On Aug 2, 12:30�pm, "KJ4NTS" wrote:
I'm confused about the requirements for a counterpoise for an end-fed wire antenna. �I understand
that it's needed, but I don't understand what the requirements are.

Can a ground stake at the base of the feed point serve as a counterpoise, or does it need to be
another wire running under the ground below the antenna?

If a wire is required, how long does the counterpoise have to be?

Would it be better to use insulated or uninsulated wire for a buried counterpoise?

An end fed wire antenna should be very close to a half wave in length
for the intended frequency. If coax fed, the objective is to make the
antenna look as balanced as possible by insuring that the current in
the counterpoise and the radiating element are very nearly equal. A
half wave end fed is a high voltage low current antenna, and
everything around the antenna will affect its impedance and balance,
obviously the counterpoise will have a large effect.

If the end fed antenna (half wave) is not in the clear, then the
counterpoise is cut-and-try. If in the clear, antenna modelling will
provide useful results, see W8JI web pages. A counterpoise is needed,
but without knowing your exact situation, cut-and-try is your best
bet.

Gary N4AST