Some Characteristics of Ultra-High-Frequency Transmission

A receiving equipment and calibration method is described for the measurement in absolute units of 5.1-meter (58.8-megacycle) field strengths. A transmitter of low power is used. The attenuation of the waves is discussed, and a field strength contour map of Ann Arbor, Michigan, and vicinity is presented. The attenuation constant is found to be 0.36. Experiments on receiving antenna lengths show the importance of a properly resonant receiving antenna. The field distribution around the transmitting antenna is investigated by rotations of the antenna with the receiver at a fixed location. The polarization of the waves is studied, and results indicate that horizontally polarized radiation is more rapidly attenuated than is the vertically polarized.