This may be a reasonable representation of the concept ? http://www.ab4oj.com/icom/ic7600/apf.html
~Iain / N6ML On Sun, Oct 24, 2010 at 4:55 PM, Ron D'Eau Claire <r...@cobi.biz> wrote: > According to Icom (who has it on some of their rigs): > > "The APF changes the audio frequency response by > boosting a particular frequency to enhance a desired > CW signal... The peak frequency can be adjusted" > > So this is an adjustable frequency audio filter such as we've used for the > past 3/4 century. > > As Doug, KR2Q, noted, the K3 is capable of a 50 Hz bandpass. That's about as > narrow as a CW signal being keyed at 20 or 30 wpm can be fit into. Narrower > will attenuate the CW sidebands so the dots and dashes start "slurring" > together. > > I've used an audio filter many times and found them of very limited value to > me if the receiver has a decent I.F. bandpass characteristic. > > That said, if it it's reasonable to implement, people want it, and it can be > switched out, I'm all for it. > > Ron AC7AC > > ______________________________________________________________ > 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