[sdiy] RC filter questions + SPICE RC filter simulationquestions

[Tim Stinchcombe]

> > Can you put up some plots showing the frequency response, and in 
> > particular the bump you refer to?
> 
> Of course. I was going to, and even saved off the images, but 
> my internet died so I got sidetracked. :-) Here they are:
> 
> plots: http://img709.imageshack.us/gal.php?g=rc001.gif

I didn't do anything more than run a simulation to verify your results, and
also ran a pole-zero analysis in SPICE (not regarded as particularly
reliable I believe - it suggests there are some zeroes around, but it also
gave *5* poles for the whole, so I take it with a pinch of salt!): but I see
your bump, and I'm guessing that you will get more like what you are
expecting to see if you use a _logarithmic_ scale for the y-axis (?!).

Tim
__________________________________________________________
Tim Stinchcombe 

Cheltenham, Glos, UK
email: tim102 at tstinchcombe.freeserve.co.uk
www.timstinchcombe.co.uk