Description
Westinghouse VT98 / R.E.L. No. 5 Radar Transmitting Vacuum Tube with Metal Carrying Case
Item Overview
This Canadian-made Westinghouse VT98 / R.E.L. No. 5 is a high-power radar transmitting vacuum tube supplied with its protective metal carrying case. The type belongs to the early generation of World War II radar valves that produced powerful radio pulses for military detection equipment.
Identification and Features
The tube carries both British and Canadian identification. Its protective metal case has internal springs that cushion the fragile tube during transport.
- V.T. 98: British military valve type
- 10E/224: Air Ministry stores reference
- Westinghouse — Made in Canada: manufacturer and country of production
- R.E.L. No. 5: Canadian designation marked on this tube
- AM and crown: British Air Ministry marking
Function
A triode uses a heated filament, control grid, and anode to control electric current. In a radar transmitter, the VT98 helped generate brief bursts of radio-frequency energy. A separate receiver detected the returning echoes, and the time between transmission and return allowed the radar to measure a target's distance.
Electrical Specifications
The VT98 used a thoriated-tungsten filament and was designed for pulse operation with forced-air cooling. The original type specification lists a filament supply of 8.25 volts at 35 amps and a maximum anode heat dissipation of 750 watts. That 750-watt figure describes the heat the anode could dissipate; radar pulse output was a separate measure.
Documented End-Item Application
The VT98 type was used in transmitters for Britain's Chain Home Low, or CHL, radar. These ground-based sets detected low-flying aircraft that could pass beneath the coverage of the main Chain Home stations. This places the valve design within the equipment developed to close an important gap in Britain's early-warning network.
Product History
The VT98 developed from the earlier VT58 transmitting valve, adopting a thoriated-tungsten filament. Wartime researcher Douglas Myhill recalled trials of the new type in spring 1940. The valve was later designated CV1098 under Britain's Common Valve numbering system. A Ministry of Supply specification dated January 18, 1950, documents that designation after the war.
Canadian Production History
Research Enterprises Limited, or REL, was a Canadian Crown corporation established in 1940 to produce radar and optical equipment for Allied forces. Canada's National Research Council supplied designs, engineering support, and staff training for this effort. This tube's Canadian Westinghouse marking, R.E.L. designation, and British military references illustrate the international supply links behind Allied radar equipment.
Parent-Equipment History
Chain Home Low grew from British Army coastal-defence radar research at Bawdsey during the late 1930s. Equipment developed to locate ships also proved useful for tracking aircraft at low altitude. Trials in 1939 demonstrated this ability, leading to the use of coastal-defence technology as a supplement to the existing Chain Home system.
Weapon-System Background
British air defence relied on radar stations, plotting rooms, communications, and fighter control working together. Radar reports helped controllers place fighters near approaching enemy formations, where pilots could make visual contact. Transmitting valves such as the VT98 supplied the radio energy at the beginning of this detection and interception process.
History of Use
Chain Home and CHL provided early warning during the Battle of Britain in 1940 and continued to warn of raids during the Blitz. Night interception required more precise control, encouraging the development of Ground Controlled Interception radar from CHL technology. The first production GCI station became operational at RAF Sopley on January 1, 1941, marking another step in the growth of radar-directed air defence.
Condition
Please check the pictures for the general condition of the item.
Ideal For
The tube and protective case offer a tangible way to explain early radar electronics and the transport of delicate military components.
- World War II radar and RAF equipment collections
- Canadian wartime manufacturing displays
- Historic vacuum tube and military radio collections
- Museum exhibits about Allied air defence
- Educational displays about early radar technology
Approx length 1.5", Approx width 10.5", Approx height 20", Approx weight lbs.
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