If you have an SDR type panadaptor using the IF out signal, you can try a peaking filter by downloading and running WinRad software. WinRad has a peaking filter that works great.
Frank - W4NHJ ----- Original Message ----- From: "Bill Tippett" <btipp...@alum.mit.edu> To: <elecraft@mailman.qth.net> Sent: Sunday, August 16, 2009 7:38 AM Subject: Re: [Elecraft] APF vs 10 Hz DSP, why they don't sound the same > > More generally, the APF proponents seem to have the problem that they > treat it almost as magic. If they could characterise what it does in > terms of filtering, AF gain adjustment, distortion etc. it should be > possible to simulate it in DSP, subject only to having enough processing > power. In particular, peaking just seems to me to mean turning up the > AF gain in parallel with reducing the bandwidth. If that is all that it > is doing, and if the K3 has soft AF gain controls, a plugin box could > issue both commands in parallel. > > The circuit in question is on page 54 of the FT1000 schematic > below: > > <http://www.radioamateur.eu/schemi/FT1000_user.pdf>http://www.radioamateur.eu/schemi/FT1000_user.pdf > > The APF is around Q3016-2 (including Rs 3062, 3065, 3067 per the > "un-modification" sheet on N1EU's website below). The circuit > schematic above has *not* been modified to the (incorrect) values > shown in the Yaesu service bulletin. > > http://n1eu.com/Mods/apf.pdf > > The FT-1000's APF is generally regarded by many as the best APF ever > done. It should be possible to plug this into a circuit simulator > and generate a frequency response plot that Lyle can emulate in the > DSP. I have a feeling that this is a very narrow and high-Q response > that is on the verge of ringing, but it should be possible to > duplicate the circuit in the DSP. > > 73, Bill W4ZV > > > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
