has been making resistors for a long time. 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
Allen-Bradley, so if you want historical information, you will have
to do a search for pages like this one, which shows an advertisement
from the December 1931 edition of the ARRL's QST magazine. According
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. In 1910 the company was renamed the Allen-Bradley
December 1931 QST
These articles are scanned and OCRed from old editions of the
ARRL's QST magazine. Here is a list of the
QST articles I have already posted. All copyrights (if any) are hereby acknowledged.
See all available
Allen-Bradley Resistors Advertisement
Allen Bradley Resistors Advertisement
in December 1931 QST Magazine
Here is the text of the advertisement:
Interference on Radio-Equipped Cars With Bradley Suppressors
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.
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.
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
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
106 W. Greenfield Avenue, Milwaukee, Wisconsin
ALLEN - BRADLEY
Produced by the makers of Allen - Bradley Control Apparatus