Bell Labs type 175HQ deep-sea telephone repeater tube
date: label: date made
content: ca 1957
name: label: maker
content: Bell Telephone Laboratories. Murray Hill Laboratory
notes: label: Description (Brief)
content: Double ended cylindrical envelope with ceramic bases at each end. "[?] for ch [?]" printed on envelope. Donor’s card reads: “Cable repeater tube (pentode) made by the Bell Telephone Laboratories for use in the trans-Atlantic telephone cable placed in operation by AT&T on the morning of 25 September 1956. There were a total of 306 of these tubes submerged with the cable.
label: Description (Brief)
content: At 11:00 am on that date Chairman Craig of AT&T said “This is Mr. Craig calling Dr. Hill in London.” At Lancaster House in London, Her Majesty’s Postmaster General replied, “This is Dr. Hill, Mr. Craig, I am delighted to hear your voice.” So began the first conversation over the trans-ocean telephone cable.
label: Description (Brief)
content: Filament: heater type, 18.2 volts at 220 milliamperes; 1.3 volt negative bias on the control grid; screen voltage 32; plate voltage 38 at 1.3 milliamperes; transconductance 980 microohms. The most durable tube made up to this time for general commercial use. These tubes are lighted for 5000 ours before any test are run. The life expectancy is over 200,000 hours, or over 20 years.”
label: Location
content: Currently not on view
setName: label: See more items in
content: Work and Industry: Electricity
creditLine: label: Credit Line
content: from Paul G. Watson
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: EM.324434
label: accession number
content: 252994
label: catalog number
content: 324434
objectType: label: Object Name
content: Vacuum tube
label: Object Name
content: telephone amplifier tube
label: Object Name
content: pentode
physicalDescription: label: Measurements
content: overall: 3 3/4 in x 1 1/4 in; 9.525 cm x 3.175 cm