Some experiments on conducting screens for a U-type spaced-aerial radio direction-finder in the frequency range 600¿1200 Mc/s

A description is given of a simple U-type rotatable radio direction-finder, which was used to investigate the improvement in performance of short-wave direction-finders obtained by the use of large earth screens, and to determine the smallest ratio of screen-size/wavelength for which the polarization errors were reduced to a satisfactorily small value (¿1 deg). The screens were constructed of sheet metal, wire netting and radial wires, and the results showed that provided a metal sheet was not less than 4¿ in diameter, polarization errors as small as 1 deg could be attained. For wire-netting screens of the same diameter, a mesh size not greater than ¿ was required to attain this performance.