General-Electric-Co-C420 电路原理图.pdf

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1、VOLUME R-18, MOST-OFTEN-NEEDED 1958 RADIO SERVICING INFORMATION GENERAL ELECTRIC Models C420 and C421 TO REMOVE SPEAKER Follow steps 1 through 5 as above. Remove the 4 hexhead screws from around speaker. This will remove the speaker and speaker grille. TO REMOVE CHASSIS 1. Remove volume and tuning k

2、nobs. 2. Unscrew alarm set indicator knob (Rear) 3. Remove back of cabinet, 4. Unsolder leads from speaker. 5. Remove the cabinet top. 3. Remove the cabinet bottom. Timer leads should remain connected,.as they are long enough to allow ijppoval of radio for repair. Connect Test Oscillator 12BA6, V3 g

3、rid (pin 1) .in series with a .05 mf. 12BE6, V2 grid (pin 7) in series with a .05 mf. Test Oscillator Setting Inductively Coupled to Antenna Ll Receiver Tuning Tuning Gang Open Approximately 600 KC. (minimum capacity) Tuning gang open Tune for max. signal Rock in With core Of Tl Adjust for Maximum Output Cores of 2nd I. F. Transformer T4 Cores of 1st I. F. Transformer T3 Recheck adjustment of T3 and T4 ClD Oscillator trimmer C1F, R.F. Trimmer C1B, Antenna trimmer cores of R. F. Transformer, Tl. Rock in with receiver tuning 收音机爱 好者资料库 RadioFans.CN