1922 Jefferson Electric catalog

By Roger Russell

Copyright 1996-2004 by Roger Russell
All rights reserved
No portion of this site may be reproduced in whole or in part
without written permission of the author.

Bulletin No. 567

July 25, 1922

Radio Equipment

Amplifying Transformers
Vacuum Tube Socket
Grid leak
Grid Condenser

Wireless Transformers
Wireless Spark Coils

Jefferson Electric Mfg. Co.
426-430 S. Green Street
Chicago, Ill.

Amplifying Transformers

"These Amplifiers are designed especially for the new Tubes
and are the result of exhaustive tests of every kind."

"The Jefferson No. 45 navy Type Transformer is the most widely used Transformer in the country. Inherent capacity effects have been practically eliminated by our special method of winding and the use of No. 44 wire. A core of extremely light gauge Silicon Steel, especially rolled for this purpose tremendously increases the efficiency of the Transformer. The primary of the No. 45 Transformer is wound with 3900 turns of No. 44 wire, the resistance being approximately 1800 ohms; the secondary has 12,000 turns of No. 44 wire, the resistance being 8500 ohms."

"The No. 41 also is a very efficient Transformer. In fact, the only difference between the No. 41 and the No. 45 is that No. 40 wire is used in the No. 41 and No. 44 wire in the No. 45. This, of course, means that the No. 41 Transformer is a little larger and, consequently, a little less free of capacity effects. The No. 41 Transformer has a primary consisting of 4000 turns of No. 40 wire, resistance about 900 ohms; the secondary has 15,000 turns of No. 40 wire, resistance about 5000 ohms."

"Transformers are mounted in attractive nickel plated frames with genuine Bakelite panels which carry the Primary and Secondary Binding Posts. Each type of Transformer is furnished either mounted or unmounted."

No. 40--Unmounted Type
No. 41--Mounted Type
No. 44--Unmounted Type
No. 45--Mounted Type


A letter dated Aug. 28, 1922 from H. T. Moorman of Jefferson Electric to Weyrich & Hadraba, Plattsmouth, Neb. further describes the transformers.

"Answering your postal of August 14th, we beg to submit the following data in reference to our #41 and #45 Audio Frequency Transformers"




Ratio of Turns

Pri. 1100 ohms
Sec. 5350 ohms

2200 ohms
9700 ohms

Impedance at 1000 cycles

Pri. 79,000 ohms
Sec. 1.8 megohms

80,500 ohms
1.5 megohms

Short circuit current, 60 cycle, 220 volts impressed.

Pri. .144 amperes
Sec. .011 amperes

.064 amperes
.007 amperes

"We are enclosing our bulletin #567 covering Radio Apparatus of our Manufacture."

Vacuum Tube Sockets

"Any of the standard four-prong tubes can be used with the Jefferson Vacuum Tube Socket"

"The tube receptacle is constructed of sheet brass and is sufficiently flexible to allow for variations in the sizes of the vacuum tubes. Any standard tube is, therefore, readily and easily inserted. Turning through a small angle, it is held securely in place. The contact fingers are spring-tempered German silver, insuring smooth and positive action."

"The base of the socket is of sufficient depth to allow clearance between contact fingers and surface when used for table mounting. Screw holes are provided for mounting."

"The rugged construction and absence of breakable parts makes this socket practically indestructible."

No. 49 Jefferson Vacuum Tube Socket____$0.75

Grid Leak and Fixed Grid Condenser

"The Jefferson Variable Grid Leak can be mounted directly on the detector panel. The base is constructed of fibre and a pencil mark between the studs provides the variable resistance. Metal cover cap is finished in black satin enamel."

No. 55 Jefferson Grid Leak___$0.50

"Jefferson Grid Condenser No. 56 will fit directly on the studs of this grid leak. Jefferson Fixed Grid Condenser is .00025 M. F., the correct value for the new type Vacuum Tubes. Conductors are stamped from copper sheet and are insulated with glassine paper. Entire unit is encased and impregnated, and terminals are provided for mounting directly on the Jefferson No. 55 Grid Leak."

No. 56 Jefferson Fixed Grid Condenser___$0.25

Steel Base Switches

"Jefferson Steel Base Switches are metal throughout, and are suitable for all classes of low voltage work. Heat or the elements have no effect on them."

"These switches present a very handsome appearance. The base is black enameled, highly polished, and the jaws are of spring clip contact, which makes a positive electrical connection."



List Price

No. 1

Single Throw, plain handle


No. 2

Single throw, insulated handle


No. 3

Double Throw, plain handle


No. 4

Double Throw, insulated handle


Wireless Transformer

"This transformer is air insulated type, constructed to withstand a dead short circuit for some little time."

"Assembled in black enameled cast iron frames. Either side of the secondary windings may be grounded as the primary and secondary are thoroughly insulated from each other."

"Stock windings will operate on voltages ranging from 100 to 120 volts, 50 cycles to 133 cycles. 25 cycle or 220 volt windings are special."

"Wireless Transformers Made in All Sizes and Capacities"







1/2 K. W.

10,000 V.

20 lbs.


Wireless Spark Coils

"These coils are used in wireless work to step up the voltage and frequency of the current. They are designed to operate on dry cells or storage battery, and are guaranteed to give their rated spark length between needle points."

"The windings and condenser are so carefully balanced that arcing at contact points is practically eliminated, insuring long life to the points as well as absolute protection against sticking or freezing. The windings are very generously proportioned, insuring a spark which is heavy and energetic."

"The construction of the vibrator is exceptionally rugged and adaptable to heavy work. The points are made of the very best grade of tungsten."

"Jefferson induction coils will stand hard usage and their high efficiency insures economy in current consumption, which means long life to batteries. Made for either 6 or 12 volts, for operation on four or eight dry cells. Each coil is assembled in a dovetailed highly polished mahogany case, metal parts in brass."

No. 80

Half Inch Induction Coil


No. 81

One Inch Induction Coil


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Created by Roger Russell
All contents are copyright 1998-2004
by Roger Russell. All rights reserved