Ron D'Eau Claire wrote: > > 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. >
Ron, when I read this I didn't think it sounded like the KAF2 I have, so I checked the manual (you wrote it?) Per the specifications: BPF Bandwidth: 80 Hz @ -3 dB; 270 Hz @ -20 dB Gain: 0-1 dB in OFF (LPF only) and AF1 (first CW filter stage) modes, slightly higher in AF2 mode (both stages). Contrast this to the K3's APF: BPF with 30 Hz @ -3 dB and gain of +9 dB. http://sites.google.com/site/ft1000apf/w6lxanalysisoftheapfcircuitintheft-1000 (see Slide #3) The KAF2 is a typical audio bandpass filter like those found in many rigs (e.g. TS-930S, etc). The K3 APF is an entirely different animal based on the FT-1000D's highly acclaimed APF. I've never found the KAF2 to be very effective but the K3's can be quite effective in certain cases (but not all). 73, Bill -- View this message in context: http://elecraft.365791.n2.nabble.com/K2-APF-implementation-tp5783119p5786449.html Sent from the [K3] mailing list archive at Nabble.com. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
