hi i have read in one of the old ARRL books about a hula hoop antenna
that
only stands about 3 inches high on 10 mters but works like a full size
dipole has anyone built one and if so how did it work
many thanks
dave

Well, the first part is correct- the DDRR, but as far as working as well
as
a full length dipole- that remains in the realm of the marketing folks.

Not to mention that unless you remotely tune the capacitor it is very narrow
banded.