Frnak McKenney wrote:
. . .
Okay... ARRL Antennas, Chapter 8: Multielement Arrays. We've got
an (approximately, given skip) vertically-polarized 10MHz signal, so
the E-field is moving up and down and the wavefront is a circular
ripple (nearly a straight line by the time it gets to Richmond)
travelling roughly west-to-east, that is, it's hitting my house
end-on.
. . .

I definitely think I'm missing something, but then, I haven't really
made it that far into the Antenna Handbook.

While you're looking at the ARRL Antenna Book, look over the chapter on
propagation. You'll find that when receiving a signal by ionospheric
skip (as you are), the polarization will be randomly oriented. So
there's no point in choosing your antenna orientation on the basis of
some supposed wave polarization. Its orientation will, however, have a
striking impact on its pattern, so you should choose the orientation to
get the most favorable pattern.

The fading in and out of the WWV signal you described in an earlier
posting is very likely due largely or at least partially to polarization
shift -- the signal fades when the polarization rotates to be crosswise
to your antenna, and gets loud when the polarization lines up with your
antenna's. I've seen tens of dB difference switching between a
vertically and horizontally polarized antenna, with the change going the
other way after a minute or so when the polarization rotates. If your
receiver needs a constantly strong signal, you're going to have a hard
time getting it what it needs.

I haven't followed the thread closely, so please pardon me if I've
missed something. Your initial description of the problem sounded like
receiver overload. A sharp preselector would help a lot, although it
sounded like you were using a tuned loop which, if carefully balanced,
should provide that function. If a preselector isn't enough, the next
step is to add an attenuator -- I have to use one between my TV and its
antenna, in fact. You should consider the possibility that the 10 MHz
WWV signal itself is overloading the receiver, in which case an
attenuator is necessary, and the last thing you'd want to do is use a
better antenna. A directional antenna can be used to reduce the strength
of interfering signals if they're coming from directions different than
WWV. But making an antenna which has good rejection in the right
directions can be something of a project.

Roy Lewallen, W7EL