Iitoi ) writes:
I have a copy of the old ARRL "Radio Designer" software, but it does not
run on modern OS's, and ARRL has not renewed their agreement with the
author.

Can anyone recommend a similarly capable software package which will
run on an XP platform. Need not be freeware, but also cannot afford a
professional 'commercial' package.

This has come up in the past, ever since the ARRL stopped selling the
software. Go to groups.google.com and do a search of this newsgroup using
arrl "radio designer" as the searchwords. You're at least going to find
discussion about alternatives after the ARRL version left the scene. It
was apparently a truncated version of some commercial software and at
one point at least there was a free student version of that commercial
software. Read the threads, and it may be helpful finding an alternative.
Though perhaps enough time has elapsed that the alternatives mentioned
have passed into history also, or don't run on recent operating systems.

Michael VE2BVW