early cathode-ray tube
Date: circa 1920
Inventory Number: 2008-1-0081
Classification: Cathode Ray Tube
Subject:
Maker: Western Electric Company (1881 - 1995)
Cultural Region:
Place of Origin:
Dimensions:
33 x 12 cm (13 x 4 3/4 in.)
Description:
A Cathode-ray tube with a bulb shaped like an inverted flask. Its glass is frosted on the inside at the "base" of the flask. It has a four-prong metal socket, with a small nipple on the side of the socket. The neck of the bulb contains a thin inner glass tube with filaments inside, and a metal nozzle pointing toward the frosted face. Surrounding the beam path are two sets of parallel rectangular metal plates, connected electrically to the socket and set at right angles to each other.
Signedstenciled on wider part of bulb: WESTERN ELECTRIC / MADE IN U.S.A.
Inscribedstenciled on narrow neck of bulb: TYPE C / 176674
engraved on metal base: PAT IN U.S.A. / 2-18-08 12-23-16 / 10-5-20 / PATS APPLIED FOR
small round sticker with old series number: #A010
engraved on metal base: PAT IN U.S.A. / 2-18-08 12-23-16 / 10-5-20 / PATS APPLIED FOR
small round sticker with old series number: #A010
FunctionThis is a cathode ray tube that has all its components visible, as it is made of clear glass. Tubes like this one shoot a stream of electrons (cathode rays) from a nozzle at the base, which are accelerated towards a screen at the wide end of the tube, after passing through two series of deflector plates perpendicular to each other. Each set of deflector plates is made of parallel plates that can be electrically charged by a voltage, creating an electric field that deflects the electrons. If one connects the deflector plates to an electric signal, it can be visualized on the screen.
Cathode ray tubes like this ones are the basis for oscilloscopes and television.
Cathode ray tubes like this ones are the basis for oscilloscopes and television.