* These pages will be a work in progress for a while, there is a lot of content to create. each article is hand cleaned, straightened, sharpened and cropped. Then a bibliography must be maintained, as many represent incredibly valuable ephemera now digitized. Sometimes this involves multiple layers of copyrights. Please consider all of this work under copyright.
PPIE in his backyard
A period of Struggle
|1719 Ninth Avenue, San Francisco, California, USA||Otis Moorhead's home laboratory location|
|650 Mission Street, San Francisco, California, USA||Company formed, Aug 1915, occupying the 4th (top) floor|
|534-536 Pacific Street, San Francisco, California, USA||Sales office split abt Jun 1916 due to factory noise|
|165 Jesse Street, San Francisco, California, USA
||Factory moved to Jesse Street abt Feb 1917|
|638-640 Mission Street, San Francisco, California, USA||Before Incorporation Jan 1918, Factory moved to 4 floor bldg.|
Moorhead Laboratories, with its various names, rotating employees,and no evidence of securing any significant patents, represents a complicated story of persistence and ingenuity at all costs.. .
Confirmed tube brandings: "VT", "Marconi-Deforest", "Moorhead Laboratories"
Other Advertised tube brandings: "A-P", "Atlantic-Pacific" were only used for 2-in-1 models
First Reference Found: San Francisco Examiner: 23 Jul 1916, pg 26;
A classified ad shows "I.I. Davis" seeking Chrome & Manganese in any quantity, any form (534 Pacific Bldg)
Last Reference Found: Oakland Tribune: 26 Oct 1924, pg 38;
The Oakland Tribune reports on pending decision in the Deforest lawsuits involving the Marconi-Deforest-Moorhead contracts.
Estimated production dates: Jan 1916 to 1924