Narrow-Bandwidth Television Association

I came across this site that has several useful utilities for designing LPF and HPF filters.

LPF:
http://www.beis.de/Elektronik/Filter/ActiveLPFilter.html

HPF:
http://www.beis.de/Elektronik/Filter/ActiveHPFilter.html

Main site:
http://www.beis.de/Elektronik/Electronics.html

The default gain for each stage is unity but other gains may be selected.

I've found it useful in designing anti-alias filters for NBTV,

Regards,

Graham

An alternative is from Texas, sadly Windoze only but it does include Bessel, Chebychev, Butterworth, Linear Phase and custom filters, in both low and high-pass configurations...as many poles as you can shake a stick at. In either MFB (multi-feedback) or Sallen-Key and at any sane gain from unity upwards. The good thing is it's free...

http://www.ti.com/tool/filterpro

I think it was highlighted in a recent newsletter...

Steve A.

P.S. Good to see you around Graham...

Hi Steve,

That's a useful design tool as well,
thanks.

Graham