[Elecraft] RE: Elecraft] When Filters Don't Help...

[Paul]

Thanks Ron. Your explanation certainly tracked with my experience - 
but I wasn't quite sure why. I was thinking the razor sharp "narrow" 
pass was the best - but by limiting the noise to also that narrow 
frequency, I've sort of created my own QRN. Some older audio filter 
designs have sort of a reverse notch. Instead of dropping out a 
narrow tone, you can boost it. By keeping the background "white 
noise", you could then lower the level, bringing it to minimum, and 
still hear the CW. But going to far in that directions creates the 
same CW + Noise  tone again.
73,
Paul K7NHB