[Elecraft] adding 250Hz filer, any improvement?

[Vic K2VCO]

I see that others have told you that you can narrow the DSP and it will be just as good as 
long as there are no nearby signals greater than about S9+20.

Let me add that a huge improvement in copyability of weak CW can be gained by using the 
APF in current firmware. It has a bandwidth (I believe) of about 30 Hz at 6 dB points, and 
also provides a slight gain boost. It's easiest to select 1 Hz tuning steps (tab 'fine') 
when tuning with it on.

I usually use a DSP bandwidth of 300-400 Hz and APF on when copying really, really weak 
signals.

I know there are guys like W4ZV who have a DSP between their ears that does a better job 
with wider bandwidths, but not all of us have this ability!

On 2/9/2011 12:07 AM, Edward R. Cole wrote:
> Let me ask a filter question for a different situation.  I am
> interested in receiving very-weak CW and currently have the 2.8 KHz
> and 400-Hz 8-pole filters.  Will narrowing the DSP bw down to 200-Hz
> work as well as using a 200-Hz filter?  There are no strong stations
> either nearby or on the band.
>
> BTW I am impressed with the 400-Hz filter on the K3 when compared to
> the 400-Hz DSP on my FT-847 (no surprise).
> I find trying to hear extremely weak-CW that narrowing down to 200,
> 100 or even narrower makes the difference.
>
> I left a blank filter space on the main receive for adding a narrow
> SSB filter at a later time.  I also have the 13-KHz filter for
> FM/AM.  Sub-Rx has 2.8 and 13-KHz.
>
>
> 73, Ed - KL7UW, WD2XSH/45
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-- 
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco/