Allen-Bradley Resistors Advertisement
December 1931 QST

Allen-Bradley has been making resistors for a long time, as evidenced by this advertisement from the December 1931 edition of the ARRL's QST magazine. From my earliest days in electronics in the 1970s, I remember using their products in hobby projects and then later in professional applications. Rockwell Automation now owns Allen-Bradley, so if you want historical information, you will have to do a search for pages like this one. According to Wikipedia: "The company was initially founded as the Compression Rheostat Company by Dr. Stanton Allen and Lynde Bradley with an initial investment of $1,000 in 1903 ($26,838 in 2021 money wrt 1913). In 1910 the company was renamed the Allen-Bradley Company."

Allen-Bradley Resistors Advertisement

Allen Bradley Resistors Advertisement in December 1931 QST Magazine

Here is the text of the advertisement:

Stop Interference on Radio-Equipped Cars With Bradley Suppressors

No Shielded Ignition Cable Needed

Bradley Suppressors are special solid molded resistors used by prominent car manufacturers to provide individual resistors for each spark plug and for the common cable to the distributor on radio-equipped can.

They increase the resistance of the high tension ignition system and minimize the disturbing oscillations in the ignition circuit which interfere with the radio receiver in the car. When used with suitable bypass condensers in other parts of the circuit, shielded ignition cables are unnecessary.

They do not affect the operation of the motor. The sturdy construction of Bradley Suppressors adapts them for the severe service in which they are used. Heat and moisture and age have no effect upon their performance. They are the last word for motorcar radio.

The Bradleyometer is a potentiometer with approximately fifty solid resistance discs interleaved between metal discs.

Bradleyunits are solid molded resistors unaffected by temperature, moisture or age.

Their accurate calibration, great mechanical strength and performance make them ideal for providing correct C-bias, plate voltage, screen grid voltage and for use as grid-leaks and as fixed resistors in resistance-coupled circuits.

All units are color-coded to meet any radio set manufacturer's specifications.

The total number of discs can be arranged in accordance with any resistance-rotation curve.

One or more Bradleyometers can be arranged to operate with one knob. Mixer controls, T-pad and H-pad attenuators and other complex controls can be provided.

ALLEN - BRADLEY CO.

106 W. Greenfield Avenue, Milwaukee, Wisconsin

ALLEN - BRADLEY RESISTORS

Produced by the makers of Allen - Bradley Control Apparatus

Posted April 7, 2021
(updated from original post on 12/18/2012)