From: Iitoi on Wed, Nov 29 2006 7:30 pm


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.

Suggestions?

I would suggest "LTSpice" from Linear Technology. A freebie!

A full SPICE program that includes a schematic-capture option in
addition to the regular Netlist circuit entry. NO limitations on
number of parts. Some general-purpose models included in supplied
library. Runs fine on my XP Home operating system. Allows
printout of schematics, waveform-response displays from my system.

This SPICE derivative was originally supplied as a marketing aid
to demonstrate Linear's switched power-supply ICs...and apparently
someone at Linear had the bright idea to supply it as a freebie.
We can all benefit from that "marketing mistake" and enjoy a full-
on SPICE program.

I've already used it for a few months and find it matches the
commercially-packaged products from Intusoft and Orcad. Yes, it
does do oscillators without any need to add special components
to start one up. :-)

As with all SPICE derivatives, those not familiar with SPICE have
a learning curve that might be steep. By now, though, SPICE is
rather standardized and - usually - what is written about them in
the recent past will apply here. The schematic-capture drawing
function (converts automatically to a Netlist) is a bit clunky to
use but then so are the commercial programs that have that.

So far, the supplied models in LTSpice Library all seem to follow
the actual parts...such as with workhorse 2N3904 and 2N3906 and
1N4148 semiconductors, plus some others such as a few LEDs,
several standard zeners. Some of the inductors and capacitors
used with switching supplies are in the Library with reasonable
internal characteristics (ESR on electrolytics, DC resistance
and interwinding capacity on coils). One can add other SPICE
models with a supplied model-entry function but I've not tried
that yet...that be a prodigious side project. There's a couple
of websites devoted to using LTSpice already on the 'web, one of
those for modeling audio TUBE amplifiers.

www.linear.com Look in, about 5 MB FREE download.