[R-390] SWL antenna

[Dan Merz]

Hi,  I'm moving in about 6 mo to new house being built and am considering
how to install a simple antenna for am broadcast band and HF receiving (no
transmitting).  Currently I've got a 50 ft longwire outside at about 20 ft
height  with some Radio Shack twin lead,  the cheap stuff,  coming down to a
hole in the basment wall.  It's been good enough.  In the new house I'm
thinking of a couple of options,  about a 40 to 50 feet of wire about 3 or 4
feet off the roof using a couple of pvc pipes for support and serving as the
insulators with the transmission line connected on one end.  I may be able
to put it higher but that depends on how strictly one of the covenants is
enforced.  I've gotten the ok for what I'm describing.  But I've been
wondering about the transmission line across and inside the attic house
about 40 feet across and down about 16 feet into the basement.  My first
idea was to use one of the better .240 diam coax types either 50 or 75 ohms
but then I starting reading about losses when mismatch exists and thought
maybe RG8 might be worthwhile.  Or will I be just as well off using the
cheap 300 ohm foam twin lead that I now use.  I don't expect much noise from
things in the house but do know the current washer is a problem when it's on
- probably has more electronic controls than the older one that I had for
years with mechanical switching.  My current system picks that up because
the lead-in wire drapes over toward the laundry room.  But I can hear it on
a portable am radio operating on its internal antenna as well.  I usually
lose interest in listening when the washing machine is running.

The new house will have some foil-covered sheathing on the roof to lessen
attic heating.  Does anyone have experience with this stuff with respect to
antennas nearby.  I don't think the metal volume is actually very great?  I
was also considering putting the antenna below the roof in the attic since
there's a long span over the garage and part of the house but wonder if this
sheathing might be a killer.  If there was a reliable way to connect to it,
perhaps it would make a good antenna itself.  That's about as big a can of
worms as I can open,  thanks for any ideas.  Maybe I should just lay a long
wire on the ground !!  Dan.