"James" wrote

How long should it be?
Does it need to be vertical, horizontal or somewhere in between? Which is
best?
What about guage of the wire? Radio Shack has a 70 foot stranded copper
wire
14 guage with a couple of insulators as some sort of kit.

That's a good good starting point James.

Could something like this be strung on steel insulated fence posts that
are
normally used for keeping livestock from wandering? That would put it
close
to the ground. I know that higher is always better.

It is indeed, but one of the radio shack "kits" I had 40' up in a tree came
down in a hurricane, and annoyingly (to me) worked almost as well lying on
the ground. Because of it's length, it still worked in it's desired bands
better than an elaborate fan-antenna of two long wires and transformer that
did survive the hurricane. A long wire parallel to the ground will have
directional aspects to it's reception. The steeper of an angle (but avoid
more than about 60 degrees) the less directional it will be.

I have lotsa room on the place here.

That also implies "quiet" from urban noise, and great for shortwave
listening.

You would probably enjoy any of the used Radio Shack DX-series shortwave
radios normally available on eBay. A lot less money and some are more
capable than anything Grundig made. Of course the Grundigs will pick up
nearly anything with the stock whip. But Grundig like many of it's kind were
not made for real external antennas - and doing so does often just overloads
the input to the detriment of all listening. The old Radio Shack DX series
are made for long external antenna usage, as are all table-top/base type
communications receivers.

Good listening.

Jack