How does antenna height affect the azimuthal radiation pattern of a horizontal dipole HF antenna at elevation angles higher than about 45 degrees?
AnswerIf the antenna is less than 1/2 wavelength high, the azimuthal pattern is almost omnidirectional
When a horizontal dipole is lower than about one-half wavelength, ground interaction fills in the azimuth pattern at high elevation angles, making it nearly omnidirectional.