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Short cylindrical antennas have been loaded to resonate at frequencies lower than their natural frequencies by means of dielectric sheaths of cylindrical and conical form. These loadings are compared experimentally with loading by means of metal disks at the ends of the antennas. Resistances at resonance calculated by the Poynting vector method for two assumed current distributions are compared with the experimental results. It is shown that for a given current distribution at resonance, the antenna radiation resistance depends only on the antenna length in wave-lengths. Particular loading methods alter the current distributions. Those which produce more nearly uniform current distributions yield higher radiation resistances.

In this paper a brief theory is given about the amplitude and probability density distribution of a narrow band shot noise. It is found that the probability density distribution follows the normal law and the amplitude distribution is the integral of the normal function. However, if the noise voltage is applied across a nonlinear impedance such as a type 1N34 crystal diode, both the amplitude and probability density distributions are changed. The change depends upon the current-voltage characteristic of the nonlinear impedance. An experimental method is described which can be used to measure the amplitude and the probability density distribution. The noise source was a photomultiplier tube followed by a narrow band amplifier centered at 16 kc. The measured results agree with that obtained by calculations.