Rich, that was VERY well put. Even a dummy like me could understand that clearly. I think as much as your idea of the Q being on the Width control is a good one, I may actually rather put that Q setting in the Config menu. I don't see adjusting the Q as often as I would the Frequency of the APF as you described. One reason that the Shift knob is the best candidate is be because it seems that just like when you put the Dual PB filter on, the Shift is centered you are unable to adjust it, it will be the same with the APF on (or at least this is my understanding at this point). So it really wouldn't make any difference regardless. I much prefer to keep the Width control active, because I can see that I'll probably end up using that APF on almost all of the time. In that case I want to be able to still operate my Width at any given time without turning on and off my APF to do so. If it is the case where the Shift doesn't work when the APF is on, than it would be nice if in the future the Shift would retain it's setting until the operator turns off the APF and readjusts it. > Date: Wed, 27 Oct 2010 16:54:34 -0400 > From: ve3...@storm.ca > To: elecraft@mailman.qth.net > Subject: Re: [Elecraft] APF For K3 > > Here is an operational scenario: > > You are CQing in the CQ WW CW contest. There are other loud stations > CQing on either side of you. You have adjusted your SHIFT and WIDTH > controls to eliminate the adjacent-channel interference while still, you > hope, being wide enough to catch anyone calling you. > > A weak station replies to your CQ, but he's some distance off your > frequency, although still within your bandpass. You'd like to be able to > put an audio peaking filter on his signal without affecting the rest of > your setup. > > You don't want to change your sidetone pitch; that's a separate question > for a separate discussion. You don't want to use RIT or CWT, because > that will bring one of the adjacent loud signals into your bandpass. > Anyway, the desired signal is too weak to trigger CWT. Likewise, you > don't want to shift your main DSP filter bandpass (the "context"); > you've got this set up for where you are and you don't want to change it > just for this one 30-second QSO. If you didn't have an APF, you might > try narrowing the DSP filter bandwidth, but he's far enough > off-frequency that doing so would run the risk of losing his signal, > meaning you would have to fiddle with both SHIFT and WIDTH to home in on > him, and that takes time to do, plus more time to restore them after the > QSO. > > What you would really like to be able to do is to adjust an audio peak > filter's frequency so that it is on top of the received weak signal, but > without affecting the context (your DSP shift and width, your sidetone > pitch, or your transmit frequency - these should all stay where they were). > > My suggestion would be to use one of the buttons (DUAL PB seems to be a > possible candidate here) to turn the APF feature on, and while the > feature is on, the SHIFT and WIDTH controls would adjust the APF > frequency and width (or Q) and would have no effect on the context > filtering. RIT and SPLIT would still work normally, it's just SHIFT and > WIDTH that would have been subverted to do the APF adjustments while the > APF is on. If you really did want to adjust the context filter width or > shift, you would have to turn APF back off to do so. Once the QSO with > the weak station had been successfully concluded, you could either turn > APF off, or else leave it on with its width adjusted to include the > entire context bandpass, and carry on CQing. > > My 2c worth. > > 73, > Rich VE3KI > > > > ______________________________________________________________ > 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
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