Pete Smith N4ZR wrote: > > I've got to agree with The Smiths (whoever they are) on this one, Bill - > the only thing I was trying to point out was that you don't need to find > yourself to the Shift knob to move the APF around, if you tune it to the > same point as your IF filter peak and tune with your RIT or the main > tuning. >
Pete I'm repeating myself but...if you tune the K3 in its normal VFO mode (not FINE) it tunes in 10 Hz steps. For extremely weak signals (for which APF is intended) you'll give up 1+ dB by not being able to peak signals that fall between the 10 Hz steps. For a signal at or below the noise floor, 1 dB can be the difference between copy and not. This is why Wayne went to 5 Hz steps instead of 10 Hz in the latest APF implementation. Of course you can also switch the VFO to FINE and tune in 1 Hz steps (which is what I did prior to the 5 Hz SHIFT mod) but 1 Hz is really overkill (...and slow). Regarding AF TUNE (...not APF) in the TS-930S, it's simply a tunable 3-pole active filter. It has NO gain and must be in the order of 80-100 Hz BW. Contrast that to the 30 Hz BW and 9 dB gain APF in the K3. I'd liken AF TUNE in the 930 to the original focus/context filter (DUAL PB for CW) in the K3 (which IMHO is not as useful as APF). 73, Bill -- View this message in context: http://elecraft.365791.n2.nabble.com/K3-APF-tp5735159p5738862.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:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
