[Elecraft] Roofing filters and DSP bandwidth tuning

[john at kk9a.com]

I have 8 pole 400 Hz filters in my K3s's, not 500 Hz as well as 250 Hz.
According to W0YK's presentation linked below the 400 filter has a bandwidth
of 435 and the 250 filter has a bandwidth of 370. This data is for 8 pole
crystal filters made by Inrad, I am not sure what filters Elecraft currently
sells. 

http://www.nccc.cc/archived_meetings/pdf/K3%20Filters,%20Jan%202009.pdf  

John KK9A


Jim Brown K9YC wrote:

On 1/27/2021 12:14 PM, john at kk9a.com wrote:
> FWIW, I have both the 400 and 250 8 pole filters. If money is an issue, 
> I believe that there is very little bandwidth difference between the two.

I have both as well in all my radios. I can clearly hear the difference 
when switching between them. I mostly use the 250 Hz filter for CW and 
the 500 Hz filter for RTTY.

73, Jim K9YC