RCA-Victor-Co-Inc-RC-1060-OR-A 电路原理图.pdf

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1、MANUAL OF 1949 MOST-OFTEN-NEEDED RADIO DIAGRAMS 收音机爱 好者资料库 RadioFans.CN MANUAL OF 1949 MOST-OFTEN-NEEDED RADIO DIAGRAMS DrA/irTnP 8R71, 8R74, 8R75 8R72, 8R76 y Chassis No. RC-1060 Chassis No. RC-1060A Alignment Procedure CORRECT ALIGNMENT OF THE FM BAND REQUIRES THAT THE AM BAND BE ALIGNED FIRST Ali

2、gnment Indicators: An RCA VoltOhmyst or equivalent meter is necessary for measuring developed d-c voltage during FM alignment. Connections are specified in the alignment tabulation. An output meter is also necessary to indi cate minimum audio output during FM Ratio Detector alignment. Connect the ou

3、tput meter across the speaker voice coil. The RCA VoltOhmyst can also be used as an AM alignment indi cator, either to measure audio output or to measure a-v-c voltage. When audio output is being measured the volume control should be turned to maximum. Signal Generator: For .all alignment operations

4、 connect the low side of the signal generator to the receiver chassis. The output should be adjusted to provide accurate resonance indication at all times. If output measure ment is used for AM alignment the output of the signal generator should be kept as low as possible to avoid a-v-c action. The

5、FM i-f alignment may be checked hy means of an FM sweep generator and cathode ray oscilloscope. Connect the output from the sweep generator, which is set to 10.7 me., to the mixer grid (6J6 Pin No. 5), low side to chassis. Disconnect the 2 mfd. capacitor C33 from the Ratio Detector circuit. Connect

6、the high side of the oscilloscope to the junction of R25 and R26, low side to chassis. Adjust the sweep generator and oscillo scope to obtain the response curve. The Ratio Detector characteristic may be viewed by connecting the oscilloscope across the volume control R14. Capacitor C33 should be re-c

7、onnected before checking the Ratio Detector characteristic. AM Alignment RANGE SWITCH IN BC POSITION 1060A t Use alternate loading. Alternate loading involves the use of a 47,000 ohm resistor to load the AM plate winding while the AM grid winding of the SAME TRANSFORMER is being peaked. Then the gri

8、d winding is loaded with the resistor while the plate winding is peaked. Only one winding is loaded at any one time. Remove the 47,000 ohm resistor after T3 and T2 have been aligned. Oscillator frequency is above signal frequency on both AM- and FM. FM Alignment RANGE SWITCH IN FM POSITION- CONTROL

9、MAXIMUM - VOLUME Steps Connect high side of sig. gen. to Sig. gen. output Turn radio dial to Adjust for peak output C3 in series with .01 mfd. 455 kc. Quiet point at low freq. end. AM windings.f T3 bottom core (sec.). T3 top core (pri.). 2 AM windings.f T2 top core (sec.). T2 bottom core (pri.). 3 “

10、A” terminal of terminal board at rear of chassis in series with 220 mmf. 1400.kc. 1400 kc. C13 osc. C4 ant. 4 600 kc. 600 kc. L4 osc. (Rock gang.) 5 Repeat Steps 3 and 4. Steps Connect high side of sig. gen. to Sig. gen. output Turn radio dial to Adjust for peak output 1 Connect the d-c probe of a V

11、oltOhmyst to the negative lead of the 2 mfd. capacitor C33 and the .common lead to chassis. Turn gang condenser to max. capacity (fully meshed). 2 Pin 1 of 6AU6 in series with .01 mfd. 10.7 me. modulated 30% 400 cycles AM (Approx. .05 volt). T4 top core for max. d-c voltage across C33. T4 bottom cor

12、e for min. audio output.* 3 10.7 me. Adjust to provide 2 to 3 volts indi cation on VoltOhmyst during aiignment. Max. ca pacity (fully meshed). FM wlndings.ft T3 top core (sec.). T3 bottom core (pri.). 4 FM ant. term, in series with a 300 ohm resistor. (Remove ant. lead from “FM” term.) FM wlndings.f

13、t T2 top core (sec.). T2 bottom core (pri.). 106 me. 106 me. L2 osc.* C2 ant. Set C2 at max. capacity while adjusting L2. D 90 me. 90 me. Ll ant* (Rock gang.) D Repeat Steps 5 and 6 until fnrther adjustment does not improve calibration. * Two or more points may be found which lower the audio output.

14、 At the correct point the minimum audio output is approached rapidly and is much lower than at any incorrect point. tt Align T3 and T2 by means of alternate loading as explained under AM alignment. Use a 680 ohm resistor instead of a 47,000 ohm resistor and load the FM windings. * Ll and L2 are .adj

15、ustable by increasing or decreasing the spacing between turns. TOP 10.7 MC sec. BOT. 455 KC SEC. TOP 455KC PRI. BOT. 10.7MC PRI. 1ST. |.F. TRANS. TOP 10.7 MC SEC. BOT. 10.7MC PRI. TOP 455KC SEC. BOT. 455 KC PRI. C4 1400KC AM ANT LI F.M. ANT. COIL MIXER AND OSCILLATOR L2 FM OSCILLATOR COIL CI3 1400KC AM OSC. C4,C2 $ CI3 ACCESSIBLE FROM UNOERSIDE OF CHASSIS. 收音机爱 好者资料库 RadioFans.CN