More on the Crosley Book Condenser

BY JACK LOWE AND DAVE CROCKER
WEB EDITION

The following article begins with a letter from Jack Lowe to A.R.C. about the Crosley book condenser (A.R.C., June 1994). Dave Crocker clears up a bit of confusion about the condenser's origin. (Editor)

"This should be the last word on the Crosley book condenser. Over the years, there has been much speculation about the Crosley book condenser, such as, who invented it? The answer is that the inventor was none other than Hugo Gernsback. His invention was filed for patent on September 27, 1923. One of his many inventions, it was 'the only patent that ever brought me in any money,' said Gernsback.

"It was a variable condenser, comprised of a condenser plate, secured on the base, and a cooperating resilient plate -- means for flexing the resilient plate. In clear language, it was the compression condenser, now used universally as a trimmer to track the sections of a variable condenser gang. The device was sold to Crosley and was used as a book condenser in the Crosley Trirdyne radio."

Dave Crocker's COMMENTARY

There is often much confusion about Powel Crosley's use of the famous book condenser, and Jack's assumption is an example. In this article I would like to set the record straight and resolve this resurfacing mystery.

Figure 1. Patent drawing of Gernsback's compression condenser, prototype of today's trimmers. The main parts are: (19) fixed plate, (16) resilient plate, (25) adjusting knob, and (26) dial scale.

Figure 2. Powel Crosley's first book-type tuning condenser, the Type A, used in his early model receivers, was constructed mostly of wood.

PATENT DRAWINGS

Jack's description and Figure 1 illustration are correct in that the condenser shown was patented in 1923 by Hugo Gernsback. However, Crosley did not use this particular unit. Gernsback's design was used in such sets as the Connecticut Telephone and Electric Co.'s Sodion DR-6 receiver. It was a compression-type, which had some similarities to the book-type condenser.

Figure 3. The more familiar Crosley Type D book condenser with molded "mud" book plates.

Figure 6. Powel Crosley's patent drawing for his famous book condenser, filed on May 23, 1921.