Fig. 20 D165529 Sound Spectrograph Recorder Unit, Charcoal Filter Removed. Bell Telephone Laboratories, Inc.
name: label: Collection Creator
content: Kopp, Harriet Green, 1917-
setName: label: See more items in
content: Harriet Green Kopp Papers
label: See more items in
content: Harriet Green Kopp Papers / Series 3: Photographs (#1-215)
unitdate: label: Date
content: undated
container: label: Container
content: Box 2, Folder 6
dataSource: label: Archival Repository
content: Archives Center, National Museum of American History
identifier: label: Identifier
content: NMAH.AC.1130, File KOPP_188
objectType: label: Type
content: Archival materials
label: Type
content: Graphic Materials
originalsloc: label: Original Negative Number
content: 118407