In article et,
"Sanjaya" wrote:

I have a 50 ft. random wire (22 AWG) I use for my portable SW's. It
is indoors and just runs around the ceiling of my listening room.
Connects to the receivers with a 1/8th inch mono plug.

Now I'm looking at the Icom IC-R75 and see it needs a 500 ohm
longwire.

Is there a way to convert my random wire to function properly with
the Icom. That is, can I make it a 500 ohm wire? Alternately, can I
take it down and replace it with another wire. Since I don't know
sh*t about antennas, what makes a wire 500 ohms, and what parts,
besides the proper gauge wire, are needed?

Presently I have to keep this simple, since I can't put anything up
outside. If I move I could put up a "real" antenna outdoors, but if I
get the Icom now I'd need to use basically the same setup I use for
the portables.

Should I forget the Icom until I have a new house? Geez... then I'd
have a $100,000 shortwave radio.

If you want to e-mail a reply instead of post you can send it to
sanjaya_49 at yahoo dot com

For a random wire the RF return is the ground underneath the wire. The
farther the wire is from the ground the higher the impedance. The
smaller the diameter of the wire the higher the impedance. The lower
the conductivity of the earth under the wire (generally) the higher the
impedance of that wire.

For average earth conductivity and a 22 gauge wire the height above
ground for 500 ohms impedance would be less than 5 foot and most likely
you would want it around 2 to 3 feet off the ground.

--
Telamon
Ventura, California