ABSTRACTS OF TECHNICAL ARTICLES 205 



potential tubes. Magnetic control is shown to be inferior to electric control 

 from the point of view of band-width and gain. 



Antenna Theory and Experiment J' S. A. Schelkunoit. This paper 

 presents: (1) a comparison between several approximate theoretical formulas 

 for the input im.pedance of cyhndrical antennas in the light of available 

 experimental evidence; and (2) a discussion of the local capacitance in the 

 vicinity of the input terminals, mathematical difficulties created by its 

 presence, and m.ethods of overcoming these difficulties. No exact solution 

 of the antenna problem is available at present and so far it is impossible 

 to set definite limits for errors which may be involved in various approxi- 

 mations. For this reason in appraising these approximations one is forced 

 to rely on one's judgment and on experimental evidence. It is hoped that 

 this paper will aid in correlating theory and experiment to the advantage 

 of both. 



^ Jour. Applied Physics, January 1944. 



