Bill Turner wrote:

They're great if you like your antenna two feet above ground.

The way you "null out the voltage" is by making that wire resonant and
resonant wires love to radiate. Nobody would intentionally install an
antenna below knee level, but that's what you're doing.
. . .

I don't agree entirely with some of the recent short postings. And
making a wire resonant doesn't make it radiate any better or worse than
a non-resonant one. But if you have an unbalanced feedline (and by this
I don't mean a symmetrical feedline like ladder line, but one of any
construction with imbalanced currents) and consequential current from
your rig to ground, that conductive path to ground will radiate just
like an antenna -- any current flowing on a conductor causes radiation,
regardless of whether we consider it to be an "antenna", a "ground
wire", or a "transmission line". And as Bill points out, the location of
a ground wire isn't usually what you'd choose for an antenna. Other
consequential effects are that an unbalanced feedline has a net (common
mode) current and so it radiates, too. The feedline and ground wire are
also part of the antenna when receiving, so they'll be good at receiving
noise that's generated in the house or radiating from mains wiring. All
in all, it's not an ideal situation, although quite a number of people
manage to get away with it.

Roy Lewallen, W7EL