Emerson-Radio-and-Phonograph-Corp-120314 电路原理图.pdf

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1、VOLUME R-17, MOST-OFTEN-NEEDED 1957 RADIO SERVICING INFORMATION EMERSON RADIO Model 855, Chassis 120314 *Q5 06 AUOlO OUTPUT “I i DETECT, -UC|3 C13A lC3fl a* tL J R9 i BATTERY *,0 Sm 9 VOLTS -I EMERSON PT NO 815010 CALLED OFF FOR Q2 AND Q3 CAN BE EITHER TWO (2) - 2N46 Oft A ZNI45 ANO A 2N|47 TRANSIST

2、OR FOR REPLACEMENT PURPOSES HOWEVER, OUR PT NO 815010 WILL BE A 2N|46 TRANSISTOR NOTES * At IF ONE OF THESE TRANSISTORS Q5 OR 06 BECOMES DEFECTIVE REPLACE BOTH OF THEM WITH A NEW MATCHEO PAIR. Q-3 2 NO I. F AMP. RESISTANCE READINGS o-2 o-* o TURN SET OFF* THEN REMOVE ALL TRANSISTORS BEFORE TAKING RE

3、SISTANCE READINGS I ST I F AMP CONVERTER RESISTORS IN OHMS (MiOOOl. CAPACITORS IN MfDS UNLESS OTHERWISE NOTED AUOlO OUTPUT MATCHED PAIR SYMBOL TERMINAL B TERMINAL C TERMINAL E_ RESISTANCE READINGS SHOWN ABOVE (N OHMS UNLESS OTHERWISE SPECIFIED Voltages indicated are pasitive d.c., resistance is ohms

4、. Measurements made with valtahmyst ar equivalent. All measurements taken between paints and chassis, BATTERIES EVEREADY NO 276 9 VOLT- OR EOUIV. ; / FOR SINGLE BATTERY OPERATION, _ PLACE BATTERY IN THIS POSITION. *NOTE IF ONE OF THESE tranSiSTORS 05 OR 06 BECOMES DEFECTIVE REPLACE BOTH OF THEM WITH

5、 A NEW MATCHED PAlR ALIGNMENT INSTRUCTIONS Volume control should be at maximum; output of signal generator should be no higher than necessary to obtain on out put reading with a 30% audio modulated R.F. Use an insulated alignment screwdriver far adjusting. DUMMY ANTENNA SIGNAL generator COUPLING Hig

6、h side to junc tion of L-l & C-2. Low side to chassis. Use a loop set per pendicular and about 20” from center of bar loop ant. in set. SIGNAL RADIO GENERATOR DIAL OUTPUT FREQUENCY SETTING METER ADJUST Tuning con denser fully open. Adjust for maximum output starting with T3. Fashion loop of several

7、turns of wire and radiate signal into bar loop of re ceiver. Adjust for maxi mum output. Adjust for maximum output. Osc. Rock the variable cond. slug in each side of 600 KC L-2 while adj. osc. slug for maximum response. C-3A If readjustment is neces- Osc. sary repest steps 2 to 4 trimmer until no fu

8、rther improve ment is noted. NOTE: C-3A is the oscillator trimmer capacitor, physically located an the bottom side of the tuning copacitar when the chassis is mounted in its case. Bath C-3A and C-2A can be reached through cutouts in the antenna mounting board. C-3B is the alternate oscillator trimmer capacitor and is factory odjusted far minimum trimmer capacity requirements. 29 收音机爱 好者资料库 RadioFans.CN