[Elecraft] NB and NR algorhythm

[Wayne Burdick]

Hi Tony,

I use APF constantly and find that it makes weak signals buried in  
noise far more readable. That is its purpose. The center frequency is  
tunable in 5-Hz steps, but we feel that the narrow bandwidth at peak  
is critical to its success, so we haven't tried making the bandwidth  
variable. I can see how it might help with faster CW speeds, however.

Lyle's algorithm is an emulation of the most successful hardware APF  
circuits and was based on extensive research. We also routinely get  
compliments on how well it works. So I'm surprised that it isn't  
working as well for you.

I'm sure you'll get other opinions, too.

73,
Wayne
N6KR

On Nov 14, 2011, at 6:36 PM, ANTHONY JAPHA wrote:

> I'd like to add a similar suggestion, this one about the APF in the  
> K3.  I accept that it works as intended, but it is not useful.  I've  
> used APFs for many years and they can be very useful.  The need to  
> severely narrow the bandwith to avoid ringing and the poor peak in  
> the audio when the APF is peaked limit the current filter.
>
> What I'd like to see is an APF that does not depend on a narrow  
> bandwidth and that has a pronounced (tunable) peak at the desired  
> frequency.  It does not need to be extremely sharp, but it could be  
> if that is dictated by design considerations.  And, to keep it  
> simple, there also does not need to be a choice of bandwidth through  
> the menu,
>
> I'd like to hear others' ideas.
>
> 73,
> Tony, N2UN
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Elecraft at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html