Held at: The Historical and Interpretive Collections of The Franklin Institute [Contact Us]222 N 20th St, Philadelphia, PA, 19103
This is a finding aid. It is a description of archival material held at the The Historical and Interpretive Collections of The Franklin Institute. Unless otherwise noted, the materials described below are physically available in their reading room, and not digitally available through the web.
Overview and metadata sections
D. G. McCaa (1882-1954) was a doctor and a pioneer in the field of radio engineering from the Lancaster, Pennsylvania area. He is best known today for his noise-reduction circuits in AM radio.
David Galen McCaa (1882-1954) was born in Ephrata, PA to Dr. David Jenkins McCaa and Eugenia R. (Bickham) McCaa. Like his father, McCaa became a doctor, graduating from medical school and joining the staff at Philadelphia General Hospital in 1903. In 1905 he set up his own practice in Lancaster, PA and married May Estelle Yeiser in 1906. They had one son, John Robert McCaa. From 1909 to 1914 he worked in his practice as an x-ray surgeon. While attempting to improve the x-ray machine, McCaa discovered something that inspired him to experiment with transmitting the human voice over great distances without the use of wires to carry electrical impulses.
Leaving his medical practice, McCaa became a radio research engineer. After much experimentation, in 1914 McCaa was able to make a radio call from a ship in the Atlantic Ocean to the New York Herald Tribune editorial office without the use of wires. He invented the first successful ship radio phone in 1915. He started his own business called McCaa Radio Co. McCaa died in 1954.
This collection consists of materials relating to the work of early radio pioneer D. G. McCaa from 1909 to 1930, including twenty-five assorted lab notebooks, patents and patent correspondence, and other related papers.
Throughout his most active period experimenting with early radio, 1909-1930, McCaa kept detailed notebooks, describing his progress on a daily basis. These notebooks make up the largest portion of this collection and make it possible to follow the evolution of McCaa's ideas. Other materials in the collection include the design and operation of his wireless broadcasting station from 1909 to 1914, the design of the McCaa Radiotelephone apparatus, use of the latter for shipboard radio communication as exemplified by a wireless log from the steamship "Tyler" of the Old Dominion Steamship Company in 1914, and patents and patent correspondence.
Summary descriptive information on this collection was compiled in 2014-2016 as part of a project conducted by the Historical Society of Pennsylvania to make better known and more accessible the largely hidden collections of small, primarily volunteer run repositories in the Philadelphia area. The Hidden Collections Initiative for Pennsylvania Small Archival Repositories (HCI-PSAR) was funded by a grant from The Andrew W. Mellon Foundation.
This is a preliminary finding aid. No physical processing, rehousing, reorganizing, or folder listing was accomplished during the HCI-PSAR project.
In some cases, more detailed inventories or finding aids may be available on-site at the repository where this collection is held; please contact The Historical and Interpretive Collections of The Franklin Institute directly for more information.
- The Historical and Interpretive Collections of The Franklin Institute
- Finding Aid Author
- Finding aid prepared by Sarah Leu and Jack McCarthy through the Historical Society of Pennsylvania's Hidden Collections Initiative for Pennsylvania Small Archival Repositories
- This preliminary finding aid was created as part of the Historical Society of Pennsylvania's Hidden Collections Initiative for Pennsylvania Small Archival Repositories. The HCI-PSAR project was made possible by a grant from The Andrew W. Mellon Foundation.
- Access Restrictions
Contact The Historical and Interpretive Collections of The Franklin Institute for information about accessing this collection.