Dana wrote:
Looking to notch out a 400HZ whine from some audio circuits connecting
remote manned sites to a central location.
(Snip)
Problem with that is getting the inductors locally.
Up here In Fairbanks our choices are very limited.

Thanks.

Synthesize your inductor with a Gyrator!
Here is a schematic for a graphic equalizer section using virtual
inductors. Extremely cool if it works.

http://www.4qdtec.com/graph.html

--Winston