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Atwater Kent Models 30, 33, 35, 48 and 49 Radio Service Data Sheet
May 1930 Radio-Craft

May 1930 Radio-Craft

Wax nostalgic about and learn from the history of early electronics. See articles from Radio-Craft, published 1929 - 1953. All copyrights are hereby acknowledged.

Interestingly, a couple models of this Atwater-Kent radio featured an untuned front end at the antenna interface, possibly because the adjustment range of the provided variable capacitor would not handle an extreme antenna impedance. With as basic as all the RF amplifier stages are, it seems maybe adding a second adjustable capacitor in parallel to facilitate a wider adjustment range would not have been too big of a cost burden compared to the advantage of tuning the input in the presence of all the EMI spewing from crappy electromechanical equipment and minimally filtered transmitters (it was the era of AM).

Atwater Kent Models 30, 33, 35, 48 and 49

These receivers are six-tube sets of the single-dial, battery-operated type. They are often referred to by their factory catalog numbers, to wit: Model 30, No. 8000; Model 35, No. 8100; Model 48, No. 9840; Model 33, No. 8930, Model 49, No. 9860. The models 33 and 49 have a tuned input (four tuned circuits); the models 30, 35 and 48 have an untuned input (three tuned circuits). Models 48 and Models 49 are code numbers showing that a gold-finished panel is used. Models 33 and 49 are so wired that R5 limits the current to V5 and V6 only while V4 is controlled by the additional variable resistor Rx. R in the first stage of these two circuits has the same value as equivalent resistors R1 and R2. C is the regular tuning condenser, in shunt to which is the circuit-balancing variable condenser Ca.

The purpose of the untuned antenna input of the 30, 35 and 48, shown in the larger diagram, is to eliminate the detuning effects of aerials of different constants. If it becomes necessary to change a variable-condenser bank, make certain that the pulleys turn easily on the shafts; if they do not because of a damaged condenser shaft, replace the entire condenser group.

Each belt must be arranged with the eyelets, which clamp the two ends together, at the bottom of the belt loop. Each belt has two small holes; one to fit over a pin on the dial-condenser pulley and the other to fit over the pin on the pulley which is controlled by that belt.

Arthur Atwater Kent

Atwater Kent was an American inventor, entrepreneur and manufacturer of radio equipment. He was born on December 12, 1873, in Cassopolis, Michigan and died on August 30, 1949, in Philadelphia, Pennsylvania. He was a pioneer in the development of radio technology and his impact on the industry is still felt today.

Kent began his career as an electrical engineer, working for various companies before starting his own business in 1918. He founded the Atwater Kent Manufacturing Company in Philadelphia, Pennsylvania, with the goal of producing high-quality radio sets for the public. The company quickly became one of the largest radio manufacturers in the United States, producing over one million radio sets between the 1920s and 1930s.

One of Kent's innovations was the development of the "breadboard" radio set, which was easy to assemble and repair. He also made use of more efficient components, such as high-voltage power supplies, which allowed his radio sets to produce better sound quality. His radios were also known for their beautiful wooden cabinets, which were handcrafted and came in a variety of styles and finishes to suit any decor.

Atwater Kent was a visionary who understood the potential of radio as a means of communication and entertainment. He was an advocate for the development of commercial radio broadcasting and he supported the establishment of the National Broadcasting Company (NBC) in 1926. This network helped to bring radio to a wider audience and it was a major factor in the growth of the radio industry.

In addition to his contributions to the radio industry, Kent was also a philanthropist. He supported a number of educational and scientific organizations, including the Franklin Institute, and he established the Atwater Kent Foundation, which provided grants for scientific research.

Posted September 21, 2016

Radio Service Data Sheets

These schematics, tuning instructions, and other data are reproduced from my collection of vintage radio and electronics magazines. As back in the era, similar schematic and service info was available for purchase from sources such as SAMS Photofacts, but these printings were a no-cost bonus for readers. There are 227 Radio Service Data Sheets as of December 28, 2020.

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Atwater Kent Models 30, 33, 35, 48 and 49 Radio Service Data SheetMay 1930 Radio-Craft

Atwater Kent Models 30, 33, 35, 48 and 49 Radio Service Data Sheet
May 1930 Radio-Craft