[Elecraft] K3S filter for FT8?

[Barry]

Frank,
     All of FT8 is supposed to fit in a voice grade channel, 2.1 KHz 
-3.0KHz. The S/N numbers you see are referenced to a 2.5 KHz. B/W. 
However, having said that, there are some operators that go out to just 
short of 3.0 KHz. I leave my receiver open to this larger number. If 
your question is really asking what is the signal bandwidth that is a 
different question than I just answered. My recommendation is to set 
your DSP bandwidth, the knob selectable B/W, equal to the roofing filter 
B/W plus just a little and not worry too much about it. You will see the 
majority of signals and the software will see the available calls and 
stations calling you. The downside is greater interference and some AGC 
issues caused by some station you really didn't want to work anyway.

     I'm not trying to be glib in answering you in the latter part of my 
comment above, but there is no easy single answer. I do believe most 
everyone is operating as I do, within the SSB filters of their radio.

73,
Barry
K3NDM

------ Original Message ------
From: "Frank O'Donnell" <vfo77 at inkbox.net>
To: "elecraft at mailman.qth.net" <elecraft at mailman.qth.net>
Sent: 5/5/2019 5:54:34 PM
Subject: [Elecraft] K3S filter for FT8?

>I'm sure this is a well-covered question, but I'm getting so many hits on search terms that it's difficult to find past discussions.
>
>On the K3S or K3, what filter(s) are people finding optimal for FT8? Due to its popularity, it seems as though the FT8 bandwidth has been gradually widening.
>
>Thanks and 73,
>
>Frank O'Donnell K6FOD
>
>
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