[Elecraft] Question - for Educational Purposes

[Alan Bloom]

> 2) The IIR filters have slightly steeper skirts, but ring more. The FIR 
> filters ring less but are not quite as sharp.

I believe the IIR filters ring more BECAUSE they have steeper skirts. 
As I explained in a previous message, FIR and IIR filters have similar
ringing characteristics if the bandwidth and shape factors are the same.

Al N1AL



On Thu, 2008-07-24 at 11:25, Vic K2VCO wrote:
> KB5DXY wrote:
> 
> > How about a discussion of what these filters actually do for you and why you
> > might want to use each one. 
> 
> Here is the most practical possible explanation:
> 
> 1) We are talking about the narrowest filters, 50-100 Hz. So this is 
> only applicable to CW.
> 
> 2) The IIR filters have slightly steeper skirts, but ring more. The FIR 
> filters ring less but are not quite as sharp.
> 
> 3) Find a very weak CW signal that you can barely copy and see which 
> makes it easier to copy.
> 
> Note: it will depend on band conditions; different types of QRN may make 
> one type of filter better than another.