Abstract :
The focusing and other properties exhibited by gas-focused and electron-lens-focused oscillographs when radio frequencies and ultra-high frequencies of deflection are used, are compared and contrasted. The superior focusing properties of, and absence of origin distortion in, the electron-lens-focused tube are demonstrated. Characteristics peculiar to either type of tube are discussed and some phenomena common to both types, when used a very high frequencies, are described. Finally, two applications of the cathode-ray oscillograph at very high frequencies are suggested.