Different antenna systems were tested for both horizontal andvertical directivity on this wavelength at distances of from 7 to 30 miles. The antennas used in these experiments included parabolic antenna, V-type, double V-type, Adcock antennas, etc.
Using an Adcock antenna the azimuth of the incoming electromagneticwave can be defined within one half degree accuracy, and witha slight modification of the receiving elements to form a horizontal Hantenna, the vertical angle of the incoming wave can also be obtainedwith the same degree of accuracy. The former antenna can be convertedinto the latter by mechanical means within a few seconds and thus bothvertical and horizontal angles can be measured with the same antennaset-up.
With the antenna one and a half wavelengths above the ground andwith the ground surface homogeneous in the immediate vicinity of thereceiving antenna, the direction of the incoming electromagnetic wavecoincides with that of the transmitter emitting the wave, with in thesame accuracy of one half degree.
Deviations from the true directions at different locations andat different times were observed.
A simple theory of reception of the horizontal H and the Adcockantennas were also given.
The receiver used for this experiment is a superheterodyne receiverspecially designed for this purpose using a resistance-coupledI-F ampligier. It is very stable in operation and has ample sensitivity.
