Electro Importing Co. 1/2" radio spark coil
date: label: date made
content: ca 1912
name: label: maker
content: Electro Importing Co.
notes: label: Description (Brief)
content: Marking: plate reads: "1/2 inch / Bull Dog / Spark Coil / E.I. Co., N.Y." Instruction label on side of unit. Manufacturer states that this model was a French double spring vibrator with double adjustment. Two binding posts on top are connected to a suitable spark gap. Unit designed for use in small wireless telegraph transmitters with a range of wavelengths 1/4 to 3/4 of a mile. An external spark gap is required. Reference: Electro Importing Company Catalog, 1912, pages 63-64.
label: Location
content: Currently not on view
setName: label: See more items in
content: Work and Industry: Electricity
creditLine: label: Credit Line
content: from Franklin Wingard
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: EM.320937
label: accession number
content: 241556
label: catalog number
content: 320937
objectType: label: Object Name
content: spark coil
physicalDescription: label: Measurements
content: overall: 6 in x 10 in x 5 1/2 in; 15.24 cm x 25.4 cm x 13.97 cm