Zenith-Radio-Corp-7AT43Z3 电路原理图.pdf

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1、VOLUME R-18, MOST-OFTEN-NEEDED 1958 RADIO SERVICING INFORMATION ftiMiwtr-r MODEL ROYAL 7001” CHASSIS 7AT43 & 7AT43Z3 LON-OFF SWITCH 8 VOLUME CONTROL EARPHONE JACK y RESISTANCE MEASUREMENTS When making resistance measurements in the circuit, it is most important to remove the transistors in the circu

2、it under test otherwise readings obtained will be incorrect. This is the direct result of a transistor acting as a diode. In addition to this, it is important to know the internal battery voltage of the ohm meter as well as battery polarity of the meter leads since incorrectly placing ohm meter lead

3、s across an electrolytic condenser with low working voltage may damage the capacitor due to exces sive reverse current or excessive voltage. CIA ANTENNA TRIMr CIC OSCILLATOR TRIM J/ l-59 o nKmatchco pubs aH) a & T2 2ND I.F TRANSJ T6 OSCILLATOR TRANSr- Tl 1ST I.F TRANS.- T3 3RD I.F TRANS.- TRANSISTOR

4、 & TRIMMER LAYOUT FOR 7AT43 121-22 121-70 121-71 U MIXER 1ST I.F. 2ND I.F. R-*-, Tl 3900 06 32 3900 c,2 I r niM,fr._1 .|0. iiiuwp._i cib M o a / VOLTAGE READINGS It is suggested that a VTVM with an excellent low range scale be used to measure all circuit voltages. All volt ages indicated on the acco

5、mpanying diagram have been measured under no signal conditions and a battery supply voltage of nine volts. Under these no signal conditions, a check can be made of the batteries. The total voltage should be nine volts. Use alignment table on page 182 for this model also. 121-60 DRIVER 121-59 OUTPUT

6、MATCHED PAIR 600 l-L, C20 10% “psome 1 I 12 V 1 121-59 OUTPUT MATCHED PAIR J_17 BATTERIES “ 6 REGb T2 r- 0 121-21 T/jf 0SC. ALL VOLTAGES ARE 0C UNLESS OTHERWISE SPECIFIED 0C VOLTAGES SN0WN ARE MEASURE0 WITH NO SIGNAL USING AN AC-DC OR VACUUM TU0E VOLTMETER SCHEMATIC DIAGRAM FOR 7AT43 * 121-61 OUTPUT MATCHED PAIR T V BATTERIES 1 6 EtfD Differences in schematic of Chassis 7AT43Z3. 185 收音机爱 好者资料库 RadioFans.CN