David Forsyth wrote:

In the interest of my recent tinkerings with radios (both antique and
homebrew), I have put up an 80 foot straight wire antenna above the house.
It sits about 35 feet up from, and horizontal to, the ground. I am using a
lead in from one end made of insulated stranded copper wire (basically old
speaker cable, about 18 guage I think). Right now, the lead-in wire comes
down from the end of the antenna closest to the sun porch, and in through
the storm window via a well-insulated bushing. Due to the location of this
lead-in, this is the spot wherre I have been doing most of the tinkering
with the radios. I also have a copper pipe ground rod in a nearby location
so as to have as short a path to ground as possible.) It seems to work OK
for now but I would ideally like to run the lead-in into my basement where
my workshop is. I read somewhere (I think it might have been in reference
to crystal sets) that you can use coax for an AM lead-in. Would this be
better for a longer/more convoluted lead-in? Would I use the braded shield
as the ground connection or would I run a separate ground back to my copper
rod outside? What type of coax would be best for this sort of thing? I am
interested in receiving both broadcast and shortwave. Any info on this
matter would be most appreciated.

thanks in advance,

Dave

Forget using coax or a preamp with that antenna. With an 80'
wire antenna for AM and shortwave reception, there is nothing
to be gained by their use, and you can degrade what you already
have. Just add a static discharge unit, connect the wire to the
receiver, and enjoy your antenna.

If you want to make improvements, you can modify the antenna,
and/or make an antenna tuner for it or use a different antenna.
But as it stands today, it should give you plenty of signal
for the use you have in mind. Running the wire into the
basement is not a problem - just make sure you don't damage
it, and route it away from metal objects.