Feasibility of the Low Antenna in Radio Telegraphy

This paper supplements a previous publication entitled "High versus Low Antennas in Radio. Telegraphy," in which it is shown that if the antenna of a radio telegraph station consists of an extended horizontal network of wires mounted above a highly conducting plane, and if the mean radius of the capacity area is two or more times as great as any height above the plane at which it is feasible to mount the network, then the rate of radiation from the antenna at a given voltage and frequency, and the rate at which the antenna will ultimately be able to abstract energy from impinging (sustained) waves, are both independent of the mounting height. The conclusions in the previous paper are the result of a mathematical analysis for the hypothetical case in which the antenna is mounted over a highly conducting plane. The present paper deals mainly with those wasteful antenna and earth resistances which are common to the use of the low antenna both in sending and receiving. The distinction between the "low" antenna and the "ground" antenna is pointed out. The electrical constants of an antenna having the same radiation figure of merit as the Darien (Canal Zone) antenna, but mounted at an elevation of only 10 meters (33 feet), are contrasted with those of the Darien antenna. The wasteful resistances of this 10-meter Darien-equivalent are then computed. Of these losses, that in the vegetation growing under the antenna is found to be the most serious.