Magnavox-Co-2ST687 电路原理图.pdf

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1、VOLUME R-25, MOST-OFTEN-NEEDED 1965 RADIO SERVICING INFORMATION IS/lcigna MODELS 2ST686, 2ST687, 2ST690 (Material below and continued on the next three pages) The R207 Series chassis are AM-FM tuners using transistors throughout the entire circuit. These tuners are designed to operate in conjunction

2、 with an external audio amplifier which also provides the DC voltage necessary to operate the tuner. This DC voltage is dropped from a -31 VDC and regulated at -16VDC. The Sensitivity Control (R403) is used to adjust the point at which the diodes cut off. To set this control, tune the receiver off s

3、tation and adjust this control clockwise until the background noise just disappears. For reception of weak stations, it may be necessary to reduce this setting slightly. DIAL STRINGING GUIDE LENGTH REQUIREDv PLATES FULLY CLOSED,PULLEY CUT-OUT AT K OCLOCK. CORD LENGTH REQUIRED, SEE DETAIL I DETAIL I

4、-FASTEN THIS END SECURELY FOUR COMPLETE CCW TURNS LENGTH REQUIRED, APPROX 59-“- 57 收音机爱 好者资料库 RadioFans.CN VOLUME R-25, MOST-OFTEN-NEEDED MAGNAVOX R207 Tuner Diagram rL _ f TKI TI02_ L30I . Y I P 1 965 RADIO SERVICING INFORMATION I4.3vl -I5vj CI03 c, TI03 .01 T104 It mil 3600 Hi 13 270 CMC 3MFD CII3

5、 .1 RII2 CII4 270 .003 CM3 .1 “*-3 RU4 9100 ay. RII3 ieoo 5% 0106 6IPI FM Rf -n w -3-6V/p- I oioi- fmosL- 12 li3W+-n Ci33 3 vW0Vg-2 rv 收音机爱 好者资料库 RadioFans.CN VOLUME R-25, MOST-OFTEN-NEEDED 1965 RADIO SERVICING INFORMATION MAGNAVOX R207 Tuner Diagram, Continued T602 C4 41 X 13 C608 j lOMFO .4u -I3.6

6、V1 ,_SI_j2prT402 u Cw 43P4 EMITTER FOL R609$l9KC AMP 100 -4.2V C6II R624S +2.IV 1000? R625 O . vT ioo+bW jo+6,3V 0605 J 43P6 INDICATOR J OC AMP . OVI I C602 R60l J L60I f 660 _R3I0A = .033 MFD |7|J-?0- (-F-S - LOUDNESS 59 收音机爱 好者资料库 RadioFans.CN VOLUME R-25, MQ6T-OFTEN-NEEDED 1965 RADIO SERVICING INFORMATION MAGNAVOX R207 AM/FM Radio Tuner (Continued from preceding three pages) TREBLE BASS LOUDNESS FUNCTION TUNII SWITCH CHASSIS LAYOUT (TOP VIEW) TUNING TIMBRE SQUELCH ON-OFF SENS. (TOP) AUDIO BALANCE 1 (BOTTOM ) 60