Netnews Marty wrote:

Wonder if Radio Shack 21-543 uses switched capacitor filters as basis.

Google no direct help but does show Rad-Shack parts list that might
be plumbed for an answer.

Would like to move the CW center-freq. around the 750 hz place it's
currently located - per '95 Handbook wherein only a pot's needed with the
MF8CCNs in a design there.

Thnks for the read OMs

Marty aa4rm

PS... now that I've got ur attn, anyone know a 'filter' that hunts
out a hetrodyne freq. and nulls it automatically?




They exist. They've been described in QEX or QST, but I can't remember
the date. It requires making an adaptive filter on a DSP that looks for
highly correlated data and nulls it out. Supposed to work very well.

I think I've seen ads for such things, but my personal radio collection
only includes things that I built or things with vacuum tubes, so I
can't give you any specific information.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com