I believe the demo (free!) version of EZNEC will answer your
questions. Google for it. One of the most critical aspects of any
antenna is where it is with respect to ground.
John W8CCW

On 7 Jul 2006 12:29:54 -0700, wrote:

I searched all over the Internet and many books but just could not find
a formula or rough number of a wire antenna's impedance (not dipole or
anything else, just a simple, plain wire). I need this number to match
my small transmitter's final stage output, about 10mW, at 450MHz. The
final stage's transistor has fT of 6GHz, and is not unconditionally
stable at 450MHz. So I need to match it using Smith Chart. I know those
portion of work. But I just don't know the wire's impedance's range,
say, is it in the 50-80 ohms or in the 500-600 ohms range or even
1000-2000 ohms? Right now I do not guess this number right, and my
transmitter seems always oscillating at a wrong frequency. So take an
example, if I use a wire antenna, say, 22 AWG, spools of solid, and the
length=wavelength/4, what is its approximate impedance? Thanks.
John Ferrell W8CCW