Mullard "ORA" type A receiving valve
date: label: date made
content: ca 1923
name: label: maker
content: Moorhead Laboratories
label: maker
content: Mullard
notes: label: Description (Brief)
content: A British triode in original box. Metal four-pin base with four brass pins and plastic insulator. "P" and "G" stamped on shell. Tipped tubular glass envelope. Stamped on one side: "Mullard / [circuit diagram with] "O", "R", "A" / O114 / Regd. Trade Mark". Stamped on other side: "Type Approved by Postal System / BBC / Protected By Patent". Box reads: "Mullard Radio Valve / "ORA" / Type A / British Made", and "Mullard "ORA" Valves are designed to Oscillate -- Rectify -- Amplify -- for use in Spark, C.W. and Telephone Receivers. Connect in the usual way and for best results apply voltages as follows: -- Filament Voltage 3.6 - 4.0 / Anode voltage 30 or higher." Also, "Important notice / Letters Patent No. 135792 / This valve is constructed in accordance with the above Letters Patent and is licensed thereunder subject to the strict condition that it is NOT TO BE RE-SOLD to the Public at a lower price than 12/6. Any breach of this condition renders both seller and buyer liable to an action for infringement of the above patent." And: "The Mullard Radio Valve Co., Ltd. / Nightingale Land, Balham / London, S.W.12. / Telephone: [??]rsco 1062 / Telegrams: "Radiovalve, Wandscom, London" / Codes: A.B.C. (6th edition), Bentley." Handwritten notes on the inner sleeve include: "Cardiff 18.42 Y / Newcastle 38-11? / Glasgow 48-126 / Manchester 38-88". Reference: Tyne, "Saga of the Vacuum Tube," page 377-378.
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.322496
label: catalog number
content: 322496
label: accession number
content: 241556
objectType: label: Object Name
content: triode
label: Object Name
content: vacuum tube
physicalDescription: label: Physical Description
content: cardboard (box material)
label: Measurements
content: tube: 4 1/8 in x 1 1/4 in; 10.4775 cm x 3.175 cm
label: Measurements
content: box: 4 3/4 in x 3 in x 2 3/4 in; 12.065 cm x 7.62 cm x 6.985 cm