General-Electric-Co-670 电路原理图.pdf

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1、VOLUME R-16, MOST-OFTEN-NEEDED 1956 RADIO SERVICING INFORMATION MODELS GENERAL ELECTRIC 672 SENSITIVITY S STAGE GAINS AT 0.4 . LTV AC AT PIN S TON 0.4VAC ACROSS TJ - SECONDARY Q AOOV GENERAL INFORMATION The Models 670, 671, 672 and 673 are four-tube superheterodyne portable radio receivers, which op

2、erate either on self-contained batteries or from a power line source of 105 to 120 volts A-C or D.C. These models are very compactly made and Incor porate two plated circuit chassis; the smaller of which contains the power supply components. The front of the cabinet swings down and open, provid ing

3、easy accessibility to tubes and batteries. CHASSIS REMOVAL: The chassis Is easily removed by means of the following procedure. 1. Swing down cabinet front by grasping front at top edge under handle. 2. Remove tuning and volume control knobs by pulling straight off their shafts. 3. Remove the two sma

4、ll Phllllps-head screws from the top rear edge of the metal chassis mount ing bracket. 4. Slide chassis and bracket out of cabinet. 5. Remove bracket from chassis by removing the 1/4 mounting screw from the bracket. The power supply chassis Is removed from the cabinet by removing the four small hex-

5、head mount ing screws. The speaker Is mounted on the cabinet front and may be removed by removing the four speaker mount ing clips which secure the speaker to the four bosses on the Inside of the cabinet front. IMPORTANT: Care should be taken when replacing defective parts, to apply as little heat t

6、o term inals and connections as possible; as excessive heat will damage the plated wiring on the chassis boards. VOLUME CONTROL REPLACEMENT: The volume control, on-off switch, and control mounting bracket, are a combined assembly (Catalog No. RRC-367) and must be replaced as such. The chassis must f

7、irst be removed from the cabinet as described under CHASSIS REMOVAL and the control removed as follows: 1. Cut off the three control lugs and the four switch lugs. 2. Apply enough heat to the bracket mounting lugs at ene end of the bracket to allow that end to be pulled free of the board. 3. Follow

8、the same procedure with the two lugs at opposite end of bracket and remove the assembly. 4. Heat each lug remaining In the board only enough to push It out. 5. The new assembly can now be Inserted Into the holes left by the old one and soldered Into place. TO REPLACE A TUBE SOCKET: Cut the socket fr

9、ee by cutting all of the socket terminals at the chassis. One socket (V2) has a center terminal which must be unsoldered. Now, heat the pieces of terminals remaining In the board only enough so they may be pushed out. The new socket can now be Inserted Into the holes left by the old one and soldered Into place. BATTERY INSTALLATION: Place batteries In place as shown In the Tube and Battery location Illustration. Make sure the battery connections are well seated. 45 收音机爱 好者资料库 RadioFans.CN