Editorial Consultant: Rod Burman

TETRODE VALVES USED IN SHELL FUZING WW2, 1940's

Developed possibly by Western Electric or STC at Harlow for use in Proximity Shell Fuses (See Item A0478 and A0430). It is not known if they were ever used for this purpose, as many manufacturers were asked by the British Government during WW2 to come up with a solution to the problem, of shells that would explode in the proximity to Aircraft, the biggest problem being finding a valve that could be fired from a gun and survive, (pre guided missiles) The Example of a British proximity fuse that we have (possibly one of the only surviving examples) does not use this valve. This type may well have been used in the later American version (Item A0430) which used the new Technology, 'Radar' a Phrase coined by the US, (RAdio Direction And Ranging)

A1425

RAF TYPE 'C' MOV VALVE, 1918

Valve made by the Marconi Osram Valve Co for the British Air Force around September 1918.
It is a High Vacuum Triode with a Tungstan filament, 3volt 0.75 Amps with an amplification factor of around six.

Nortel Collection

• Box for the Valve
  

A1305

BTH T5-230 VALVE, 1920's

This valve is post 1920 owing to evidence of Gettering (the blackening inside) only used after 1920.
Clearly marked BTH T5-230 a Naval Transmitting type first produced in 1919, with a candelabra cap but instead of two wires at the other end, it is fitted with a later three connection base normally used with RAF valves.
Also the candelabra cap has only one connection, for the filament the other filament wire is brought out to the tip on the other end, with anode and grid on the sides.

Nortel Collection

A1301

WW1 AEG TYPE "A" VALVE

made by AEG and used during the First world War by the Germans, and was used as a Telephone repeater amplifier
AEG the Company translated means General Electricity Company AEG was founded in 1883 by Emil Rathenau who had bought some patents from American inventor Thomas Edison.

A0787

EA50 VALVE, 1930's

EA50 Diode pre WWII, used in early television as a detector, and general signal rectification.

A0619

MOV DET25 VT25 CV1025 EDISWAN VALVE, 1932

This valve has an Anode of solid Graphite. Marconi Osram Valve Co DET25,
Made by Ediswan

A0661

WWII VT17 VALVE

VT17 Tetrode Transmitting Valve

A0927

446B-SC278A RCA LIGHTHOUSE VALVE, 1942

RCA 446-B microwave Triode used by the US Navy and known as a Lighthouse valve.

A0668

CV52 UHF TRIODE VALVE, 1942

Used as a Local Oscillator in the R1294 Microwave Search Receiver, up to 1GHz is possible and even higher using harmonics

Wartime UHF Triode of 1942.

A0665

WWII 4671 ACORN VALVE

Acorn 955 Triode 1934 followed by 954 and 956 Pentode

The Valve known as an Acorn, was one of the fist truly miniature valves and was used in Military equipment during WW2. In the 1930's RCA produced the Acorn valves consisting of a 955 Triode in 1934 followed by the 954 Pentode in 1935 and.variable-mu pentode 956, in 1936.
With an upper working frequency of 400Mhz these valves were mass produced in the USA during the Second World War for a lot of electronic equipment and a large number were imported into the UK.
These valves were not used in Proximity shell fuses, simply not robust enough.

A0620

MULLARD EF50 VALVE, 1939

EF50 Originally developed by Philips in 1939.
Used in Radar receivers and other equipment.

Mullard Pentode valve of 1939, used in many military Transceivers.

A0613

WWII TELEFUKEN P700

Valve produced during the Nazi period in Germany 1933 to 1945, and used in many Transmitters and Receivers of that period.

A0612

GT1C GEC COLOSSUS VALVE, 1939

Used in the Colossus computer at Bletchley Park. During the rebuild of the first electronic computer in the world, engineers involved in the project were serching world wide for all the valves of this type they could find as the machine used several hundred.
It is an Argon filled electronic switch. This thyratron found many uses as a timebase for radars, and in particular many were used in the Colossus computer which was used a Bletchley Park to crack the codes of the German Lorenz cipher machines.

A0599

WWII MOV PT15/ VT104 10E/215

The RAF used this valve in the 1154 transmitters placed in WW2 Bombers
See Item A0164.
It is a 25Watt RF Pentode.

A0591

TRIGATRON CV85 SPARK GAP 24B9, 1959

Enclosed spark gap.Three electrodes two for switching a high power high voltage and the third for triggering the device into conduction.
If the trigger is connected to a transformer producing a high voltage pulse, the gap between the two electrodes becomes Ionized, this forms a conducting area between the two electrodes and the device switches on, passing large currents and high voltages.
Used in pulsed Radar circuits. Specification:- 150KWatt 7.4 Kvolt 80 Ohms on resistance Frequency 2.5 Khz. Protected by a gauze sock, to contain the glass should the device shatter.

A0208

NU22C SILICA VALVE, 1937

The Navy used these valves, The envelope is made of Silica Glass. The advantage being that the envelope could be opened, the unit repaired and easily resealed and evacuated of air. More importantly Silica glass can pass higher proportions of Infra red and has a higher melting point, so the anode of the valve can run at higher temperatures. This is a half wave rectifier of 1937.

A0642