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McCulloch Company
McColloch was a tube manufacturing company that was known for their AC tube prduced around 1925 that had no filament and illiminated the need for a storage battery.
Popular Radio magazine, published by Popular Radio, Inc., New York, Vol. 7, No. 6, June 1925, p. 10, http://www.americanradiohistory.com/Archive-Popular-Radio/Popular-Radio-1925-06.pdf (03/04/2015)