On Tue, 19 Jun 2007 09:16:30 -0400, Chuck
wrote:

BTW, I was assuming a half-wave,
horizontal antenna, one end of which is
brought directly into the shack with no
intervening transmission line.
Definitely not a dipole, but not a
monopole either, I suspect.

Hi Chuck,

It is merely an off-center dipole that hasn't come out of the closet.
The wiring in your shack supplies that other half, and supports the
common mode current/voltage.

There are
some reports out there of RF in the
shack with this arrangement, but
who has experienced matching problems?

The complaints made here are far from sparse. On the other hand,
those who don't notice, don't complain. I will bet you have one
outlet in your home with inverted neutral/hot and a floating ground.
Does it bother how your lamp works? Plug in a toaster and reach for
the faucet and the morgue attendant will tie a nice card to your toe.

Some folks have common mode complaints, others don't.

So if there were no common mode issues,
the directly end-fed, half-wave wire
would be an equal opportunity candidate
along with the traditional dipole for
the same radiator geometry? Or is that
like saying if it weren't for gravity I
could fly?

For wires less than 5/8ths (end-to-end), you have to work (or screw
up) damned hard to gain or lose half a dB from the typical lobe
geometry. I will be generous and call it a whole dB, but that is
barely the width of your S-meter's needle. There are other things to
worry about in life, like that outlet with a floating ground. In that
vein, you stand to come out ahead if you seriously examine your
shack's quality of ground for all applications.

73's
Richard Clark, KB7QHC