Emerson-Radio-and-Phonograph-Corp-120076B 电路原理图.pdf

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1、MANUAL OF 19S0 MOST-OFTEN-NEEDED RADIO DIAGRAMS EMERSON RADIO Model 605, Chassis 120076B See page 43 for schematic diagram. ALIGNMENT INSTRUCTIONS To position pointer, turn variable condenser fully closed ond set pointer to referenco mark en dial backplate ut the iow frequency end of the dial. Volum

2、e control should be set at maximum position. The output of tbe signal generator should be no higher than necessary to obtain an output readin tenunte the signal input Os alignment proceeds. Use en insulated alignment tool for eii adjustments. Use isolation transformer if available; otherwise connect

3、 a .1 mfd. condenser in series with iow side of signal generator te chassis. AM ALIGNMENT RADIO DIAL SETTING OUTPUT METER ADJUST REMARKS 1 1 mfd* High side to Pin 7 (grid) ef 12BA7. Low side to chassis. 455 KC Broadcast Timing condenser fully open. Across voice coiL A1, A2, (Trans. T4). A3, A4, (Tra

4、ns. T2). Adjust for maximum output. Reduce dummy antenna to .001 mfd. if isolation trans. Is not used. 2 Loop 1600 KC Broadcast Tuning . condenser Acrow vo.ee fully open, j cmL A5, (Trimmer cond. C6). Form loop of several turns of wire. Radiate signal into receiver loop. Adjust for moximum output. 3

5、 Loop 1400 KC Broadcast Tune for j Across voice max. output. coil. * A6, (Trimmer cond. C5). Adjust for maximum output. FM l-F and Disc. Alignment Using AM Signal Generator and VTVM DUMMY ANTENNA SIGNAL GENERATOR SIGNAL GENERA- COUPLING t TOR FREQUENCY BAND SWITCH POSITION RADIO DIAL SETTING CONNECT

6、 VTYM ADJUST REMARKS High side to Pin 1 (grid) ef 12BA6 2nd i.f (Y4). Low side to chasm. 10.7 me. (Unmodulated) Frequency modulation 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) ef 12B

7、A6 1st i-f (V3). Low side o chassis. 10.7 me. (Unmodulated) Frequency modulation Tuning con denser fully open. Connect d.c. probe to poiut A. Common to chassis. A8, A9, (Trans. T3). Adjust for maximum output. 3 4)1 mfd. High side to Pin 2 (osc. grid) of 12BA7 conv. (Y2). Low side to chassis. 10.7 me

8、. (Unmodulated) Frequency modulation Tuning con denser fully open. Connect d.c. probe to poiut A. Common to chassis. A10, All, (Trans. Tl). Adjust for maximum output. 4 .01 mfd. High side to Pin 1 (grid) of 12BA6 2nd i-f (V4). Low side to chassis. 10.7 me. (Unmodulated) Frequency modulation Tuning c

9、on denser fully open. Connect d.c. probe to point B Common to chassis. A12, (Trans. T6). Adjust for maximum output. 5 4)1 mfd. 10.7 me. (Unmodulated) Frequency modulation Tuning con denser fully open. Connect d.c. probe to point C. Common to chassis. A13, (Trans. T6). Adjust for zero output. Continu

10、e with FM r-f alignment. FM l-F AND DISC. ALIGNMENT USING SWEEP SIGNAL GENERATOR AND OSCILLOSCOPE. Use frequency modulated signal, with 60 cycle modulation aed 450 kc sweep. Use 120 cycle sawtooth sweep voltoge in oscilloscope for horizontal deflection. DUMMY ANTENNA SIGNAL GENERATOR COUPLING SIGNAL

11、 GENERA TOR FREQUENCY BAND SWITCH RADIO DIAL j POSITION SETTING CONNECT OSCILLOSCOPE ADJUST REMARKS 1 .01 mfd. High side to Pin 1 (grid) ef 12BA6 1st i-f (Y3). Low side to chassis. 10.7 me. (Unmodu lated). Frequency Tuning con- i modulation denser fully i open. Vertical input to Point A. Ground to c

12、hassis. A7, AB, A9, (Trans. T5 and T3). Adjust for maximum output (height) and symmetry as per i-f aiignmout curve shown (poge43). 2 .01 mfd. High side to Pin 2 Tosc. grid) of 12BA7 conv. (Y2). Low side to chassis. 10.7 me. (Unmodu lated). Frequency , Tuning con- modulation denser fully open. Vertic

13、al input to Point A. Ground to chassis. A10, All, (Trans. Tl). Adjust for moximum output (height) and symmetry as | per i-f alignment curve shown (poge43). 3 .01 mfd. High side to Plo 1 (grid) ef 12BA6 2nd i-f (Y4). Low side to chassis. 10.7 me. (Unmodu lated). Tuning con- Frequency denser fully mod

14、ulation open. Vertical inpntto Point C. Ground to chassis. 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 os per discriminator alignment curve (poge43). Continue with FM r-f ali

15、gnment. FM R-F ALIGNMENT DUMMY ANTENNA SIGNAL GENERATOR COUPLING SIGNAL GENERA TOR FREQUENCY BAND SWITCH POSITION RADIO DIAL SETTING CONNECT VTVM ADJUST REMARKS 1 150 ohm re sistor in series with each gen. lead. High side to FM ant. term. Low side to chassis. 108.0 me. (Unmodu lated). Frequency modu

16、lation Tuning con denser fully open (108.0 me.) Connect Lc. probe to point A”. Common to chassis. A14 (Trimmer cond. C8). Adjust for maximum output. 2 4 M 9 M 106.0 me. Frequency modulation Tune for maximum output. M Al5 (Trimmer cond. C7). Adjust for maximum output. 收音机爱 好者资料库 RadioFans.CN MANUAL OF 19S0 MOST-OFTEN-NEEDED RADIO DIAGRAMS EMERSON MODEL; 605 * for bandswitch in FM position only. RESISTANCE READINGS 收音机爱 好者资料库 RadioFans.CN