RadioBanter - View Single Post

March 5th 04, 11:36 PM

In article , (Tom
Bruhns) writes:

Download RFSim99 and let it do it for you. Download Filter Design
from AADE's site and let it do it for you. Download NuHertz's demo
version of their filter design software and let it do it for you.
There may even be web aplets that will do it for you. And then you
can play with configurations and shape factors and the inevitable
tradeoffs between complexity and shape factor.

Or, you can ask me for a free package of LCie4 that I first wrote
back in '93 and have revised only slightly since then. DOS level,
no fancy screens or prettyness in graphics...but LCie4 allows
individual component value variations, actual unloaded Q values,
and Sensitivity (output response or input impedance) to any
specified tolerance of all-Cs or all-Ls. Works under Win98 and
WinXP.

Does 3 to 9 section Lowpass, Highpass, Bandpass, and Bandstop
and 2 to 9 section "resonator" Bandpass filters with choice of "high"
or "low" impedance coupling by C or L. Butterworth, Tchebyshev
(or Chebyshev, heh heh), or one kind of Elliptic, choice of minimum
L or minimum C configurations on odd sections (or 'orders' as some
insist on calling them).

Output Response and Input Impedance are separate analyses, not
part of the calculation of filter component Synthesis. Q of all Cs or
all Ls is frequency-independent; i.e., same specified value at all
frequencies of analysis. That's a compromise to simplify analysis;
purists want a SPICE-like thing, no doubt, where they can model
everything...:-) Chances are those purists never built a real one to
experience the joy of transmutation of paper into hardware.

A "parts listing" command yields a half-S version of a "schematic"
good enough to show the values of separate components, on-screen
or on paper. LCie4 is fast and thorough, lets one play with values
and affect on response until one gets tired of doing so. :-)

Less than 250K in total package size, sent as an e-mail attachment
in response to polite e-mail inquiry. It's free...do not ask for money
back if dissatisfied...

Len Anderson
retired (from regular hours) electronic engineer person