From IEEE-145-1993-R2004…
- 2.86 counterpoise. A system of conductors, elevated above and insulated from the ground, forming a lower system of conductors of an antenna.
- NOTE—The purpose of a counterpoise is to provide a relatively high capacitance and thus a relatively low impedance path to earth. The counterpoise is sometimes used in medium- and low-frequency applications where it would be more difficult to provide an effective ground connection.
Danger, Danger, Danger!!!
I use the term counterpoise in ways differing from the above definition around this site, but there is much variation in its use. Owen Duffy suggests avoiding the term and I cannot disagree. Generally speaking I should just say “extraneous conductor(s)” or some such equivalent not part of the primary portion of the antenna. What this is can vary depending on mast, ground wire, transmission line length, etc.
