Also, you can move the "peak" left/right by rotating the SHIFT knob. You will see APF setting appear in the VFO B area and the ref point is denoted by an "*" next to 45.
Sent from my iPhone ...nr4c. bill > On Feb 5, 2016, at 10:27 AM, David Kuechenmeister <n...@bellsouth.net> wrote: > > Thanks. I'll try again and be very careful this time. > vy 73,Dave N4KD > > On Friday, February 5, 2016 10:08 AM, Barry N1EU <n1eu.ba...@gmail.com> > wrote: > > > The receiver has to be tuned precisely to the signal in question for APF to > work. > > 73, Barry N1EU > > On Fri, Feb 5, 2016 at 9:53 AM, David Kuechenmeister <n...@bellsouth.net> > wrote: > >> I tried this the other day with no success. That is, the weak signal that >> was barely detectable, became so buried in ringing that I couldn't detect >> it at all. I think I followed the procedure outlined in Wayne's email >> below... >> Noise was around S5 on 40m and the K3 was configured with APF active. I >> had my 500 Hz filter selected and varied the DSP WIDTH from 500 to 300 >> without substantial improvement. FINE tuning selected. >> What am I forgetting? >> vy 73,Dave N4KD >> >> On Tuesday, February 2, 2016 9:36 AM, Wayne Burdick <n...@elecraft.com> >> wrote: >> >> >> Hi all, >> >> This morning I was hearing lots of very weak signals in the 40-meter CW >> band, right at today's noise floor of about S-5. (Among others, I copied >> BG4GOV in Shanghai.) >> >> Many of the signals were not copyable until I turned on APF (audio peaking >> filter). This filter's center peak is very narrow (around 30 Hz), but the >> response broadens out quickly below the 3-dB points in the curve. This >> brings up the desired signal without allowing noise to cause >> ringing--something often heard with narrow filters of the "brick-wall" >> variety. On a noisy band, the effect is just short of magic. >> >> APF is very narrow, so you'll need to tune in 1-Hz increments when it is >> turned on. Also, APF works best when used with a DSP/crystal filter WIDTH >> setting of 300-500 Hz. >> >> Use of APF differs for the three transceivers. >> >> KX3: 1-Hz tuning is selected automatically on the when the APF switch is >> pressed. >> >> K3/K3S: APF is accessed via a hold of the XFIL switch. This function is >> labeled "APF" on a K3S, or "DUAL PB" on the K3). Use CONFIG:DUAL PB to make >> sure the selected filter function is APF. See the K3/K3S owner's manual for >> a description of the alternate setting. 1-Hz tuning can be selected by >> tapping FINE. >> >> You might want to give APF a try if you haven't already. >> >> 73, >> Wayne >> N6KR >> >> __________________________ ______________________________________________________________ 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 Message delivered to arch...@mail-archive.com
