Zenith-Radio-Corp-645L 电路原理图.pdf

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1、VOLUME R-25, MOST-OFTEN-NEEDED 1965 RADIO SERVICING INFORMATION ZENITH RADIO MODEL ROYAL 645L” CHASSIS 6LT45Z2 121-259 1ST I.F. (Continued on the next page, at right) 121-260 2ND I.F 121-266 DRIVER 121-267 OUTPUT 121:257 CONV. jyyf m: ItO -!j L- rl r9”ar560 JJ0 j 5K , f .02 T IVOUWC? V J-1 control 1

2、21-267 OUTPUT Jr ) I ,1, CIO JCIC- s 1 I 20 | 2D 6 D6 4 3D D4 3D / r J GROUND LUG / ALL VOLTAGES ARE D.C. UNLESS OTHERWISE SPECIFIED. ALL CONDENSERS ARE IN MICROFARADS UNLESS OTHERWISE SPECIFIED. DENOTES CHASSIS J_ SPEAKER IMPEDANCE 22 A AT 400 CPS. T2 2N0 I.F TRANSFORMER PNP TRANSISTORS ALIGNMENT P

3、ROCEOURE DRIVER TRANSFORMER- Input Signal Connect Inner Conductor Connect Outer Shield Operation Frequency From Oscillator To Conductor From Set Dial At Trimmers Purpose Oscillator To ONE TURN LOOSELY COUPLED TO WAVEMAGNET 600 KC Adj. TI,T2, T3 for maxi* mum output. For LF. Alignment Gang wide open.

4、 CIC Set Oscillator to dial scale. Gang Closed Adjust slug in T6 Set Oscillator to dial scale. CIA | Align loop aat. TRANSISTOR INFORMATION CHART D.R S.T. SWITCH ON VOLUME CONTROL J XL=. HVT T Tl 1ST I.F TRANSFORMER T3 3RD I.F TRANSFORMER Chassis Part No. Conv. 1st I.F. 2nd I.F. Crystal Diode Driver

5、 Output- Output Supplier 6LT4SZ2 Zenith Type E.I.A. 121-257 PNP 2N1526 121-259 PNP 2N1524 121-260 PNP 2N1524 103-44 121-266 PNP 2N406 121-267 Pair PNP PNP 2N408 R.C.A. 178 收音机爱 好者资料库 RadioFans.CN VOLUME R-25, MOST-OFTEN-NEEDED 1965 RADIO SERVICING INFORMATION LEGEND B-BASE C OLLECTOR E-EMITTER ANT S

6、ECTION GANG OSC SECTION GANG D t S T SWITCH ON VOLUME ONTROL 2700 U2 105-73 INTEGNET 121-267 OUTPUT iroooooo mnnjo Resistors and capacitors should be replaced by clipping out the defective part and neatly soldering in the new part. If a unit, such as the oscillator coil or I.F. trans former, is to b

7、e removed heat the mounting lugs with a pencil type soldering iron and move them away from the soldered connection with a long-nose pliers or metal pick. Continue heating the lugs and brush away the molten solder with a small stiff glue brush. Remove the defect ive unit by lifting it off the chassis

8、. Before inserting the new unit, be certain that the lug holes are open and free from solder. Forcing a lug against a solder filled lug hole may break the bond between the chassis base and the printed wiring. It is, therefore, necessary to exer cise care when replacing units. T1 95-2149 1st I.F. 12

9、-259 1st I.F. T2- 95-2033 2nd I.F. U3 10555 INTEGNET 121-260 2nd I.F. 5K VOLUME CONTROL rN. v DIODE T= * v U4 T3 1 T4 105-49 INTEGNET 95-2150 3rd I.F. TRANSFORMER 121-267 OUTPUT CHASSIS, WIRING AND COMPONENTS 95-2043 121-266 DRIVER DRIVER TRANSFORMER VIEWED FROM WIRING SIDE ZENITH RADIO Model Royal 645L, Chassis 6LT45Z2 (Continued from preceding page, at left) u-l 105-74 INTEGNET 121-257 CONV. T5 95-2148 OSC. 179 收音机爱 好者资料库 RadioFans.CN