Subject: Re: [Elecraft] RTTY filter for K3

[Art]

I must be confused by this filter discussion. Is not a Nyquist filter by 
its very definition a digital filter? Not directly comparable to the 
crystal filters in the K3 or any other rig.

I would have supposed a Nyquist filter is one that samples at least 
twice per cycle at the highest observed frequency.

As to what comes out of crystal filters, i.e. rtty tones, different 
discussion. If I have the processing chain figured correctly crystal 
filter output is then sampled by the audio card.

I'm not a filter designer. Just asking based on previous experiences.

73 Art