"J.B. Wood" wrote...
the argument that the slant wire to the tower adversely modifies the
antenna pattern doesn't seem to hold up in theory or practice.

Linked below is a clip from "Radio Antenna Engineering" by Edmund Laport,
which does show some pattern effects from shunt feeding a monopole. The FCC
dislikes shunt fed radiators for AM broadcast stations (especially for
directional arrays), as their skywave radiation patterns are inconsistent,
and interference ratios are more difficult to predict.

http://i62.photobucket.com/albums/h8...d_Patterns.gif

R. Fry