Jesse French Export Co. Junior Model G Schematic

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Product Information:
Model:Junior Model G
Manufacturer:Jesse French Export Co.

Schematics Content:

Page 1:

NOTE: - (A) VOLUME CONTROL (B) VOLUME CONTROL (C) SWITCH
ARE ONE UNIT (7777 VOLUME CONTROL) CONTROLLED BY ONE KNOB

JUNIOR MODEL G

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Radio Frequency Coils;
The R.F. Coils are of the high reactance type, accurately matched with the condensers.
There are two types of coil sets as well as two types of condenser gangs, and are designated by the markings as follows:
A. The coils used first with precise type condensers, are wound with 116 turns, space wound, and have no color designations on tubing.
B. No. 78297830. These coils used with precise condensers, are wound with 122 turns, space wound and have a red mark of paint on base of tubing.
C. No. 8010...- 8011. These coils used with General instrument condensers, have 126 turns, space wound, have a marking of white paint on base of tubing. Positions:
Coils No. 80107829. The first R.F. coil is located at the front of chassis and is not interchangeable with the second and third R.F. coils.
Coils No. 8011-7830. The second and third R.F. coils are interchangeable and are located in their respective places.
The first R.F. coil differs from the others, as it does not have a choke bucking coil inside of the tubing as the others.
Coil cans are very essential to aid selectivity and reduce interference. The Condenser Gang:
The tuning condensers are graded in three types. The condensers can be defined as follows: The first precise type, have no extended shields between the condensers.
No. 7832. The second precise type have two shields extending between the center and outside condensers.
No. 7872. The general instrument type have four shields and can be easily distinguished from the others.

VOLTAGES Referring to the Circuit Diagram, the following voltages are given throughout the circuit using straight A.C. or D.C. meters.
CHECK FROM GROUND OF CHASSIS TO POINT DESIGNATED. GROUND IS NEGATIVE. POINT DESIGNATED IS POSITIVE. SET VOLUME CONTROL AT MINIMUM. SET CHASSIS ON ONE END WITH BOTTOM IN VIEW. Use 600 volt D.C. meter - 1000 ohms per volt.
Rectifier filament or choke No. 7825 (beginning). 440 volts
Choke No. 7825 (ending) - . 390 volts
245 power tube plate or choke No. 7735. 368 volts
Use 300 volt D.C. meter 1000 ohms per volt.
Detector plate or resistor No. 7785 (ending) 48 volts
R.F. Plate or red wire of condenser No. 7015. 242 volts
245 grid or resistor No. 7785 (ending). 48 volts
Detector grid or green wire of condenser No. 7879 22 volts
Detector cathode or resistor No. 7786. 12 volts
R.F. cathode or black wire condenser No. 7015.. 2 volts
R.F. Screen Grid at red wire volume control or at Resistor No. 7783 (end)... 120 volts

USING A WESTON SET TESTER MODEL 537
Volume control set at maxim.

SPEAKER SERVICING.
The speaker color chart and the respective wiring connections. As follows: Chassis connections:
A. Yellow No. 4 goes to ground of set.
B. Black No. 3 goes to center tap of 245 tube filament, and resistor No. 7784.
C. Black No. 1 goes to No. 7989,500 ohm resistor and grid return of detector, at R.F. coil.
D. Red No. 2 goes to No. 7782, 10,000 and 7785 resistors.
E. Red No. 5 goes to plate of 245 or No. 7735 choke coil.

SPEAKER CONNECTIONS:
A. Yellow No. 4 goes to speaker ground.
B. Black No. 3 goes to speaker field.
C. Black No. 1 goes to speaker field.
D. Red No. 2 goes to output transformer.
E. Red No. 5 goes to output transformer.

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