Zenith-Radio-Corp-4L40 电路原理图.pdf

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1、MODEL L401 CHASSIS 4L40 MANUAL OF 1953 MOST-OFTEN-NEEDED RADIO DIAGRAMS Model L401 chassis 4L4o Model K401, Chassis 4K40 is - * H similar, uses 1L6 converter 35 circuit. Alignment informa- tion on the next page. s . *=* CD _ n md h * m x -,. X; )Q o Z 0 K UJ UJ m 3$ - JP5 2 - Hi- 收音机爱 好者资料库 RadioFan

2、s.CN MANUAL OF 1953 MOST-OFTEN-NEEDED RADIO DIAGRAMS ALIGNMENT PROCEDURE Alignment Model L 401, Chassis 4L40, continued from the page at left. OPERA TION CONNECT OSCILLATOR TO DUMMY ANTENNA INPUT SIC. FREQUENCY BAND . SET DIAL TO TRIMMERS PURPOSE 1 Converter Grid .1 Mfd 455 Kc. BC 600 Kc. Adjust prt

3、.andsec. trimmers for max imum output. I.F. Alignment 2 Connects .1 mfd capacitor acroaa the generator output. Advance the generator output and place the capa citor approximately six incheafrom the receiver. 1600 Kc. BC 1600 Kc. Osc. T rim. C3 Set Oscillator to scale 3 1400 Kc. BC 1400 Kc. Ant. T ri

4、m. C2 Align Wavemagnet ZENITH RADIO Model L406, Chassis 4L42, continued on next page. The 4L42 chassis is an AC, DC or battery operated super heterodyne. The chassis is isolated from the DC circuit, and all measurements must be made from a common nega tive point. The most convenient place to reach t

5、his negative point is the negative side or container of the electrolytic. When the change-over Switch SI is in AC position, the DC resistance from chassis to any circuit must be almost in finite. If an circuit becomes grounded a hum will result. The I.F. transformers incorporated in this receiver ar

6、e of the new permeability tuned type. The advantage of an I.F. transformer of this type is its extreme stability under vari ous humidity and temperature conditions. The upper coil is the secondary and the lower the primary. When adjusting these I.F. transformers the tuning wrench 68-19 can be in ser

7、ted into the top slug, rotated until maximum output is obtained and then dropped down to the lower slug and the same operation repeated. IF Alignment: Remove the chassis from the cabinet and ar range the units so thet the wavemagnet can be connected. All the connections and adjustments can be made f

8、rom the top of the chas sis . C onnect a signal generator, through a .1 mfd. dummy antenna, to the converter grid and B-(com- of the speaker. Set the signal generator to 455 Kc. and ad just Pri. & Sec. of T1 & T2 for the maximum indication on the output meter. SW-RF Alginment: Set the generator to 1

9、6.1 me., open the gang and adjust trimmer CID for maximum output. Then close the gang, set the generator to 4.6 me. and adjust L3 for maximum output. Set the generator to 15.5 me. and tune in the signal and rock gang, adjusting CIA for maximum signal. Caution: Do not tune in the image which is 15.5

10、me. plus 2x the IF frequency. BC RF Alignment: Connect a two turn loop across the leads of the signal generator, loosely couple this loop to the wave- magnet. Set the signal generator and the dial pointer of the receiver to 1620 Kc. and adjust C1C oscillator trimmer to resonance. Set the signal gene

11、rator and dial pointer to 1400 and adjust C1B antenna trimmer tb resonance. Set the signal generator to 600 KC, turn the gang to approxi mately 600 KC, and then rock the gang and adjust, C1E trim mer for maximum output. To track the BC band during final alignment the chassis must be installed in the cabinet, the Wavemagnet installed in the normal position and the battery pack placed on top of the cab inet to simulate actual operating conditions. 收音机爱 好者资料库 RadioFans.CN