Interaction between antennas

From Contesting

Contesters have recently begun paying more attention to interaction between antennas, and between antennas and towers. This section will deal in detail with the diagnosis and treatment of such problems, which can disastrously affect the performance of otherwise excellent antenna systems.

Interaction between towers and verticals

This modeling study by N6LF examines a simplified case of coupling between a vertical and a nearby tower, and demonstrates that even non-resonant towers can affect the feedpoint impedance and pattern of a vertical at spacings of 1 wavelength or more.

Moving from the theoretical to a practical case in point, N6LF and W2JVN went to NK7U's contest station to assess interactions between towers and a new 80-meter 4-square array.

More measurements and modeling of NK7U's problem identify the principal culprit.