[Elecraft] K2 APF implementation?

[jeff martin]

My thinking was to ustilize the existing KDSP2 menu structure to adjust the filter. Something like add a CW filter selection of "APF" to the existing selections, and then menus to select center freq, Q and gain.
One thing I have done to emulate this is to set the existing CW filters to various bandwidths, and then with the center freq at my chosen sidetone pitch, increase the gain setting to peak the filter. Sometimes I'll turn on the noise reduction as well. In some cases it has been a bit startling how a Q2 or 3 signal can become comfortable copy. The only problem with the method is that it requires a lot of button pushing and you cannot really store the resulting filter (the gain control affects all of the CW filters) as a separate entity.

--- On Mon, 11/29/10, Ken Alexander <k.alexander at rogers.com> wrote:

> From: Ken Alexander <k.alexander at rogers.com>
> Subject: Re: [Elecraft] K2 APF implementation?
> To: elecraft at mailman.qth.net, "Ron D'Eau Claire" <ron at cobi.biz>, "jeff martin" <n7krt_1 at yahoo.com>
> Date: Monday, November 29, 2010, 6:47 AM
> When you consider that the K2's
> buttons have two and sometimes three  different
> functions already (there's a clock in there?  Really?)
> I would prefer to have an outboard audio filter like the
> AF-1.  Plus you need a knob or two and I don't think it
> would be very easy to retrofit extra knob functions into the
> existing radio.
> 
> I'd like one too, but I don't think it's practical in the
> K2.  Maybe in the K2.1!   8-)
> 
> 73,
> 
> Ken Alexander
> VE3HLS
> 
> 
> 
> --- On Mon, 11/29/10, jeff martin <n7krt_1 at yahoo.com>
> wrote:
> 
> > From: jeff martin <n7krt_1 at yahoo.com>
> > Subject: Re: [Elecraft] K2 APF implementation?
> > To: elecraft at mailman.qth.net,
> "Ron D'Eau Claire" <ron at cobi.biz>
> > Date: Monday, November 29, 2010, 8:47 AM
> > Ron,
> > Great idea! I agree that the AF-1 would do the trick,
> but
> > was hoping that something integrated into the existing
> K2
> > firmware/hardware could be implemented. If that
> doesn't pan
> > out, I'll opt for the AF-1.
> > 
> > Jeff 
> > 
> > --- On Sun, 11/28/10, Ron D'Eau Claire <ron at cobi.biz>
> > wrote:
> > 
> > > From: Ron D'Eau Claire <ron at cobi.biz>
> > > Subject: RE: [Elecraft] K2 APF implementation?
> > > To: "'jeff martin'" <n7krt_1 at yahoo.com>,
> > elecraft at mailman.qth.net
> > > Date: Sunday, November 28, 2010, 8:19 PM
> > > Jeff, I have compared the K3's APF
> > > with the filter offered in Elecraft's
> > > AF-1 Active Filter mini-module kit. There is no
> > difference
> > > I can hear in the
> > > performance. Actually the AF-1 has more
> flexibility
> > since
> > > you have two
> > > levels of "Q" to choose from, variable gain, and
> an
> > > independent variable
> > > low-pass filter function. 
> > > 
> > > At $60, it's a great little filter.
> > > 
> > > For an old vacuum-tube jockey like me it's
> satisfying
> > to
> > > see digital gear
> > > struggling to do something as well as analog
> circuits,
> > Hi!
> > > I'll hand it to
> > > Lyle; he succeeded with the APF. It's darn near
> as
> > good as
> > > the AF1.
> > > 
> > > Ron AC7AC
> > > 
> > > -----Original Message-----
> > > From: elecraft-bounces at mailman.qth.net
> > > [mailto:elecraft-bounces at mailman.qth.net]
> > > On Behalf Of jeff martin
> > > Sent: Sunday, November 28, 2010 6:37 PM
> > > To: elecraft at mailman.qth.net
> > > Subject: [Elecraft] K2 APF implementation?
> > > 
> > > Any chance we might see an implementation of 
> APF
> > for
> > > the audio-based DSP of
> > > the K2? I realize it might require swapping out
> U3 to
> > > implement the change.
> > > I would even give up some of the other
> functionality
> > if
> > > adequate memory
> > > resources don't exist to implement an additional
> > function.
> > > 
> > > Any interest?
> > > 
> > > Jeff
> > > N7KRT
> > > 
> > > 
> > 
> > 
> >       
> >
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