Magnavox type MA5R Aeroplane-Telephone set
date: label: date made
content: 1918
name: label: maker
content: Magnavox Company
notes: label: Description (Brief)
content: Magnavox type MA5R Aeroplane-Telephone intercom / radio set in original box, with inspection tag dated November 1918. Box stamped: "S. C. [Signal Corps] Order No. 140275 / Radio Req. No. 178". Unit consists of a power switch, a master plug box, four remote plug boxes, three splitters, and one pushbutton, all connected by a varnished(?) cloth-insulated wiring harness. Harness polarity is indicated by one cable having a spiral wire wrapped under the insulation while the other cable is smooth and flat. The cables run parallel with all components attached to the spiral cable. An extra length of heavy insulation covers both cables about 36" past the master plug box.
label: Description (Brief)
content: Wiring circuit as follows: flat cable with two bare wire ends travels 88" to the switch box. A 9" flat cable connects the switch box to the master plug box. A 7" spiral cable connects the master plug box to the first splitter where the circuit branches. One branch is a 72" spiral cable leading to remote plug box #1. The other branch is a spiral cable leading to the second splitter where the circuit branches again. One branch is a 44" spiral cable leading to remote plug box #2. The other branch is a spiral cable leading to the third splitter where the circuit branches again. One branch is a 32" spiral cable leading to remote plug box #3. The other branch is an 8" spiral cable leading to remote plug box #4. The return leg of the circuit begins here with a 14" flat cable connecting plug box #4 to a push button, and an approximately 264" flat cable connecting the pushbutton back to the master plug box.
label: Description (Brief)
content: Markings and component details as follows:
label: Description (Brief)
content: A) power switch box: "On" "Off", 2-lead power cord, no end connectors.
label: Description (Brief)
content: B) master plug box: serial #872, switch labeled "Radio" and "Inter", 2 ports are on this plug box, two 2-prong plugs are also connected to this box, each on a 24" cord with the ends reinforced with tar tape.
label: Description (Brief)
content: C) four remote plug boxes: no markings, each box has two ports.
label: Description (Brief)
content: D) three round splitter cans: no markings.
label: Description (Brief)
content: E) pushbutton: round case, plastic button, "Magnavox" molded on case.
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.241556.085
label: accession number
content: 241556
label: catalog number
content: 241556.085
objectType: label: Object Name
content: telephone set
physicalDescription: label: Measurements
content: power switch: 2 3/4 in x 5 1/2 in x 4 in; 6.985 cm x 13.97 cm x 10.16 cm
label: Measurements
content: master plug box: 5 1/2 in x 7 1/4 in x 4 1/4 in; 13.97 cm x 18.415 cm x 10.795 cm
label: Measurements
content: remote plug boxes: 2 1/4 in x 5 5/8 in x 3 in; 5.715 cm x 14.2875 cm x 7.62 cm
label: Measurements
content: splitters: 3/4 in x 2 1/4 in; 1.905 cm x 5.715 cm
label: Measurements
content: pushbutton: 1 1/2 in x 3 in x 2 in; 3.81 cm x 7.62 cm x 5.08 cm
label: Measurements
content: box: 7 3/8 in x 20 5/8 in x 8 1/8 in; 18.7325 cm x 52.3875 cm x 20.6375 cm