the words counterpoise and ground plane are used interchangeably in common usage. they mean the same thing. deal with it. all you're doing by insisting that they're somehow different is adding to the confusion.
http://www.atis.org/tg2k/_counterpoise.html
Both terms are equivalent but you will find below their accurate definition by ARRL.
*Ground plane : A system of conductors placed beneath an elevated antenna to serve as an earth ground. Also see counterpoise.
*Counterpoise : A wire or group of wires mounted close to the ground, but insulated from ground, to form a low-impedance, high capacitance path to ground. Used at MF and HF to provide an RF ground for an antenna. Also see ground plane.
*so if there is ANY difference between the two it would be that a ground plane is elevated above the ground while a counterpoise is used close to the ground. they both accomplish the same thing. the word counterpoise means "balance" and it just so happens that this is one of the functions of a counterpoise or ground plane, to provide a balance, in this case a balance in the antenna currents between the antenna and either earth ground or any substitute or artificial ground.
here's another example of just how interchangeable they are. this is worded almost the exact opposite of the paragraph above.
*In fact both definitions are correct. But most of the time, we speak of radials when the wires are laid evenly on the ground, and of counterpoise when the antenna is erected a few meters above the ground and surrounded by an artificial ground plane made of thin tubing. Of course it will be never false to say that a ground plane antenna is surrounded with a system of radials.
that's confusing enough as it is already. read all four references marked with *. they contradict each other yet they are all found in the same page. that's as interchangeable as you can get.
"when was the last time you saw one with two elements or less, other than when one was broken?"
when building an elevated quarter wave vertical for fixed operation using ONE round piece of sheet metal with a 1/4 wave length radius for the 'groundplane' 'counterpoise' for 2 meter operation. then i made a radial cut in the sheet metal and gradually overlapped the two edges and used the conical shape of the surface to obtain a 50 ohm match to the feedline. ("radial droop effect") when the appropriate amount of overlap and the attendant "cone shape" were achieved, i simply cut off the excess and soldered the seam together in place. i don't recommend this procedure for 27 mhz.
so a counterpoise and a groundplane ARE the same thing and they perform the same function, with the only distinction between the two being the particular application, either ground mounted or elevated, and even then the terms are still used interchangeably. in any event, any difference between the two of them has ABSOLUTELY NOTHING to do with the number of conductors.
now all 3 of you can go gang up on someone else. i know what i'm talking about.
Coily
