A Horizontal Loop for 80-Meter DX

In 1997 the author published an article on vertical full (and ground plane type half) wave loops for 80 meter DX. In that article it was noted that perpendicular (horizontal) polarization is the preferred polarization, particularly at low elevation angles, since horizontally polarized waves are hardly affected by the finite conductivity of the ground in front of the antenna. An exception when vertical antennas come into their own is a vertically polarized antenna over very good ground, near the seashore or over alkaline salt flats. A practical 80 meter horizontal dipole is, however, not an ideal antenna for DX. For optimum communications with distant stations the antenna’s radiation pattern should have a null overhead, to minimize near vertical incidence sky-wave signals from atmospheric noise and interference, and a low angle lobe to maximize reception/transmission over paths to distant stations. To achieve such a pattern with a half-wave dipole it would be necessary to install the dipole a half wavelength above the ground, that is to say, at a height of 40 meters for the 80 meter band. This is impractical in many instances. A full-wave horizontal loop for the 80 meter band at a practical height of 15 meters is a popular antenna nicknamed a “Loop Skywire” that has been in The ARRL Antenna Book for years. In the author’s view this antenna does not have the desired radiation pattern for 80 meter DX. Aside from the fact that the direct and ground-reflected waves reinforce at an elevation angle of 90°, the loop itself has some directivity in this broadside direction. Doug DeMaw has referred to such an antenna as a “cloud warmer.” A Horizontal Loop for 80-Meter DX