Model 513

Vertical dipole log periodics offer the advantages of gain and substantial power handling capability without the requirement of a complicated ground screen for impedance matching. Unfortunately, to serve lower frequencies, large tower heights are required since the tower must be somewhat larger than a half wavelength at the lowest operating frequency. This is a penalty in severe environments and near airports.

Monopole log-periodic antennas, on the other hand, are smaller in the vertical dimension. This reduced height is a structural advantage and an operational benefit near airports. However, monopole log- periodic antennas provide less gain and require, in general, a complicated and costly process of installing a ground screen.