Summary

Type 2Q15 oscillation valve. filament. volts 15, amps. 9. plate volts 1500. Made by De Forest Radio Telegraph & Telephone Company, New York, United States of America. This type of tube was first used in Australia by the Post-Master Generals Dept in 1921, according to the donor, but Marconi valves took their place later.

Oscillion was the term DeForest used for transmitting valves designed to be used as oscillators. No data for this particular valve has been found but it looks the same as the type 1G Oscillion, which was rated at 500 watts input power (as llustrated on page 130 of 'Tyne, Gerald F. 1987. Saga of the Vacuum Tube')'.

Physical Description

Cylindrical bulb with nickel plated end caps, mounted on wooden block with display label. Base has a flat pin and two square pins.

Significance

This valve is a very early example of a De Forest transmitting tube. De Forest invented the triode in 1905 but did not make high vacuum tubes untilthe First World War period, 1914 to 1918.

More Information

  • Collection Names

    Electronic Valve Collection

  • Collecting Areas

    Information & Communication, Engineering

  • Acquisition Information

    Donation from Amalgamated Wireless (Australasia) Ltd, 29 Apr 1926

  • Manufacturer

    De Forest Radio Telegraph & Telephone Co, New York, New York State, United States of America, circa 1921

  • Inscriptions

    Text on display label. Bulb: (signature of Lee De Forest)/PAT. OCT.17 1916 /639 (the last digit is indistinct) Top cap: De Forest Oscillon/(Licence statement)/(Tube data) Label riveted to top cap (see note below): DE FOREST OSCILLION/PAT. NOV. 7. 1905/LICENSED ONLY FOR THE USES/SPECIFIED IN CONTRACT OF SALE/TYPE 2Q15/FIL.VOLTS 15 FIL.AMPS 9/PLATE " 1500 PLATE " 1111(?)/DE FOREST RADIO TEL. & TEL. CO.. N.Y. Note: All of the numbers on the top cap label, apart from the patent date, are stamped into the label. In particular note that the 'Q' of the type number is printed on the label but both the '2' and the '15' have been stamped on.

  • Classification

    Electronics, Vacuum technology, Amplification

  • Category

    History & Technology

  • Discipline

    Technology

  • Type of item

    Object

  • Overall Dimensions

    355 mm (Height), 91 mm (Outside Diameter)
    Dimensions of valve, excluding display block.

  • References

    Tyne, Gerald F.J.: Saga of the Vacuum Tube, Howard W Sams Inc. 1987. P 130
    [Book] Tyne, Gerald F. 1987. Saga of the Vacuum Tube., 1987, 130 Pages

  • Keywords

    Thermionic Electron Valves