Galvin-Mfg-Co（Motorola）-GV-701 电路原理图.pdf

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1、VOLUME R-19, MOST-OFTEN-NEEDED 1959 RADIO SERVICING INFORMATION MOTOROLA MODEL GV-701 TRANSISTOR CURRENT ADJUSTMENT - After replac- ing a transistor, the collector current must be adjusted to insure proper operation of the output stage* Adjustment of the collector current must be made within one min

2、ute after the receiver has been turned on - before it has time to warm up. If the receiver is warm from operation, it will have to be cooled before adjusting the collector current. A. Set R-21 to maximum resistance position (fully coun ter-clockwise when viewed from the wiring side) so- that the new

3、 transistor does not draw excessive collector current and run away”. B. Unsolder output transformer (T-4) black lead and grounded speaker lead from chassis; connect the two leads together. Be sure speaker is connected while making ad - justment; volume control must be set to minimum. Connect the pos

4、itive side of a 0 -1. S amp DC ammeter to the two leads just removed and the negative side to chassis. The meter used must have an internalresistance of .05 ohms or less; if higher, meter will act as a current limiter and cause an incorrect adjustment. C. Adjust R-21, within one minute, after turnin

5、g on a cold receiver for a total collector current reading of 160 ma with 12.6 volts input to receivers A” lead. Resolder two leads to chassis after adjustment. NOTE: Two values of receiver input voltage are given as a convenience to service personnel to accommodate different power sources. The sche

6、matic total col lector current value of 200 ma is stated with 14 volts DC input to receivers A lead. POWER TRANSISTOR INSULATOR - When replacing a power transistor or power transistor insulator, be sure to coat both sides of insulator with DC-4 grease (Motorola Part No. 11M490487) to insure proper h

7、eat dissipation. TO SIGNAL generator L-T-J! OCt *0. * *0213-0 DUMMY ANTENNA DETAIL PLUG TO FIT RECEIVER . ANTENNA RECEPTACLE TO RECEIVER =3Z=-* ANTENNA - RECEPTACLE ETAL SHIELO CAN MUST BE ATTACHEO TO PLUG hex ALIGNMENT - TOOL BOTTOM 1 II LI IF ALIGNMENT DETAIL ANT CORE RF CORE OSC TRIM 1200 KC 1200 KC 1610 KC | J ANT TRIM OSCCORE / RF TRIM 1610 KC 1200 KC 1 1610 KC , 0 0 00 0 I. C Q O O G O (, C O O o O - o o f r o O g O f r- O G J u O uurij uu ; n| o j amt ,_I j ljJ RECEPT FRONT VIE* j 1ST IF 262.5 KC G2N0IF 2625KC ALIGNMENT POINT LOCATIONS DETAIL n | inn 75 收音机爱 好者资料库 RadioFans.CN