On Wed, 30 Mar 2005 09:19:40 -0800, Richard Clark
wrote:

[snip]

Hi All,

I have since researched the archives to find my reference:
http://users.adelphia.net/~n2pk/

What can be done, what has been done, and what might be inferred is
revealed at this page.

This is the greatest thing since sliced bread.

I've built one for ~$250.00. Here's a photo taken during construction
and checkout:

http://www.qsl.net/n7ws/ANA_1.jpg (350K)

Currently it's limited to 60 MHz although variants are in the works to
increase this. Another minor limitation is that the software is
DOS-based although Windows software is under development by other
users. Xp users, like me, have a couple of hoops to jump through to
access the parallel port but it's no big deal.

The accuracy, however, is lab quality and is comparable to commercial
network analyzers costing tens to hundreds of $K like I used to use,
although it's achieved at the expense of measurement speed.

Also see:

http://groups.yahoo.com/group/N2PK-VNA/

A higher cost alternative with much reduced dynamic range is he

http://radio.tentec.com/Amateur/vna