"AndyS" wrote in message
oups.com...
The radiating element, which you are measuring, has to have a
counterpoise (ground) to establish the Efield against and an Hfield
around.

I believe that -- at least from a mathematical perspective -- "infinity" is a
perfectly good counterpoise. (Just as isolated conductors have capacitance to
infinity and inductors have "partial inductance" whereby a return path at
infinity is assumed.)

As a practical matter, of course the user's hands and other objects in the
environment will affect the measurement, but suggesting that "one must always
have a well-defined counterpoise" would tend to discourage one from studying
antennas that are less sensitive to counterpoises than those that are, and
this endeavor is quite valuable for the design of miniature antennas. After
all, there are millions of commercial devices in operation every day for which
the counterpoise is ill-defined.