Philco-Radio-and-Television-Corp-M-1688 电路原理图.pdf

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1、VOLUME R-25, MOST-OFTEN-NEEDED 1965 RADIO SERVICING INFORMATION PHILCO Models M-1666, M-1669, M-1680, M-1688, M-1689, M-1704 (Circuit diagram and other information on pages 122-123) VR51 V10 VR33 V8 VR52 V8 VOLUME B 6AV8 pq .TREBLE I2AX7A rva BASS 12AX7A PQ BACKGROUND PHASE IN V |t AM Alignment - A.

2、 Connect VTVM across center output transformer B. Use 30% modulation on generator for AM alignment. C. Proceed with alignm nt steps as illus trated in alignment chart. 4. For FM Alignment - A. Connect FM generator, through a 72 ohm to 300 ohm matching network, to antenna terminals. B. Alignmen : is

3、to be made in FM position. DO HOT USE FM/AFC position. C. Use 75 kc sweep deviation for FM a- lignment. D. Keep generator output as low as possible throughout FM alignment procedure. STEP 2 (AM| STEP A IAMI STEP M AM i STEPS IS2149SKC) f*A - TOP-MAX.I i SANA FULLY |OANO FULLY STEPWS30KCI ADJ BOT-MAX

4、 CLOMC-AJJ OFEN; AM TFP4ISViKCt au vf TO MAX OUT TO MAX OUT 6CN M- KC1 - ?5._- 555 KC 1*30 KC GANG SET TO 1500KC ADJ TO MAX OUT I5Q0KC STEP KAMI ADJ TOP-MAX AOJ BOT- MAX 455 KC ?=oJw l vsfii/- - 0 /KDfe 1 tlliS; LRlO, STEP 4 (SEE NOTED STEP 2 (FM) ADJ TOP MAX AOJ BOT-MAX K)TMC STEP I (FM) ADJ TOP-MA

5、X ADJ BOT-MAX 107 MC STEPS I B 2(FM| TO PIN I OF VS STEP 3 ONLY NOTE i 10 ?mc Signal UOkc. deviation. Readjust all cores except top of L3 for maximum inearity of S curve and maximum output* SET VTVM FOR CENTER SCALE ADJ TOP-OVQ.C AOJ BOT MAX 10-7 MC Alignment Procedure Chart AM-FM Tuner 121 收音机爱 好者资

6、料库 RadioFans.CN VOLUME R-25, MOST-OFTEN-NEEDED 1965 RADIO SERVICING INFORMATION PH ILCO V6A V6B RF AMP FM OSC t/2 6C9 1/2 6C9 MODELS M-1666, M-1669, M-1680, M-1688, M-1689, & M-1704 AMPLIFIER & TUNER (See page 121 for other data) ClT-i-7 TlT FM ANTENNA C4B C4| 22 T3T. oouL anrr -CIO fTioov .01 sL 1

7、LI AFC 6. 10Jmc_ .tch/ 1 SWITCH SHOWN IN OFF POSITION Amplifier and Tuner Schematic Diagram 122 收音机爱 好者资料库 RadioFans.CN VOLUME R-25, MOST-OFTEN-NEEDED 1965 RADIO SERVICING INFORMATION PH MODELS M-1666, M-1669, M-1680, M-1688, M-1689, M-1704, & M-1741 AMPLIFIER & TUNER (Continued) I R6 Tv-1 L3 JO. 7M

8、C _ IOOK -L oi L-r+- 1 ft- r 4,05 | . R5 -0047 | I 2.2 MEG J.CI7 -Lc r r AM-FM TUNER SW1 BACKGROUND SWITCH V9B PREAMP- 1/2 I2AX7A L. H. EXTERNAL SPEAKERS C63 R73 330 1_1 L.0022 I f 47K I VR5I -iLOUONESS 2.0 MEG x3R20K5 - CS7 j = .0033 I VR53 TREBLE 500K iK N3 R75 evE |VR54 3.3MEG M MEGi (/C6 LINE VOLTAGE MAINTAINED AT I20VAC. FUNCTION SWITCH SET TO PHONO POSITION EXCEPT WHERE SPECIFIED. FUNCTION SWITCH SET TO FM- STEREO POS. A FUNCTION SWITCH SET TO AM POS. 123 收音机爱 好者资料库 RadioFans.CN