Galvin-Mfg-Co（Motorola）-7XM22 电路原理图.pdf

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1、MANUAL OF 19S2 MOST-OFTEN-NEEDED RADIO DIAGRAMS CHASSIS MODEL HS-303 72XM21 Motorola Chassis HS-218, used in Models 7XM21 and 7XM22, is similar to Chassis HS-303 covered by information be low ana on the next page. 79 收音机爱 好者资料库 RadioFans.CN MANUAL OF 19S2 MOST-OFTEN-NEEDED RADIO DIAGRAMS MOTOROLA Ch

2、assis HS-S03, Model 72XM21, continued from preceding page. tor output to a level which produces less than .40 volts across the voice coil, to avoid overloading the receiver. Set the bandswitch to the AM position. Turn the receiver volume control to maximum. STEP DUMMY ANTENNA GENERATOR CONNECTION GE

3、NERATOR FREQUENCY GANG SETTING ADJUST REMARKS IF ALld MENT 1. . 1 mf Grid of conv. 455 Kc Fully 1, 2, 3 & Adjust for maximum. V-2 (pin 7, opened 4 (IF cores) 12BA7) RF ALIGNMENT 2. . 1 mf Grid of conv. 1620 Kc Fully 5 Adjust for maximum.* v-2 (pin 7, opened (BC osc) 12BA7) 3. Across radia- 1400 Kc T

4、une in 8 Adjust for maximum. tion loop* signal (BC ant) 4. If, after the receiver has been aligned as above, it is found to be badly off calibration, it will be ne cessary to adjust oscillator core (7) as follows: connect the generator to the grid of the converter tube and, with the gang fully close

5、d, adjust core (7) at 535 Kc. It is advisable to repeat the oscillator ad justments at 1620 Kc and 535 Kc several times until the tuning range is correct. Core (7) has been pre-set at the factory and normally should require no retuning. tSIOADCAST BAND - IF & RF ALIGNMENT Connect the AM signal gener

6、ator as in chart be low, with 400 cycle, 30% modulation. Connect the output meter across the speaker voice coil. Throughout alignment reduce the genera- * If difficulty is encountered in tuning Connect generator output across 5 loops at least 12” apart. FM BAND . IF & RF ALIGNMENT Connect the signal

7、 generator as in chart below, with no modulation. Keep Throughout alignment reduce the signal gen erator output to a value which produces no more than a 5 volt rise above no signal voltage, to avoid overloading the receiver. trimmer (5), adjust trimmer (6) to K turn from tight, diameter, 5 turn loop

8、 and couple inductively to receiver loop. Set the bandswitch to the FM position. Except in step 2 below, connect the electronic voltmeter across resistor R-23 (15K) in the ratio detector stage. In step 2 below, connect two lOOK ohm resistors in series across R-23. Connect the electronic volt meter b

9、etween the volume control side of resistor R-24 (33K) and the junction of the two lOOK re sistors, with the low side of the meter at the lOOK resistors. STEP DUMMY ANTENNA GENERATOR CONNECTION GENERATOR FREQUENCY TUNER SETTING ADJUST IF ALIG NMENT 9, 11, 12, 13 & 14 (IF cores) 1. 1000 mmf Grid of co

10、nv. V-2 (pin 7, 12BA7) 10.7 Me Fully opened 2. RF ALIG 1000 mmf WMENT Grid of conv. V-2 (pin 7, 12BA7) 10.7 Me Fully opened 10 (ratio det sec) 270 ohms FM terminals on 1oop 87.5 Me Fully closed 15 (osc adj nut) 4. - - Fully closed 16 (RF adj nut) 5.- 270 ohms FM terminals on 1oop 90 Me Tune in signa

11、l 17 (RF tuning plug) 6. 270 ohms FM terminals on 1oop 105 Me Tune in signal 16 (RF adj nut) 7. - - REMARKS Adjust for maximum. Adjust for zero. (Connect meter as in step 6 above). Adjust for maximum. Turn counterclockwise until core is at bottom of pipe, then turn four turns clock- wise. Adjust for maximum. Adjust for maximum. Repeat steps 5 & 6 until no further adjustrment is ne cessary. See previous page for trimi7ier location charts. 收音机爱 好者资料库 RadioFans.CN