US 1941424 A
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Description (OCR text may contain errors)
Dec. 26, 1933. J. WELLS 7 1,941,424
INTERFERENCE ELIMINATOR Filed April 22, 1951 A [mentor far/le s G. WeZLS 5 M.
Patented Dec. 26, 1933 UNITED STATES 1,941,424 7 INTERFERENCE ELIMINATOR James G. Wells, Chicago, Ill., assignor to G-M Laboratories, Inc., Chicago, Ill., a corporation of Illinois Application April 22, 1931. Serial No. 531,951
My invention relates to a device for suppressing radio radiations from .an oscillating apparatus and more particularly for suppressing or ab sorbing disturbances emanating from a neon sign.
Neon signs are frequently used in establishments where radio receiving sets are displayed for sale and it has been found that. in many cases the operation of the sign interferes seriously with the operation of radio sets in the vicinity of the sign.
An object of the invention is to provide a method and device for suppressing radio emanations from a device which generates radiant energy.
A further object is to provide a device for suppressing radio emanations of a neon sign.
Other objects and advantages will appear as the description proceeds.
The single figure of the drawing illustrates schematically an embodiment of the invention. The drawing illustrates a gaseous discharge tube such as a neon tube formed into the letters "G-M. This tube is energized by means of a constant current transformer 4, the terminals of the secondary winding of which are connected to electrodes 5 in the ends of the tube.
When such tubeis used in a sign, there is set up an oscillation, the frequency of which is determined by the length and configuration of the glass tubingforming the casing for the gas. This frequency is also effected by the capacity of the tube to ground and the degree of ionization of the gas in the tube. The tube therefore radiates a damped wave modulated by the supply source frequency that will set up a disturbing interference to nearby radio systems.
It has been found that the radiant energy emanating from the tube may be suppressed by placing an elongated or looped conductor in the vicinity of the tube. When the impedance of the loop is equal to the impedance of the circuit setting up the oscillations, the absorption of the energy radiated from the tube will be a maximum. By designing this loop to lengths suitable for the particular length and configuration of the tube and attaching the ends of the conductor to the tube, it has been found that the objectionable radiation from the tube may be suppressed.
In practicing the invention I take a conductor 6, having clips '7 attached to its ends and secure one end of the conductor approximately a foot from one end of the tube. The position of the other end of the conductor is then determined by the experiment, attaching it to various points of thetube adjacent the opposite end of the tube until the point is found at which the interference is no longer noticeable. If the position of the two ends of the conductor held by-the clips does not result in the elimination of the disturbance, I change the length of wire and repeat the experisuppress radiations therefrom.
It will be understood that the nature and embodiment of the invention herein described and illustrated is merely a convenient and useful form of the invention and many changes and modifications may be made therein without departing from the spirit and scope of the invention.
What I claim as new and desire to protect by Letters Patent of the United States is:-
1. In combination with a gaseous discharge tube'a long conductor attached to said tube at two points. to suppress radiant energy emanating from the tube.
2. A method of suppressing radiant energy emanating from a gaseous discharge tube which consists of connecting a conductor adjacent one end of the said tube and connecting the other end of said conductor to a point adjacent the other end of said tube at which radiant energy generated by said tube is suppressed.
3. In combination with a gaseous discharge tube comprising an insulating gas filled tube having a pair of electrodes, a metal clamp secured tothe insulating tube near one electrode, a secand metal clamp secured to the tube, and current conducting means connecting the two clamps, said second metal clamp positioned to cause said current conduct-ing means to suppress high frequency radiation from the tube.
4. In combination with a space discharge tube having an insulating body, and a pair of electrodes, a looped metal conductor having a pair of terminals, and means for securing said terminals to the insulating body, said terminals being spaced from said electrodes.
5. In combination with a space discharge tube comprising a relatively long insulating tube body having a pair of electrodes at opposite ends thereof, a pair of clamps each secured around the tube, and a looped conductor having its ends connected to the clamps.
' 1 JAMES G. WELLS.