Don: Thanks for the tip on the NR and Dual Passband! Never thought about doing that! Just tried it. The only thing is that its not variable, which is sometimes useful in a contest pileup. And you can change the pitch, but, like my previous post about Icom's pitch, you have to remember to set it back to "normal" as there is no CLR button. But it does what I think APF should do, which is peak a certain tone in the context of other signals.
Maybe I can finally pack up the ancient QF-1 and take it to the next Hamfest! -lu- w4lt- Message: 17 Date: Sun, 24 Oct 2010 15:14:45 -0400 From: Don Wilhelm <w3...@embarqmail.com> Subject: Re: [Elecraft] APF For K3 To: Paul Christensen <w...@arrl.net> Cc: elecraft@mailman.qth.net Message-ID: <4cc485a5.4040...@embarqmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed I have never used a receiver with a button labeled APF, but I have used my K2 with an audio filter. It seems to me the only other characteristic of APF is that the center frequency can be changed. On the K3, we have the Dual Passband that may work in a similar manner. Set the width to the lowest value 50 Hz and turn on Dual PB and you have a wide filter with a peak at your sidetone pitch. You can change the Pitch if you wish to peak a different audio frequency, but for the life of me, I cannot imagine why anyone would want to peak any pitch other than his preferred sidetone pitch. If you want a little more peaking, turn on NR and set it to an aggressive setting. The way NR works is that it builds a narrow filter around a signal that it thinks is a valid signal - so you have a filter at the audio pitch where you have set the VFO. Yes, the K3 is different than those receiver that have APF, but in my opinion, it accomplishes the same thing, but differently. 73, Don W3FPR No virus found in this outgoing message Checked by PC Tools AntiVirus (6.1.0.25 - 6.14880). http://www.pctools.com/free-antivirus/ ______________________________________________________________ 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