Tuning Condenser

RADIO AGE
The Newsletter of the Mid-Atlantic Antique Radio Club

Volume 31

February 2006

Number 2

Atwater Kent - Variable Condensers
BY

RAY THOMPSON AND LEIGH BASSETT

© 2006 BY RAY THOMPSON AND LEIGH BASSETT, PHOTOS © 2006 BY LEIGH BASSETT

[Normally Radio Age uses modern terminology, e.g., "capacitors" rather than "condensers," but in this case, authors Thompson and Bassett felt it was more appropriate to use the term prevalent in the era of the devices described in the article, and I honored that request. This is Part 5 of a series of articles on Atwater Kent by these authors, the first four of which appeared in Radio Age for May, July, October, and December 2005. -Editor]

Introduction
Tuning condensers first appeared in AK factory-built radios on September 7, 1923 with the introduction of the Model 8, part # 4325 (only 17 made) and the Radiodyne 10, part # 4340. This was two years after AK started making radio components. Why so long, considering most of the competitors were using tuning condensers? Possibly because Mr. Kent’s factory had already developed expertise in the production of automotive coils, so inductive tuners were a logical choice. Initially there were few broadcast frequencies in use, and inductive tuning worked just as well as capacitive tuning over this narrow range. As radio became more popular, more frequencies were added, and the limitations of inductive tuning became apparent. At this point AK joined the rest of the industry in using capacitive tuning. Despite the fact that
Figure 5-1. Type E tuning condenser # 4117.

AK was slow in using the condenser tuning units for its factory-built sets, individual parts were made available to homebrewers and experimenters much earlier. This
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Figure 5-2. Rear view of Type E tuning condenser, showing jeweling pattern and ground clip. (Continued from page 1)

Figure 5-4. Type P tuning... [continues]

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