2599-C, Type B Western Union voice frequency carrier system
name: label: Collection Creator
content: United Telegraph Workers.
label: Collection Creator
content: Western Union Telegraph Company
setName: label: See more items in
content: Western Union Telegraph Company Records
label: See more items in
content: Western Union Telegraph Company Records / Series 15: Engineering Department Records / 15.6: Specifications for Western Union
unitdate: label: Date
content: 1933
container: label: Container
content: Box 538, Folder 11
dataSource: label: Archival Repository
content: Archives Center, National Museum of American History
objectType: label: Type
content: Archival materials