Emerson-Radio-and-Phonograph-Corp-679B 电路原理图.pdf

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1、MANUAL OF 19S1 MOST-OFTEN-NEEDED RADIO DIAGRAMS Emerson Radio CHASSIS MODEL: 120116-B rc i L III O ! *5 K! o a * 2 2,s CQ OP W 收音机爱 好者资料库 RadioFans.CN MANUAL OF 19SI MOST-OFTEN-NEEDED RADIO DIAGRAMS ALIGNMENT INSTRUCTIONS, MODEL 679B, continued. EMERSON RADIO K-K- To position pointer, turn variable

2、condenser fully closed and set pointer to reference mark on dial backplote at.the low n!nn*1 outout reodino At* ! Volume control should be set of maximum position. The output ot the signal generator should be no higher thon necessary to obtain an outpu g. tenuate the signal input as alignment procee

3、ds. Use an insulated alignment tool for all adjustments. . _ Use isolation transformer if available; otherwise connect a .1 mfd. condenser in series with low side o signal genera AM ALIGNMENT DUMMY ANTENNA SIGNAL GENERATOR COUPLING SIGNAL GENERA TOR FREQUENCY BAND SWITCH POSITION RADIO DIAL SETTING

4、OUTPUT METER ADJUST REMARKS 1 .1 mfd. High side to Pin 7 (grid) of 12BE6. Low side to chasis. 455 KC. Broadcast Tuning condenser fully open. Across voice coil. Al,A2,(Trans- T4). A3, A4. (Trans. T2). Adjust for maximum output. Reduce dummy ontenna to .001 mfd. if isolation trans. is not used. 2 Loop

5、 1620 KC. Broadcast Tuning condenser fully open. Across voice coil. A5, (Trimmer cond. C6). of wire. Radiate signal into receiver loop. Adjust for maximum output. 3 Loop 1400 KC. Broadcast Tune for max. outpt. Across voice coil. A6, (Trimmer cond. CSI. Adjust for maximum output. FM l-F and Disc. Ali

6、gnment Using AM Signal Generator and VTVM DUMMY ANTENNA SIGNAL GENERATOR COUPLING SIGNAL GENERA TOR FREQUENCY BAND SWITCH POSITION RADIO DIAL SETTING CONNECT VTVM ADJUST REMARKS 1 .01 mfd. High side to Pin 1 (grid) of 6BJ6 2nd i-f (VS). Low side to chassis. 10.7 me. (Unmodulated) Frequency modulatio

7、n Tuning con denser fully open. Connect d.c. probe to point *A. Common to chassis. A7, (Trans. T5). Adjust for maximum output. 2 .01 mfd. High side to Pin 1 (grid) of 6BJ6 1st i-f (V3). Low side to chassis. 10.7 me. (Unmodulated) Frequency modulation Tuning con denser fully open. Connect d.c. probe

8、to point A. Common to chassis. A8, A9, (Trans. T3). Adjust for maximum output. 3 .01 mfd. High side to Pin 7 of 12AT7 eonv. (V2). Low side to chassis. 10.7 me. (Unmodulated) Frequency modulation Tuning con denser fully open. Connect d.c. probe to point “A*. Common to chassis. A10, All, (Trans. Tl).

9、Adjust for maximum output. 4 .01 mfd. High side to Pin 1 (grid) of 6BJ6 2nd i-f (VS). Low side to chassis. 10.7 me. (Unmodulated) Frequency modulation Tuning con denser fully open. Connect d.c. probe to point B. Common to chassis. A12, (Trans. T6). Adjust for maximum output. 5 .01 mfd. 10.7 me. (Unm

10、odulated) Frequency modulation Tuning con denser fully open. Connect d.c. probe to point C. Common to chassis. A13, (Trans. T6). Adjust for zero output, Continue with FM r-f alignment. :M l-F AN sweep. D DISC. ALI Use 120 cy GNMENT USING SWEI eie sawtooth sweep v P SIGNAL GENER oltoge in oscillosc h

11、TOR AND OSCILLOSCOPE. Use frequency mndulaied ope for horisontai deflection. signal, with 60 cycle modulation and 450 he vmni BANb iWiTCH POSITION RA6I6 bUL SETTING -CONNECT OSCILLOSCOPE ADJUST REMARKS i .01 mfd. High side to Pin 1 (gridl of 6BJ6 1st i-f (V3). Low side of chassis. 10.7 me. (Unmodu l

12、ated). Frequency modulation Tuning con denser fully open. Vertical input to Point A”. Ground to chassis. A7, A8, A9, (Trans. T5 and T3). Adjust for maximum output (height) and symmetry as per i-f alignment curve shown* 2 .01 mfd. High side to Pin 7 of 12AT7 of conv. IV2). Low side to chassis. 10.7 m

13、e. (Unmodu lated). Frequency modulation Tuning con denser fully open. Vertical input to Point “A*. Ground to chassis. A10, All, (Trans. Tl) Adjust for maximum output (height) and symmetry as per i-f alignment curve shown. 3 .01 mfd. High side to Pin 1 (grid) of 6BJ6 2nd i-f IV5). Low side to chassis

14、. 10.7 me. (Unmodu lated). Frequency modulation Tuning con denser fully open. Vertical input to Point C. Grounc to chassis. J_ A12, A13, (Trans. T6). Alternately adjust A12 for maximum amplitude and A13 for maximum straight ness of cross-over lines, with cross-over occurring at center of pattern as

15、per discriminator alignment curve. Continue with FM r-f alignment. FM R-F ALIGNMENT DUMMY ANTENNA SIGNAL GENERATOR COUPLING SIGNAL GENERA TOR FREQUENCY BAND SWITCH POSITION RADIO DIAL SETTING CONNECT VTVM ADJUST REMARKS 1 300 ohm re sistor in series with gen. lead. High side to FM ant. term. Low sid

16、e to chassis. 109.0 me. (Unmodu lated). Frequency modulation Tuning con denser fully open Connect d.c. probe to point “A”. Common to chassis A14 (Iron Core) Adjust for maximum output. I 2 if 106.0 me. Frequency modulation Tune for maximum ” j (Iron Core) output. 1 Adjust for maximum output. / 收音机爱 好者资料库 RadioFans.CN 收音机爱 好者资料库 RadioFans.CN