Gus Fallgren, Al Hankinson and Dick Wright

Transistor Museum Historic Profile

Recognizing Significant Contributions to 20th Century Semiconductor History and Technology

Curator’s Introduction


The First “Transistor Powered”

Trans-Atlantic Amateur Radio Contact


Late in the evening of September 18, 1956, a clear sweet-toned continuous wave radio transmission was generated by a midget-sized homemade amateur radio transmitter operated by Gus Fallgren, W1OGU, in Chelmsford Massachusetts.  Almost instantaneously, this transmission was received and acknowledged by Bo Brondum-Nielsen, OZ7BO, a Danish radio operator located in Copenhagen.  To the amazement of the Danish radioman, Gus Fallgren explained that his signal, travelling over 3600 miles across the Atlantic ocean, was powered only by two tiny Raytheon germanium transistors. This contact is the first documented transatlantic ham radio transmission using transistor technology.  The original concept and development of the transmitter was done in 1956 by three Raytheon employees, Gus Fallgren, Al Hankinson and Dick Wright, and the subsequent success of the project was featured in key industry journals of the time.  This Historic Profile documents the original and historically important work done back in 1956 and, in addition, presents material resulting from recent Transistor Museum interviews with all three of the original transmitter developers.  



Radio & Television News was one of the most popular electronics industry publications in the 1950s, with a wide distribution to engineers, experimenters and amateur radio operators.  Shown above is the cover title block from the February 1957 issue of the magazine, which featured a three page detailed article on the transistor transmitter, written by Al Hankinson and Gus Fallgren.  At left is a cover page section from this issue showing Gus in action at his “radio shack”, using the transatlantic radio transmitter.  A careful look at the photograph will reveal the two small Raytheon transistors mounted on the top of the transmitter, and the single 6 volt black/red battery used for power.


TransAtlantic Transistors, Page 2

Gus Fallgren in 1956 with Transistor Transmitter

Photo Copyright © 1957 by Radio &TV News

COPYRIGHT © 2010 by Jack Ward.  All Rights Reserved.