alignment Remove all external screws to remove the chassis from the ase. Hold the condenser gang in full -mesh position while rotating the dial scale so the low frequency (end) calibration mark is in line with the pointer. Loosen the three nuts in the front of the scale assembly for this adjustment. When refer- ring to scale settings hold the front panel in place. Perform alignment in proper order tabulated below, start- ing with No. 1 and following all operations across, then No. 2, etc. Adjustment locations are shown on figures 1 and 4. Cathode-ray alignment is preferable; the connections to the chassis are shown on figure 3. If an output indicator is used, connect it across the loudspeaker voice -coil and advance the receiver volume control to 41 -volume position. Connect the low output terminal of the test oscillator to the receiver chassis for all alignment operations. Regulate Figure 1-Radiotron, Component Part, and Trimmer Locations Procedure the output of the test oscillator so that minimum signal is applied to the receiver to obtain an observable output indi- cation. This will avoid a -v -c action. The term Ant. Cable means test oscillator signal should be applied to the receiver at the connector on the antenna cable extending from the receiver chassis. Dummy antenna means the device which must be connected between the high test oscillator output and the point of connection to the receiver in order to obtain ideal alignment. No signal, 550.750 kc means that the receiver should be tuned to a point between 550 and 750 kc where no signal is received from a station or the local (heterodyne) oscillator. For further details on alignment, refer to booklet RCA Victor Receiver Alignment. Order of Alignment Test Oscillator Receiver Dial Setting Circuit to Adjust Adjustment Symbols Adjust to Obtain Connection to Receiver Dummy Antenna Frequency Setting 1 6K7 -G I -F Grid Cap .001 Mfd. 480kc No Signal 550-750 kc 2nd I -F Trans. L6 Max. (peak) 2 6A8 -G Det. Osc. Grid Cap ,001 Mfd. 460 kc No Signal 550-750kc 1st I -F Trans. L4 and L5 Max. (peak) 3 Ant. Cable 100 Mmfd. 1,400 kc 1,400 kc Osc. C5 Max. (peak) 4 Ant. Cable 100 Mmfd. 1,400 kc 1,400 kc H -F Ant. C2 Max. (peak) 5 Ant. Cable 100 Mmfd. 600 kc Approx. 600 kc * L -F Ant. Ll Max. (peak)t 6 Ant. Cable 100 Mnifd. 1,400 kc 1,400 kc H -F Ant. C2 Max. (peak) * Adjust dial for maximum output at or near 600 kc setting. t The same inductance may be obtained for two different settings of Ll. Use either settin:. 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 Antenna Compensating Capacitor.-Trimmer C2 is acces- sible from the bottom of the receiver case (near speaker open ing) and should be readjusted to give maximum signal out, put on a weak station or oscillator signal at approximately 1,400 kc, after the instrument is installed. The antenna should be connected to the receiver during this adjustment. Refer to Alignment Table operation number 6. OREEN CZ C3 ,r3-3OMMF./ 9-365MMF. r L1 C5 - C6 2 1 3-15MMF. 9-365MMc j11 C1 680 MMF. C4, 0.1 MFD. YELLow Rt = 56,000n DIAL BLACK LAMP L2 l l3 o o r p pppp . b L3 6n 1 R Cl 1ST DET.VOSC. 6ABG L4 390MMF 5.6 MME. (ON SOME MODELS) PAGE 179-C 6M NOTE: Change Cl from 580 mnfd to 300-400 mmfd for use with high capacity built-in antennas. I.F 6K7G -IIr L5-7.2, C (TOP) C8 :10 MMF TO ALL HEATERS FIELD YELLOW_ L9 4.8n E -_-1 BLUE C18 L8 I 0.6 L12 _j MFD. y AHOT FUSE SI TL10-.03A I p (p16BR0 I FI L-0 1 11 i p RII . SPARK CI REAK - D- / o 6XGi 0.3 ?I 100 A.- BLC PLATE _ HEATER L_1 l GREEN YELLOW C9 110 MMF R2 2.2MEG 2. DET., A. F. Q A.V.C. 6070 L6, F ifr ,LT -9.6n CIO 47 MME B C12 470 MMF .0 CI3 a - .05MFD. VOLUME CONTR. R3 TfC11 R4 kR7 kRB - 15,000n I 0.1 500,000n ,39, 39n MFD. R12 100n C19 RECT. .0075MFD. 6X5G R13 -15,000n- BROWN -BLACK Figure 2-Schematic Circuit Diagram R6 270 n pZ C20 0.25 MFD. R14 1200n C15 .01 MFO. OUTPUT 6K6 G C16 .005 MED. 470,000n RCA M-81929-3 GREEN RED 451, 15% BLACK BLACK- 0.37 LII T2 C2 l 1 C22 I l C 23 6MFD, 6MFD. IOMFD. -Fitt11L i-. _1 POWER SWITCH 4 VOLUME CONTROL S1 R4 TO C5,C6 GREEN L2 L8 C13 OSC L3 COIL. L2 L3 OUTPUT 6 K6G GREEN W 5.6 MMF. 7 on Some ) MODELS C20 O 2-0. DET: A.F-AVC 6Q 7G -1 R DET ; I. F. 647-G C21 -RED VIBRATOR C 23 CATHODE CURRENTS N. I . to mallo.2 GATE N4. . 28 m. NS. .44.511544 *CANNOT BE MEASURED AT SOCKET. Figure 4-Radiotron Socket Voltages and Trimmer Locations (Measured at 6.3 volts battery supply-Volume control minimum-No signal input) Note: Two voltage values are shown for some read- ings. The value shown in parentheses with asterisk () indicates operating conditions without voltmeter loading. The other value (generally lower) is the actual measured voltage and differs from the value shown in parentheses because of the additional loading of the voltmeter. REPLACEMENT PARTS Vibrator Hum: Some instruments may produce a mechanical hum which is accentuated when the instrument is mounted in a car and attached to the instru- ment panel. If this condition is apparent, a strip of felt t -inch x 13 -inch x i -inch should be installed between the vibrator unit and the power transformer, and cemented to the trans- former. Dial Slippage: The following procedure is suggested to over- come slippage of the dial drive, resulting from the dial scale rubbing against the case. (a) Remove the three nuts which hold dial it place and take dial off of dihl drive drum. (b) Loosen two set screws on hub of dihl drive drum. Move drum as far as possible toward chassis, allowing just enough clerance tc prevent its scraping against the two bras screw heads. (c) Replace dial and make sure that the dial scale is concentric with the shaft, before tightening the dial mounting nuts. (d) Mount chassis as far back in case as pos- sible. (e) Mount chassis so that dial is centered fron - left to right with respect to the case. (f) If dial scale is loose in its mounting, slightly crimp edge of brass mounting with diagonal cutters. (g) See that rubber grommets are in place in shaft holes of case. (h) Mount the case -end as far forward as pos- sible. Loudspeaker Cones: Speaker marked 84147-2 is used in 8M, but has two types of cones, which vary as to mount- ing dimension of the spider suspension: Stock No. 35484 cone fits speaker marked 84147-2 with a 21 inch dimension between suspension points. Stock No. 30782 cone fits speaker marked 84147-2 with a 2-9/16 inch dimension be- tween suspension points. I nsist on genuine factory -tested parts, which are readily identified and may be purchased from authorized dealers. Stock No, DESCRIPTION Stock No DESCRIPTION RECEIVER ASSEMBLIES 12679 Resistor -2.2 Megohm, insulated, watt (R2) - Package of 5 11350 Cap-Grid contact cap-Package of 5 5129 Ring-Retaining ring for Radiotron shield-Pack- 30637 Capacitor-Adjustable trimmer (C2) age of 5 12405 Capacitor -47 Mmfd. (C10) 12418 Screw-No. 8-32 x 3/16 -in. slab -head set screw for 14262 Capacitor -110 Mmfd. (C8, CO) drum, Stock No. 30630-Package of 10 13894 Capacitor -390 Mmfd. (C14)-Package of 5. 30638 Shield-Radiotron shield 30625 Capacitor -390 Mmfd. (C7) 13686 Socket -4 -contact vibrator socket 30673 Capacitor -470 Mmfd. (C12) 11196 Socket -8 -contact Radiotron socket 14498 Capacitor -680 Mmfd. (C1)-Package of 5 30631 Spring-Tensicn spring for drive cord-Package of 4838 Capacitor-.005 Mfd. (C16) 10 30626 Capacitor-.0075 Mfd. (C19) 14376 Transformer-First I.F. transformer (L4, L5, C8, 14393 Capacitor-.01 Mfd. (C15) C9) . 4886 Capacitor-.05 Mfd. (C13) 30672 Transformer-Second I.F. transformer (L6, L7, 4839 Capacitor -0.1 Mfd. (C4, C11) C10, C12) 12484 Capacitor -0.25 Mfd. (C20) 30633 Transformer-Vibrator power transformer (Tl, L10, 30634 Capacitor Pack-Comprising two 6 Mfd. and one C18) 10 Mfd. sections (C21, C22, C23) 13688 Vibrator-Plug-in vibrator (L12) 4358 Clamp -Mounting clamp for capacitor pack, Stock 30628 Volume Control and ON-OFF switch (R4, Si) . No. 30634 30639 Coil-Antenna coil-less shield (L1) REPRODUCER ASSEMBLIES (84147-2) 30636 Coil-Oscillator coil (L2, L3) 30627 Condenser -2 -gang variable tuning condenser (C3, $ 30782 Cone-Reproducer cone and voice coil (L11) Cl, C6) 30781 Reproducer, complete (L8, L11, T2) 30632 Cord-Drive cord-Package of 5 30783 Transformer-Output transformer (T2) 30629 Dial-Dial scale and holder 30630 Drum-Dial drive drum, complete with set screws MISCELLANEOUS ASSEMBLIES 12415 Resistor -39 ohms, insulated, I watt (R7, R8)- Package of 5 5025 Capacitor-Generator capacitor 30540 Resistor -100 ohms, insulated, I watt (R11, R12) 5023 Fuse -15 amp,-Package of 5 -Package of 5 30640 Housing-Receiver case only 13744 Resistor -270 ohms, carbon type, watt (R6)- Package of 5 4290 Insulator-Fuse-holder insulating sleeve-Package of 10 6134 Resistor -1,200 ohms, carbon type, 1 watt (R14) -Package of 5 30642 Knob-Tuning or volume control knob-Package of 5 12695 Resistor -15,000 ohms, insulated, i watt (R13)- 11765 Lamp-Dial lamp-Package of 5 Package of 5 7766 Lead-A lead (ammeter end), complete with fe - 14166 Resistor -15,000 ohms, carbon type, 2 watt (R3). male section of fuse holder 12286 Resistor -56,000 ohms, insulated, I watt (R1)- Package of 5 30641 Lead-A lead (chassis end), complete with male section of fuse holder 12199 Resistor -270,000 ohms, insulated, 3 watt (R9)- Package of 5 30643 Lead-Shielded antenna lead (chassis end), corn - plete with female section of connector 12285 Resistor -470,000 ohms, insulated, I watt (R10)- Package of 5 30645 Mounting-Complete set of brackets, nuts, washers, and screws for mounting receiver 13730 Resistor -1 Megohm, insulated, I watt (R5) - 30644 Socket-Dial lamp socket and lead Package of 5 5024 Suppressor-Distributor suppressor 收音机爱 好者资料库 RadioFans.CN