RCA-Victor-Co-Inc-Q22A 电路原理图.pdf

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1、MANUAL OF 1946 MOST POPULAR SERVICE DIAGRAMS COMPILED BY M. N. BE3TMAN, SUPREME PUBLICATIONS 收音机爱 好者资料库 RadioFans.CN MANUAL OF 1946 MOST POPULAR SERVICE DIAGRAMS Pointer for Calibration Scale.Improvis a pointer for lh cali bration seal by fastening a piece of wire to the gang-condenser frame, and ba

2、nd the wire so that it points to the 180* mark on the calibration scale whfrti the plates are fully meshed. Dial-Indicafor Adjustment.After fastening lh chassis in lh cabinet, attach the dial indicator to lh drive cable with indicator at lh 540 kc mark (the firsl mark on A band to lh left of 550). a

3、nd gang condenser fully meshed. The indicator has a spring clip for attachmont to the cable. Spread-Band Alignment.The most satisfactory method of align ing or chocking the spread-band ranges is on actual reception of short-wave stations of known frequency, by adjusting the magnet ite-core oscillato

4、r coil for each spread-band so lhal these stations come in al the correct points on the dial. Fn exceptional cases, when the set is being serviced in a location where the noise level is high enough to prevent reception of short wave stations, a test-oscillator may be used for alignment, but an extre

5、mely high degree of accuracy is required in the frequency set- tinas of the test-oscillaor, as a slight error will prodyce consider able inaccuracy on the spread-band dials. The frequency sellings of the test-oscillator may be checked by one or both of lh follow ing methods: 1. Determine the exact d

6、ial settings of the test-oscillator (for fre quencies at or close to the specified alignment frequencies) by zero-beating the test-oscillator against short-wave stations of known frequency. 2. Use harmonics of the standard-broadcast range of a test-oscil lator, first checking the frequency settings

7、on this rang by means of a crvstal-controlled oscillator, or by zero-beating against standard broadcast stations. When a test oscillator is employed for spread-band alignment, a final check should be made on actual recaption of shorl-wav sta tions of known frequency, and the magnetite-core oscillato

8、r coil for each band should be retouched so that the stations come in al the correct points on th dial. POVE- VOLUMC CONTROL , USTOP I 1 04 BOTTOM ADJ. 4SSKC IT- L=J Jgjsejfe U.MiK_ILSMC /fit c,J (% I ( ASMC 14 C4 C9C , 1 46DKC l9QOKCS ZS 115 BOTTOM k US TOP A0J.4S5KC / WOCTAF.AWC. LINE VOLTAOS t MW

9、lTCM ON 2MV UNIVSRSAL Lfi MOOSL9 NLV-*! OUTPUTmCT RCA MODUS Q22A & 032 * Chassis No. RC-507Mfr. No. 274 Connect th Steps Mgh side of Tun tost- th tst-osc. osc. to to SSK7 I F 1 grid in sris with .01 mid. Quiet 6SA7 1st Det. grid in sries with 455 kc A -B * 111 .01 mid. 11.8 me 25 M 138.5 15.2 me 17

10、Ant. lead Rpat stops 2 and 4 in sris with 300 15.2 me 10-13 M 156 ohms 9.5 me 91 M 156 9.5 me B 11.5 1,500 kc 28 Ant lead in sris with 200 600 kc A “ 150 mmf. Rpat stops 9 and 10 Adust th Range Turn radio following for switch dial to max. peak output L15 and L16 2nd I-F Trans. L13 and L14 1st I-F Tr

11、ans. LU (osc.)* Cl (ant.) CM (osc.)* L12 (osc.)* L10 (osc.)* C2 (ant) C7 (osc.)* C4 (osc.) C2 (ant) U (osc.) (Rock gang) * Us minimum capacity peak if iwo can be obtained. Check iraag lo determine that C14 has been adjusted to lh correct peak by luning receiver lo approximately 14.29 me (29) whr a w

12、eaker signal should be received. * if two peaks can be obtained use lh on obtained when th cor screw is farthest out (counter-clockwise). * peak at minimum capacity if two peaks can be obtained. NOTE: Oscillator tracks abov signal on all bands. Dial-Indicaior and Drive Mechanism R.F.WtfttNG OtAGRAM (BOTTOM VIEW) COMPILED BY M. N. BEITMAN, SUPREME PUBLICATIONS 收音机爱 好者资料库 RadioFans.CN 收音机爱 好者资料库 RadioFans.CN