On Mon, 16 Feb 2009 22:22:20 -0600, Frnak McKenney
wrote:

First, the need for impedance matching between an antenna and a
receiver. My understanding is that a resonant halfwave dipole will
have an impedance around 73 Ohms; unfortunately, unless I can obtain
research funding from the just-passed Congressional Economic
Stimulus bill I'm going to have trouble paying for 2.5km of copper
wire, some towers, a crateload or two of porcelain insulators,and
the land to build it on. (Hey, I promise to dump it back into the
economy ASAP. Really! grin!)

So any non-loop antenna I can construct will necessarily be a "short
wire" or "electrically small" antenna (two useful search terms).
But how does one go about calculating the impedance of a coat hanger
or an extension cord ("short piece of wire")?

Hi Frank,

One doesn't try.

The simple solution is the conventional one - you use a tuner.

The tuner provides the matching (providing it has sufficient
inductance and capacitance - you will have to investigate designs) and
adjacent signal rejection (which could seriously de-sense your
received signals).

Your antenna doesn't need to be very big, but it might help to have it
very remote, if there are noise sources nearby (like motors, aquarium
heaters, bottle style TVs, ...); and the line sufficiently choked. A
good ground too, tying into the service ground through a separate wire
to reduce coupling of noise from shared grounds. This last may
introduce a ground loop if your Mohican is so vintage as to have had
relaxed design standards. A little research online reveals it is
battery operable. You may want to fully exercise that option.

73's
Richard Clark, KB7QHC