 Farnsworth applied for a patent for his "electron multiplier" on March 3, 1930 and demonstrated its application in 1931.Farnsworth continued to improve the device, which would come to be called a "multipactor", such that it reportedly could amplify a signal to the 60th power or better, and showed great promise in other fields of electronics.A significant problem with the multipactor, however, was that it wore out at an unsatisfactorily rapid rate.