Bob D. wrote:
I haven't used a Smith Chart in over 30 years, and to say the least, I'm a
bit rusty. I'm thinking there must be computer programs that can do the
calculations with values you just plugs in. Any recommendations? I'm
specifically interested in finding the impedances of antenna whips much
shorter than 1/4 wave.

Hi, Bob -

http://zaffora.f2o.org/W9DMK/W9dmk.html has one.

About 3/4 of the way down the page.

It won't help you find antenna impedance unless you plan to measure the Z at
the input end of the line and use the tool to get antenna Z. As has been
said, you can use EZNEC to model your antenna and get its impedance.

However, a Smith chart can be very useful for matching a thing to another thing.

The one I use (a demo) I got from the University of Applied Sciences in
Berne, Switzerland. I like it. However, it appears that it has been removed
from the host. If you want it, I can send it to you. It is zipped to 306 kb
in size.

Cheers,
John