Re: [Elecraft] APF on CW
> The APF function on my KX3 makes the signal jump out of the noise > > Hope the feature remains in the K4 line It does. There are now two bandwidth settings, too. Wayne > > Regards, Jan K1ND ~ stay-safe ~ > > > -- > This email has been checked for viruses by AVG. > https://www.avg.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 > Message delivered to n...@elecraft.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 Message delivered to arch...@mail-archive.com
[Elecraft] APF on CW
January is SKCC K3Y month ~ come join us for some straight key (or bug) CW fun~ The APF function on my KX3 makes the signal jump out of the noise Hope the feature remains in the K4 line Regards, Jan K1ND ~ stay-safe ~ -- This email has been checked for viruses by AVG. https://www.avg.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 Message delivered to arch...@mail-archive.com
Re: [Elecraft] APF Primer?
The K3 APF has a very sharp peak (about 30 Hz @ 3 dB) but broader shoulders (about 300 Hz wide). It is not in the AGC loop, so any signals inside the bandwidth set by the bandwidth control may activate the AGC. Therefore, if you have nearby strong signals, you should reduce the bandwidth to keep them from affecting the signal you are peaking with the APF. But if you reduce the bandwidth below 300 Hz, then you will cut into the shoulders. This starts to have a negative effect on CW intelligibility. For some biological reason that I don't understand, the "context" provided by the shoulders helps overcome the ringing effect of the very narrow peak. High noise levels also negatively impact the usefulness of the sharp peak, because of the ringing. 73, Victor, 4X6GP Rehovot, Israel Formerly K2VCO CWops no. 5 http://www.qsl.net/k2vco/ On 25/08/2020 23:49, Fred Jensen wrote: Kevin: 1) For a K3, APF seems to be very dependent on current AGC action. If there are very strong signals close in and the AGC is doing its thing, APF doesn't seem to work. You can adjust the AGC parameters, however my experience is that I use APF infrequently enough that it's better to adjust the AGC to non-APF situations. 2) The APF will ring, it is very narrow. With APF on, using a wider DSP BW [400 or 500 Hz] will help some. Tuning just off the peak, if possible, can also help although even at 1 Hz tuning, sometimes that's hard. 73, Fred ["Skip"] K6DGW Sparks NV DM09dn Washoe County On 8/24/2020 7:33 PM, kevinr wrote: I have used APF a number of times. Sometimes it worked, but often the ringing makes it hard to hear anything intelligible. I have a two families of questions to hopefully remedy my problem. 1) What are the best band conditions to try APF? Does it work under medium QSB against medium to high noise levels? Is it better on 80, 40, or 20 meters? 2) What are the procedures to use APF on your K3, KX2, KX3, etc.? How should I set the bandwidth of the filter I'm already using? How do I peak the APF performance? Does the set up change on a per band basis or does one setting fit all cases? As I mentioned, I have gotten it to work well a few times, but usually the signal sounds buried in a hard walled well. Then I get emails telling me how well it worked during ECN. My interest is renewed, hence my questions. Help? Kevin. KD5ONS __ 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
Re: [Elecraft] APF Primer?
Kevin - Here's my take on the APF. I use it a lot during QRP Fox Hunts and I just used it to pull G3SED out of the weeds on 20. Best conditions are when only random band noise is in the passband for my technique although it can be used in conjunction with the NB (the IF blanker, not the DSP option). The passband should be QRM free. I set the DSP passband to about 700 Hz and turn on NR set to NRm5-3 or so. This is fairly light noise reduction with a level of unprocessed noise+signal mixed in. Since there is only random noise in the passband that level of NR works well. I use this to tune around looking for the Fox. When I find a signal of interest, I turn on the APF and peak the signal in the very narrow passband using FINE tuning. I also frequently use an audio spectrum display on the PC to center the signal on the marker which is set to the CW pitch frequency. Although the APF is very narrow: ~30 Hz at -3 dB, the sharp peak is more like 5 Hz wide so FINE tuning is needed and the marker helps because my ears aren't that good at matching pitch. You can set the DSP filter narrower than 700 Hz to eliminate some QRM but that seems to be the sweet spot for the NR to work well. To your other questions ... Make sure the noise level is not activating the AGC or it will be working against you. Really no band preference but it's better not to have big static crashes to deal with. Set AGC to fast if there are. It took me a while to figure this out. Have fun! 73, Brian, K0DTJ -Original Message- From: "kevinr" Sent: Monday, August 24, 2020 19:33 To: "Elecraft Reflector" Subject: [Elecraft] APF Primer? 1) What are the best band conditions to try APF? Does it work under medium QSB against medium to high noise levels? Is it better on 80, 40, or 20 meters? 2) What are the procedures to use APF on your K3, KX2, KX3, etc.? How should I set the bandwidth of the filter I'm already using? How do I peak the APF performance? Does the set up change on a per band basis or does one setting fit all cases? __ 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
Re: [Elecraft] APF Primer?
Kevin: 1) For a K3, APF seems to be very dependent on current AGC action. If there are very strong signals close in and the AGC is doing its thing, APF doesn't seem to work. You can adjust the AGC parameters, however my experience is that I use APF infrequently enough that it's better to adjust the AGC to non-APF situations. 2) The APF will ring, it is very narrow. With APF on, using a wider DSP BW [400 or 500 Hz] will help some. Tuning just off the peak, if possible, can also help although even at 1 Hz tuning, sometimes that's hard. 73, Fred ["Skip"] K6DGW Sparks NV DM09dn Washoe County On 8/24/2020 7:33 PM, kevinr wrote: I have used APF a number of times. Sometimes it worked, but often the ringing makes it hard to hear anything intelligible. I have a two families of questions to hopefully remedy my problem. 1) What are the best band conditions to try APF? Does it work under medium QSB against medium to high noise levels? Is it better on 80, 40, or 20 meters? 2) What are the procedures to use APF on your K3, KX2, KX3, etc.? How should I set the bandwidth of the filter I'm already using? How do I peak the APF performance? Does the set up change on a per band basis or does one setting fit all cases? As I mentioned, I have gotten it to work well a few times, but usually the signal sounds buried in a hard walled well. Then I get emails telling me how well it worked during ECN. My interest is renewed, hence my questions. Help? Kevin. KD5ONS __ 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
[Elecraft] APF Primer?
I have used APF a number of times. Sometimes it worked, but often the ringing makes it hard to hear anything intelligible. I have a two families of questions to hopefully remedy my problem. 1) What are the best band conditions to try APF? Does it work under medium QSB against medium to high noise levels? Is it better on 80, 40, or 20 meters? 2) What are the procedures to use APF on your K3, KX2, KX3, etc.? How should I set the bandwidth of the filter I'm already using? How do I peak the APF performance? Does the set up change on a per band basis or does one setting fit all cases? As I mentioned, I have gotten it to work well a few times, but usually the signal sounds buried in a hard walled well. Then I get emails telling me how well it worked during ECN. My interest is renewed, hence my questions. Help? Kevin. KD5ONS - __ 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
[Elecraft] APF on RTTY and TrueTTY
Hi! I have tried to solve the problem when using TrueTTY and K3s APF. Everything works fine without APF (using rev data) but if I turn APF on I lose all the tracks on the waterfall. I have tried all mark and shift combination. APF works ok with MMTTY but it is too clumsy program for me so that's why I want to use TrueTTY. MMTTY use LSB and Truetty use USB. I have tried to turn TrueTTY to reverse (LSB) no luck. Any solution? 73's John OH3SR __ 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
Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3
Thanks for all the discussion on the APF. I've got a technique now and I think I can refine it into something useful. vy 73,Dave N4KD On Saturday, February 6, 2016 8:02 AM, Chuck Guenther wrote: I've been using APF in my K3 since it was in Beta testing. I love it! I've found it necessary to use both the shift and Fine tuning-- these are not optional for effective use of APF. I've been using macros to engage and dis-engage the APF. One reason I keep combing through the Elecraft Reflector postings is for gems such as Brian's suggestion below. There is always something new to learn. Thanks, Brian. 73, Chuck NI0C KX1, K2-10, K3 Quote: The technique I'm using with the APF also involves NR like so: On an uncrowded band, set the DSP BW to 700 to 1000 Hz. If you have a roofing filter in that range stay within it. Turn on NR set to mF5-3 or there about. The wide BW helps the NR work well. The "mix" mode lets a little unprocessed signal+noise through. This is a good weak signal search mode. When you find a signal you want to copy, turn on APF and peak it in the filter. Fine tuning helps. There is little ringing because NR has reduced the noise amplitude. You can decrease the DSP BW a little but the NR is more effective with uncorrelated noise. This technique has gotten me many pelts in the QRP Fox Hunts. 73, Brian, K0DTJ __ 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 n...@bellsouth.net __ 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
Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3
I have heard people using voice synthesizers on voice modes. I believe they have had issues which keep them for speaking and this is their way of being able to get on the air. It is certainly my way of doing 25+ wpm DX contacts, but I keep trying to learn. I also QSOed with a guy on PSK31 who couldn't type and could only run macros. He mentioned his issue in one of his macros. 73 Bill AE6JV On 2/7/16 at 11:51 AM, r...@cobi.biz (Ron D'Eau Claire) wrote: Listening to keyers and keyboards on rigs with pristine keying characteristics is to me a lot like listening to a phone band filled with identical computer-generated "voices". (Stand by, that will come, Hi!) --- Bill Frantz| Concurrency is hard. 12 out | Periwinkle (408)356-8506 | 10 programmers get it wrong. | 16345 Englewood Ave www.pwpconsult.com |- Jeff Frantz | Los Gatos, CA 95032 __ 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
Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3
Strangely enough, I miss the wide open no filters receiver of my young SWL days. Probably listening in a 5kHz bandwidth with a homebrew Q Multiplier for selectivity. I somehow had a much better sense of band conditions, superseded now with internet propagation tools. Today with DSP, NR, NB, and brick wall filters it's perhaps all too clinical. On my K3 I sometimes open up the filters to really listen to what's going on around me. Nostalgia? 73, Deni - F5VJC On 7 February 2016 at 20:51, Ron D'Eau Claire wrote: > Me too. Actually, I miss small variations we used to see regularly on the > CW > bands - slight chirp on some sigs, variations in keying by people using > bugs > and hand keys, etc. Gone are the days one could tune across the bands and > recognize individual operators and their rigs after hearing just a few > characters. > > All we have left is a little noise to create a listening "environment". > > Listening to keyers and keyboards on rigs with pristine keying > characteristics is to me a lot like listening to a phone band filled with > identical computer-generated "voices". (Stand by, that will come, Hi!) > > 73, Ron AC7AC > > -Original Message- > From: Elecraft [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of > F5vjc > Sent: Sunday, February 7, 2016 4:56 AM > To: Bill W4ZV > Cc: Elecraft Reflector > Subject: Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3 > > Well actually I prefer copying CW with a certain amount of noise present. > Pure tone, no noise CW, as from a practice oscillator or an S9++ signal > quickly becomes boring and I loose concentration(or something). > It's perhaps why I prefer to dig out weak signals (ESP) from the noise on > the band. > However I do really appreciate the tools available in the K3 to do this :) > APF works great if you really learn how to use it. > > Any one else? > > > 73, Deni - F5VJC > > > __ 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
Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3
Me too. Actually, I miss small variations we used to see regularly on the CW bands - slight chirp on some sigs, variations in keying by people using bugs and hand keys, etc. Gone are the days one could tune across the bands and recognize individual operators and their rigs after hearing just a few characters. All we have left is a little noise to create a listening "environment". Listening to keyers and keyboards on rigs with pristine keying characteristics is to me a lot like listening to a phone band filled with identical computer-generated "voices". (Stand by, that will come, Hi!) 73, Ron AC7AC -Original Message- From: Elecraft [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of F5vjc Sent: Sunday, February 7, 2016 4:56 AM To: Bill W4ZV Cc: Elecraft Reflector Subject: Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3 Well actually I prefer copying CW with a certain amount of noise present. Pure tone, no noise CW, as from a practice oscillator or an S9++ signal quickly becomes boring and I loose concentration(or something). It's perhaps why I prefer to dig out weak signals (ESP) from the noise on the band. However I do really appreciate the tools available in the K3 to do this :) APF works great if you really learn how to use it. Any one else? 73, Deni - F5VJC __ 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
Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3
Well actually I prefer copying CW with a certain amount of noise present. Pure tone, no noise CW, as from a practice oscillator or an S9++ signal quickly becomes boring and I loose concentration(or something). It's perhaps why I prefer to dig out weak signals (ESP) from the noise on the band. However I do really appreciate the tools available in the K3 to do this :) APF works great if you really learn how to use it. Any one else? 73, Deni - F5VJC On 6 February 2016 at 12:19, Bill W4ZV wrote: > N1EU wrote > > I suspect that when the K3 APF was first engineered, the Yaesu FT-1000D > > APF > > (original hi-Q version) was used as the model because many prominent > > dx'ers/topbanders always raved about it. > > I lifted the "original" FT-1000D APF from the schematic in 2009 and Al W6LX > did a circuit simulation on it. Al's description provided the roadmap for > what Elecraft eventually implemented in the K3's DSP in 2010. > > http://www.mail-archive.com/elecraft%40mailman.qth.net/msg105227.html > > As Wayne has suggested previously, APF works best if you use a relatively > wide DSP setting (I use 400 Hz). I trick my K3 into using my 200 Hz XFIL > at > DSP=400 by setting the XFIL BW to 400 (similar idea to what Wayne recently > suggested with the 2.7/2.8 XFIL for better NB). The wider DSP BW keeps the > ringing down and gives your ear/brain a better background to discriminate > signals through the 30 Hz APF without ringing while the wide (5 pole) 200 > Hz > XFIL still gives good protection from nearby strong signal overload. > Setting the VFO is not as critical compared to narrow DSP settings, and I > use APF virtually all the time...even in contests. This signal path may > help visualize what I'm doing: > > signal >> 200 Hz XFIL >> 400 Hz DSP >> 30 Hz APF >> ear/brain > > 73, Bill W4ZV > > > > -- > View this message in context: > http://elecraft.365791.n2.nabble.com/APF-audio-peaking-filter-on-the-K3-K3S-KX3-tp7613416p7613632.html > Sent from the Elecraft 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 > Message delivered to foxfive@gmail.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 Message delivered to arch...@mail-archive.com
[Elecraft] APF (audio peaking filter) on the K3/K3S/KX3
I've been using APF in my K3 since it was in Beta testing. I love it! I've found it necessary to use both the shift and Fine tuning-- these are not optional for effective use of APF. I've been using macros to engage and dis-engage the APF. One reason I keep combing through the Elecraft Reflector postings is for gems such as Brian's suggestion below. There is always something new to learn. Thanks, Brian. 73, Chuck NI0C KX1, K2-10, K3 Quote: The technique I'm using with the APF also involves NR like so: On an uncrowded band, set the DSP BW to 700 to 1000 Hz. If you have a roofing filter in that range stay within it. Turn on NR set to mF5-3 or there about. The wide BW helps the NR work well. The "mix" mode lets a little unprocessed signal+noise through. This is a good weak signal search mode. When you find a signal you want to copy, turn on APF and peak it in the filter. Fine tuning helps. There is little ringing because NR has reduced the noise amplitude. You can decrease the DSP BW a little but the NR is more effective with uncorrelated noise. This technique has gotten me many pelts in the QRP Fox Hunts. 73, Brian, K0DTJ __ 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
Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3
N1EU wrote > I suspect that when the K3 APF was first engineered, the Yaesu FT-1000D > APF > (original hi-Q version) was used as the model because many prominent > dx'ers/topbanders always raved about it. I lifted the "original" FT-1000D APF from the schematic in 2009 and Al W6LX did a circuit simulation on it. Al's description provided the roadmap for what Elecraft eventually implemented in the K3's DSP in 2010. http://www.mail-archive.com/elecraft%40mailman.qth.net/msg105227.html As Wayne has suggested previously, APF works best if you use a relatively wide DSP setting (I use 400 Hz). I trick my K3 into using my 200 Hz XFIL at DSP=400 by setting the XFIL BW to 400 (similar idea to what Wayne recently suggested with the 2.7/2.8 XFIL for better NB). The wider DSP BW keeps the ringing down and gives your ear/brain a better background to discriminate signals through the 30 Hz APF without ringing while the wide (5 pole) 200 Hz XFIL still gives good protection from nearby strong signal overload. Setting the VFO is not as critical compared to narrow DSP settings, and I use APF virtually all the time...even in contests. This signal path may help visualize what I'm doing: signal >> 200 Hz XFIL >> 400 Hz DSP >> 30 Hz APF >> ear/brain 73, Bill W4ZV -- View this message in context: http://elecraft.365791.n2.nabble.com/APF-audio-peaking-filter-on-the-K3-K3S-KX3-tp7613416p7613632.html Sent from the Elecraft 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 Message delivered to arch...@mail-archive.com
Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3
I followed my interpretation of Wayne's instructions when trying to copy VP8SGI on 80M. I have an inverted V antenna with the peak at about 12 meters (44'). When I started, I could barely hear him. When I got the APF tuned in, I could hear him clearly, and actually managed to work him with 100W. I had to send my call 5 0r 6 times before AA7A, the op on the other end got it, but I could easily hear when he got it. To pull me out of the muck means he must be really good. When it worked well for me, there were no signals near the DX, and it worked with less ringing than going to a 50 Hz DSP bandwidth. I find when the CW gets up above about 25 WPM, the ringing makes it more difficult to interpret, although honestly, 30 WPM is well above my CW speed of competency. 15 is more like it for English text (W1AW practice). On the other hand, if there are nearby signals -- and I am using a 2.1KHz roofing filter when I have APF on -- then narrowing the DSP to 50 or 100Hz with the 250Hz roofing filter seems to work better. 73 Bill AE6JV --- Bill Frantz|"Web security is like medicine - trying to do good for 408-356-8506 |an evolved body of kludges" - Mark Miller www.pwpconsult.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 Message delivered to arch...@mail-archive.com
Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3
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 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 > 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 > 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 >> 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
Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3
Stephen is correct. Several of us lobbied for an APF feature shortly after the K3 debuted in 2007, drawing on our experiences with the FT-1000D. There /were/ two firmware versions that Wayne developed, and the consensus among some of us was that the first one was better than the second. As I recall, the second version cleaned up some artifacts and unintended consequences, but, we felt, at the cost of diminished "peaking." Wayne was adamant that the APF part of the code was not touched. We eventually chalked up the difference between the two versions to subjectivity among the testers and left it at that. Barry, by the way, is also correct in saying there were two versions of the APF circuit in the FT-1000D over the years. It has been the consensus of owners that the earlier version was superior to the later version. The APF in both the K3 and KX3 is excellent, in my opinion. 73, Kent K9ZTV K3/KX3 s.n. 21 On 2/5/2016 10:03 AM, Stephen Prior wrote: I've seen it written that it helps to offset the IF slightly, although to be honest I have never myself got the APF to work to my satisfaction. Oddly, and I communicated with Wayne about this at the time, the first beta (I think) implementation of it was stunning, but a later release lost it for me. Wayne told me there had been no change in code, but I have never understood that. __ 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
Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3
I suspect that when the K3 APF was first engineered, the Yaesu FT-1000D APF (original hi-Q version) was used as the model because many prominent dx'ers/topbanders always raved about it. 73, Barry N1EU On Fri, Feb 5, 2016 at 12:37 PM, Scott via Elecraft < elecraft@mailman.qth.net> wrote: > > In the last month of listening to really weak signals here in 9 land I've > found it helpful but not radical. > > Just for fun I tried tuning some of the same VP8SGI signals on a Drake > 2B/2BQ and found adding the 2BQ in the mix more user friendly and making a > bigger difference, but hey, the 2B was starting from a worse spot. > > Still it would be nice if the APF was user adjustable like the 2BQ or the > old outbaord audio filters, peak magnitude, and maybe even frequency, > within > a selected passband. > > Not sure why Wayne picked only 3 db - I'd like it to be user adustable to > try a bit more peak if conditions permit. > > If APF is user adjustable in that way and I missed it somebody please > point out the page numberor if the experiment's been done and it's not > workable would like to know that too. > > 73 Scott ka9p > > > > In a message dated 2/5/2016 11:08:53 A.M. Central Standard Time, > ho13d...@gmail.com writes: > > > > one must also discover the > > artful use of the RF Gain control as well > > Adjustment of the RF gain control is not mentioned in Wayne's note on > using APF. > > When I tried it here, the RF gain might have made some small > difference but it still did not allow un-copyable signals to be > copied. When testing APF I have made all adjustments the I thought > might affect signal quality. IIRC correctly I also tinkered with the > AGC parameters. But the APF never produced results any better than > simply narrowing the filters. Usually the regular narrow filters > worked better. I know I had not switched APF on for months. I did > switch it on to recheck before sending my note. But the noise is not > currently high enough to give it a good test. > > I have found, in general, that careful adjustment of the RF gain > control can be useful. This applies to all receivers I have tried it on. > > I'm wondering if the difference is in the type of noise. I have mostly > tried APF at times of high lightning activity. I think we in the SE > get more of that than other parts of the country. The higher noise > level means more weak signals. You need all the help you can get. But > that noise differs from the usual band noise. > > And it may depend on each individual's hearing. > > I have always puzzled over why some rave about how great APF is while > for myself, and obviously others, it is of no help at all. > > 73 de dave > ab9ca/4 > > > > On 2/5/16 10:13 AM, Bob McGraw K4TAX wrote: > > While I find the APF works really nice, one must also discover the > > artful use of the RF Gain control as well. Most hams seem to use > > excessive RF Gain which will force noise through the filter and all of > > those undesirable artifacts will be heard. If in doubt, reduce the RF > > Gain. > > > > Using this technique, I can tune the band with the APF engaged, > > adjusting the RF Gain a bit, and actually hear signals with this > > configuration which without the APC no signal could be heard. I view > > this gives one the ability to actually "dig signals out of the noise". > > > > 73 > > Bob, K4TAX > > > > On 2/5/2016 9:56 AM, dave wrote: > >> > >> I'd agree. My experience with APF is that it will indeed pop a > >> signal that is already copyable, if a bit weak, out of the noise. > >> Makes for easier copy. However the ringing is so bad on a really > >> weak signal that it is of no help. I guess it depends on what you > >> view as 'weak' and your noise level. I was hoping it would make > >> previously un-copyable signals copyable, but that does not happen. > >> Instead it improves the copyability of weak but already copyable > >> signals. > >> > >> I find that simply narrowing the filters to 50, 100, or 150 Hz will > >> give essentially identical results as using the APF and is much > >> easier to do. > >> > >> As for the super critical tuning, I do not find it to be all that > >> critical. The signal can be improved somewhat by going to the 'fine' > >> tuning, but it makes only a small difference. 10 Hz steps are OK and > >> much quicker. The APF has a BW of about 30 Hz so tuning cannot be > >> all that critical. +/- 5 Hz out of 30 is not that big of a deal. > >> > >> This has been one of my biggest disappointments with the K3. After > >> reading all the hype about APF I was hoping for a real improvement. > >> But does not happen. OTOH, the narrow filters of the K3 are > >> outstanding. > >> > >> 73 de dave > >> ab9ca/4 > >> > >> > >> > >> On 2/5/16 8:53 AM, David Kuechenmeister 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
Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3
In the last month of listening to really weak signals here in 9 land I've found it helpful but not radical. Just for fun I tried tuning some of the same VP8SGI signals on a Drake 2B/2BQ and found adding the 2BQ in the mix more user friendly and making a bigger difference, but hey, the 2B was starting from a worse spot. Still it would be nice if the APF was user adjustable like the 2BQ or the old outbaord audio filters, peak magnitude, and maybe even frequency, within a selected passband. Not sure why Wayne picked only 3 db - I'd like it to be user adustable to try a bit more peak if conditions permit. If APF is user adjustable in that way and I missed it somebody please point out the page numberor if the experiment's been done and it's not workable would like to know that too. 73 Scott ka9p In a message dated 2/5/2016 11:08:53 A.M. Central Standard Time, ho13d...@gmail.com writes: > one must also discover the > artful use of the RF Gain control as well Adjustment of the RF gain control is not mentioned in Wayne's note on using APF. When I tried it here, the RF gain might have made some small difference but it still did not allow un-copyable signals to be copied. When testing APF I have made all adjustments the I thought might affect signal quality. IIRC correctly I also tinkered with the AGC parameters. But the APF never produced results any better than simply narrowing the filters. Usually the regular narrow filters worked better. I know I had not switched APF on for months. I did switch it on to recheck before sending my note. But the noise is not currently high enough to give it a good test. I have found, in general, that careful adjustment of the RF gain control can be useful. This applies to all receivers I have tried it on. I'm wondering if the difference is in the type of noise. I have mostly tried APF at times of high lightning activity. I think we in the SE get more of that than other parts of the country. The higher noise level means more weak signals. You need all the help you can get. But that noise differs from the usual band noise. And it may depend on each individual's hearing. I have always puzzled over why some rave about how great APF is while for myself, and obviously others, it is of no help at all. 73 de dave ab9ca/4 On 2/5/16 10:13 AM, Bob McGraw K4TAX wrote: > While I find the APF works really nice, one must also discover the > artful use of the RF Gain control as well. Most hams seem to use > excessive RF Gain which will force noise through the filter and all of > those undesirable artifacts will be heard. If in doubt, reduce the RF > Gain. > > Using this technique, I can tune the band with the APF engaged, > adjusting the RF Gain a bit, and actually hear signals with this > configuration which without the APC no signal could be heard. I view > this gives one the ability to actually "dig signals out of the noise". > > 73 > Bob, K4TAX > > On 2/5/2016 9:56 AM, dave wrote: >> >> I'd agree. My experience with APF is that it will indeed pop a >> signal that is already copyable, if a bit weak, out of the noise. >> Makes for easier copy. However the ringing is so bad on a really >> weak signal that it is of no help. I guess it depends on what you >> view as 'weak' and your noise level. I was hoping it would make >> previously un-copyable signals copyable, but that does not happen. >> Instead it improves the copyability of weak but already copyable >> signals. >> >> I find that simply narrowing the filters to 50, 100, or 150 Hz will >> give essentially identical results as using the APF and is much >> easier to do. >> >> As for the super critical tuning, I do not find it to be all that >> critical. The signal can be improved somewhat by going to the 'fine' >> tuning, but it makes only a small difference. 10 Hz steps are OK and >> much quicker. The APF has a BW of about 30 Hz so tuning cannot be >> all that critical. +/- 5 Hz out of 30 is not that big of a deal. >> >> This has been one of my biggest disappointments with the K3. After >> reading all the hype about APF I was hoping for a real improvement. >> But does not happen. OTOH, the narrow filters of the K3 are >> outstanding. >> >> 73 de dave >> ab9ca/4 >> >> >> >> On 2/5/16 8:53 AM, David Kuechenmeister 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 >>> wrote: >>> >>> >>> Hi all, >>> >>> This morni
Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3
Lightning has dramatic effect on the AGC system of many to most receivers. Rob Sherwood has had a lot to say about this. Elecraft has taken steps to minimize the effect. Yes different types of noise clearly have different characteristics and thus the reason for suggesting reducing the RF Gain, it reduces the noise. Fortunately this time of year in our location in TN the noise is quite low, unless a line of thunder storms is located within 500 or so miles. Hear this morning no thunder storms close by, the neighborhood is reasonably quiet, and the noise on 40M is about -103 dBm. With the APF a signal at -113 dBm can be easily copied, yet without the APF nothing but noise is heard. My technique is to observe the S meter, no signal, RF Gain at max for the given band and antenna. Then with the antenna disconnected, actually by a switch, I adjust the RF Gain until the S meter indicates the same value as the noise coming in on the antenna. Then switch the antenna back to the receiver. Also the AUTO SPOT feature is a big aid to optimum tuning. The result is signal present and no noise. 73 Bob, K4TAX On 2/5/2016 10:49 AM, dave wrote: one must also discover the artful use of the RF Gain control as well Adjustment of the RF gain control is not mentioned in Wayne's note on using APF. When I tried it here, the RF gain might have made some small difference but it still did not allow un-copyable signals to be copied. When testing APF I have made all adjustments the I thought might affect signal quality. IIRC correctly I also tinkered with the AGC parameters. But the APF never produced results any better than simply narrowing the filters. Usually the regular narrow filters worked better. I know I had not switched APF on for months. I did switch it on to recheck before sending my note. But the noise is not currently high enough to give it a good test. I have found, in general, that careful adjustment of the RF gain control can be useful. This applies to all receivers I have tried it on. I'm wondering if the difference is in the type of noise. I have mostly tried APF at times of high lightning activity. I think we in the SE get more of that than other parts of the country. The higher noise level means more weak signals. You need all the help you can get. But that noise differs from the usual band noise. And it may depend on each individual's hearing. I have always puzzled over why some rave about how great APF is while for myself, and obviously others, it is of no help at all. 73 de dave ab9ca/4 __ 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
Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3
The technique I'm using with the APF also involves NR like so: On an uncrowded band, set the DSP BW to 700 to 1000 Hz. If you have a roofing filter in that range stay within it. Turn on NR set to mF5-3 or there about. The wide BW helps the NR work well. The "mix" mode lets a little unprocessed signal+noise through. This is a good weak signal search mode. When you find a signal you want to copy, turn on APF and peak it in the filter. Fine tuning helps. There is little ringing because NR has reduced the noise amplitude. You can decrease the DSP BW a little but the NR is more effective with uncorrelated noise. This technique has gotten me many pelts in the QRP Fox Hunts. 73, Brian, K0DTJ __ 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
Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3
one must also discover the artful use of the RF Gain control as well Adjustment of the RF gain control is not mentioned in Wayne's note on using APF. When I tried it here, the RF gain might have made some small difference but it still did not allow un-copyable signals to be copied. When testing APF I have made all adjustments the I thought might affect signal quality. IIRC correctly I also tinkered with the AGC parameters. But the APF never produced results any better than simply narrowing the filters. Usually the regular narrow filters worked better. I know I had not switched APF on for months. I did switch it on to recheck before sending my note. But the noise is not currently high enough to give it a good test. I have found, in general, that careful adjustment of the RF gain control can be useful. This applies to all receivers I have tried it on. I'm wondering if the difference is in the type of noise. I have mostly tried APF at times of high lightning activity. I think we in the SE get more of that than other parts of the country. The higher noise level means more weak signals. You need all the help you can get. But that noise differs from the usual band noise. And it may depend on each individual's hearing. I have always puzzled over why some rave about how great APF is while for myself, and obviously others, it is of no help at all. 73 de dave ab9ca/4 On 2/5/16 10:13 AM, Bob McGraw K4TAX wrote: While I find the APF works really nice, one must also discover the artful use of the RF Gain control as well. Most hams seem to use excessive RF Gain which will force noise through the filter and all of those undesirable artifacts will be heard. If in doubt, reduce the RF Gain. Using this technique, I can tune the band with the APF engaged, adjusting the RF Gain a bit, and actually hear signals with this configuration which without the APC no signal could be heard. I view this gives one the ability to actually "dig signals out of the noise". 73 Bob, K4TAX On 2/5/2016 9:56 AM, dave wrote: I'd agree. My experience with APF is that it will indeed pop a signal that is already copyable, if a bit weak, out of the noise. Makes for easier copy. However the ringing is so bad on a really weak signal that it is of no help. I guess it depends on what you view as 'weak' and your noise level. I was hoping it would make previously un-copyable signals copyable, but that does not happen. Instead it improves the copyability of weak but already copyable signals. I find that simply narrowing the filters to 50, 100, or 150 Hz will give essentially identical results as using the APF and is much easier to do. As for the super critical tuning, I do not find it to be all that critical. The signal can be improved somewhat by going to the 'fine' tuning, but it makes only a small difference. 10 Hz steps are OK and much quicker. The APF has a BW of about 30 Hz so tuning cannot be all that critical. +/- 5 Hz out of 30 is not that big of a deal. This has been one of my biggest disappointments with the K3. After reading all the hype about APF I was hoping for a real improvement. But does not happen. OTOH, the narrow filters of the K3 are outstanding. 73 de dave ab9ca/4 On 2/5/16 8:53 AM, David Kuechenmeister 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 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 selecte
Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3
While I find the APF works really nice, one must also discover the artful use of the RF Gain control as well. Most hams seem to use excessive RF Gain which will force noise through the filter and all of those undesirable artifacts will be heard. If in doubt, reduce the RF Gain. Using this technique, I can tune the band with the APF engaged, adjusting the RF Gain a bit, and actually hear signals with this configuration which without the APC no signal could be heard. I view this gives one the ability to actually "dig signals out of the noise". 73 Bob, K4TAX On 2/5/2016 9:56 AM, dave wrote: I'd agree. My experience with APF is that it will indeed pop a signal that is already copyable, if a bit weak, out of the noise. Makes for easier copy. However the ringing is so bad on a really weak signal that it is of no help. I guess it depends on what you view as 'weak' and your noise level. I was hoping it would make previously un-copyable signals copyable, but that does not happen. Instead it improves the copyability of weak but already copyable signals. I find that simply narrowing the filters to 50, 100, or 150 Hz will give essentially identical results as using the APF and is much easier to do. As for the super critical tuning, I do not find it to be all that critical. The signal can be improved somewhat by going to the 'fine' tuning, but it makes only a small difference. 10 Hz steps are OK and much quicker. The APF has a BW of about 30 Hz so tuning cannot be all that critical. +/- 5 Hz out of 30 is not that big of a deal. This has been one of my biggest disappointments with the K3. After reading all the hype about APF I was hoping for a real improvement. But does not happen. OTOH, the narrow filters of the K3 are outstanding. 73 de dave ab9ca/4 On 2/5/16 8:53 AM, David Kuechenmeister 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 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 n...@bellsouth.net __ 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 ho13d...@gmail.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 Message delivered to rmcg...@blomand.net __ 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 h
Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3
I went from a TenTec Orion to my K3 ( whose box I opened almost the very day the K3S was announced which is total BS) and I really mis the SAF feature in the Orion. The APF in my K3 doesn't touch it. W5SUM Sent from Ronnie's IPhone > On Feb 5, 2016, at 09:56, dave wrote: > > > I'd agree. My experience with APF is that it will indeed pop a signal that is > already copyable, if a bit weak, out of the noise. Makes for easier copy. > However the ringing is so bad on a really weak signal that it is of no help. > I guess it depends on what you view as 'weak' and your noise level. I was > hoping it would make previously un-copyable signals copyable, but that does > not happen. Instead it improves the copyability of weak but already copyable > signals. > > I find that simply narrowing the filters to 50, 100, or 150 Hz will give > essentially identical results as using the APF and is much easier to do. > > As for the super critical tuning, I do not find it to be all that critical. > The signal can be improved somewhat by going to the 'fine' tuning, but it > makes only a small difference. 10 Hz steps are OK and much quicker. The APF > has a BW of about 30 Hz so tuning cannot be all that critical. +/- 5 Hz out > of 30 is not that big of a deal. > > This has been one of my biggest disappointments with the K3. After reading > all the hype about APF I was hoping for a real improvement. But does not > happen. OTOH, the narrow filters of the K3 are outstanding. > > 73 de dave > ab9ca/4 > > > >> On 2/5/16 8:53 AM, David Kuechenmeister 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 >> 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 >> n...@bellsouth.net >> >> >> >> __ >> 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 >> ho13d...@gmail.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 > Message delivered to w5...@comcast.net __ 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
Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3
I've seen it written that it helps to offset the IF slightly, although to be honest I have never myself got the APF to work to my satisfaction. Oddly, and I communicated with Wayne about this at the time, the first beta (I think) implementation of it was stunning, but a later release lost it for me. Wayne told me there had been no change in code, but I have never understood that. With my XYL away in London for the weekend, I might devote some more time to it :-) 73 Stephen G4SJP On 5 February 2016 at 15:27, David Kuechenmeister 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 > 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 > 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 n...@bellsouth.net > > > > > > > > __ > > 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 n1eu.ba...@gmail.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 > Message delivered to n...@bellsouth.net > > > > __ > 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 eastbrantw...@gmail.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 Message delivered to arch...@mail-archive.com
Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3
I'd agree. My experience with APF is that it will indeed pop a signal that is already copyable, if a bit weak, out of the noise. Makes for easier copy. However the ringing is so bad on a really weak signal that it is of no help. I guess it depends on what you view as 'weak' and your noise level. I was hoping it would make previously un-copyable signals copyable, but that does not happen. Instead it improves the copyability of weak but already copyable signals. I find that simply narrowing the filters to 50, 100, or 150 Hz will give essentially identical results as using the APF and is much easier to do. As for the super critical tuning, I do not find it to be all that critical. The signal can be improved somewhat by going to the 'fine' tuning, but it makes only a small difference. 10 Hz steps are OK and much quicker. The APF has a BW of about 30 Hz so tuning cannot be all that critical. +/- 5 Hz out of 30 is not that big of a deal. This has been one of my biggest disappointments with the K3. After reading all the hype about APF I was hoping for a real improvement. But does not happen. OTOH, the narrow filters of the K3 are outstanding. 73 de dave ab9ca/4 On 2/5/16 8:53 AM, David Kuechenmeister 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 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 n...@bellsouth.net __ 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 ho13d...@gmail.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 Message delivered to arch...@mail-archive.com
Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3
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 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 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 > 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 n...@bellsouth.net > > > > __ > 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 n1eu.ba...@gmail.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 Message delivered to n...@bellsouth.net __ 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
Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3
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 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 > 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 n...@bellsouth.net > > > > __ > 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 n1eu.ba...@gmail.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 Message delivered to arch...@mail-archive.com
Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3
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 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 n...@bellsouth.net __ 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
Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3
Dang.tnx for the reminder about APF, Wayne --- still getting "comfortable" with my KX3 so forgot about its value while engaged in self-flagellation i.e., operating in the CQ 160 contest last weekend. 72 de Jim Rodenkirch K9JWV -- View this message in context: http://elecraft.365791.n2.nabble.com/APF-audio-peaking-filter-on-the-K3-K3S-KX3-tp7613416p7613419.html Sent from the Elecraft 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 Message delivered to arch...@mail-archive.com
Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3
As a new K3S owner {since last August}, I agree. The APF seems to lift
signals out of the noise when otherwise, one would not know they are
present. I've used it successfully many times on weak signal QSO's.
Thanks for designing a great radio for the ham market.
73
Bob, K4TAX
K3S, s/n 10163
On 2/2/2016 8:34 AM, Wayne Burdick 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 rmcg...@blomand.net
__
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
[Elecraft] APF (audio peaking filter) on the K3/K3S/KX3
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
[Elecraft] APF
Whatever happened to the plan to provide adjustable or stepped values of selectivity for the APF function? I rigged up a kluge consisting of an old Autek QF-1A but would much rather have it's function built-in. 73 Roger __ 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
[Elecraft] APF filter band width adjustment
*/I agree I always liked to adjust my ft1000d APF a bit off center as well. Regards Art ka9zap /* On 2/14/2015 9:42 PM, Guy Olinger K2AV wrote: One thing I like about it is that a "hold" on the SUB button now puts you back in diversity immediately. Quick way to get it back when a split spot has turned it off. I still would like to see variable APF to let me set it a little farther off ringing, or put a wider peak on some situations. Use the RIT control to control APF bandwidth if RIT and XIT are off. That other fast tune thing with the RIT knob winds up happening when I forget it's on. Now I can't find the menu entry to turn it off. 73, Guy K2AV __ 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
Re: [Elecraft] APF
Thanks, Don. My choice of 700-1000 Hz is more for the NR than for the APF. The idea is to get the noise going into the NR routine as uncorrelated as practical. The knee of that curve seems to be around 700 Hz. Any lower and the NR doesn't work as well. It's a bit subjective. Also using the "mix" mode of the NR is key because it gives the APF some "pure" signal to work on. 73, Brian, K0DTJ __ 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
Re: [Elecraft] APF
Brian, Yes, using APF with a wider bandwidth helps, but a width more narrow than 700 Hz should be usable - 400 Hz and more narrow may be "iffy". FINE tuning with APF turned on is a necessity. 73, Don W3FPR On 3/16/2014 8:44 PM, Brian Hunt wrote: My "formula" for tuning very weak signals - almost can't see them on the P3 - is as follows: - Set the WIDTH to 700 Hz to 1 KHz QRM permitting. - Turn on NR and set to 5m3 or there about. - Turn on APF and tune for best audio. Setting the rate to FINE sometimes helps. This almost completely eliminates noise ringing the filter although the signal does ring a little. YMMV. 73, Brian, K0DTJ __ 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 This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] APF
My "formula" for tuning very weak signals - almost can't see them on the P3 - is as follows: - Set the WIDTH to 700 Hz to 1 KHz QRM permitting. - Turn on NR and set to 5m3 or there about. - Turn on APF and tune for best audio. Setting the rate to FINE sometimes helps. This almost completely eliminates noise ringing the filter although the signal does ring a little. YMMV. 73, Brian, K0DTJ __ 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
Re: [Elecraft] APF
Todd, I am not going to "weigh in" on anything you said. In the case of APF, the instructions by your very Zen instructor may the best appropriate answer. Before you need to use it, give it a try on some weak signals and play with the width and shift controls until you get a feel for it. It will not seem to work very well on signals that can be copied without the APF, so concentrate on the weak ones. 73, Don W3FPR On 3/16/2014 6:33 PM, todd ruby wrote: I have received 2 inquiries about how to use the APF. Well, I’ll put it to you this way. I used to be a photographer and used a 5X7 view camera. The image on the viewing glass was upside down, both the front (lens board) and rear (view glass) board swiveled from side to side and up and down. It was very frustrating for a 20 year old perfectionist to figure out how to manuever either of the boards together or individually to get the desired image. My teacher was very Zen about it. He said “F….k with it until it looks right. Basically this is what I did to pull in Zorro in Myanmar who was a hair above the noise level. Every time I used the APF previously I got too much ringing and couldn’t hear the signal I wanted to zero in on. Truly, today it was a matter of opening up the width and lowering the shift to get rid of the ring, then playing with the two until I could hear his signal at its best. Switching back to the regular roofing filter (400 hz) didn’t cut it. The APF isolated Zorro enough to copy him Q5. So my answer and my future technique will rely on messing with both the width and the shift until you can get rid of the ring and eke out the signal. I am sure Don Wilhelm, Wayne and Jim Brown will weigh in on me being overly simplistic but it worked for me and we are both in each others log! __ 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] APF
I have received 2 inquiries about how to use the APF. Well, I’ll put it to you this way. I used to be a photographer and used a 5X7 view camera. The image on the viewing glass was upside down, both the front (lens board) and rear (view glass) board swiveled from side to side and up and down. It was very frustrating for a 20 year old perfectionist to figure out how to manuever either of the boards together or individually to get the desired image. My teacher was very Zen about it. He said “F….k with it until it looks right. Basically this is what I did to pull in Zorro in Myanmar who was a hair above the noise level. Every time I used the APF previously I got too much ringing and couldn’t hear the signal I wanted to zero in on. Truly, today it was a matter of opening up the width and lowering the shift to get rid of the ring, then playing with the two until I could hear his signal at its best. Switching back to the regular roofing filter (400 hz) didn’t cut it. The APF isolated Zorro enough to copy him Q5. So my answer and my future technique will rely on messing with both the width and the shift until you can get rid of the ring and eke out the signal. I am sure Don Wilhelm, Wayne and Jim Brown will weigh in on me being overly simplistic but it worked for me and we are both in each others log! 73 todd WB2ZAB __ 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] APF
Dear List Readers Eureka moment! I finally figured out how to use the APF effectively, and it really does work on digging out weak sigs. XZ1Z was virtually indecipherable until I started messing with the APF. All of a sudden, I heard him Q5 (enough) to hear him come back to me distinctly. Thank you Elecraft and thank you Zorro! 73 todd WB2ZAB __ 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
Re: [Elecraft] APF
Hi all, and Sam; > > >Message: 7 >Date: Sat, 07 Dec 2013 19:38:20 -0600 >From: Sam Morgan >To: "elecraft@mailman.qth.net" >Subject: Re: [Elecraft] APF >Message-ID: <52a3cd8c.2090...@gmail.com> >Content-Type: text/plain; charset=ISO-8859-1; format=flowed > >1st of all let me be clear, I was merely quoting from my notes that I >had copied from a post (or web site?) that Dusty K3WC wrote > >that said >yes it was the Shift knob Dusty was speaking of >calling it the Shift Fc (frequency) knob > >when I turn mine it says (in the VFO B window) >APF *0.48 (my pitch is set for 480hz) >so I have to turn the Shift knob until I see it say APF 0.46 >meaning it's at 460hz or 20hz below my default pitch of 480hz >Sam, you are doing fine in explaining, Thanks! I searched around on my hard >drive and found the piece that Dusty wrote--I also had downloaded it and saved >it but I didn't mark where I got it, just his call. The problem WAS, that using the shift in APF wouldn't move anything (only showed FC *0.50 in the VFO B window). I went to Fred's book and found that Dual PB needed to be set to APF in the CONFIG (mine some how got set to "nor"). Putting that right has completely changed things! I had about given up on using APF but now it works as it should and I feel good! Thanks for helping me straighten that out, Sam and Bill, W4ZV. Now I can get back to trying to get a valid contact with T32RC--I have worked them 3 times on CW and they have never logged my call correctly even though I thought they had it. Thanks all--as always, good help here! 73 and good DX, Scott AA0AA; XE1/AA0AA __ 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
Re: [Elecraft] APF
I agree with Bill. There's no need to fiddle with the RIT control. I think Dusty's original suggestion implies that he found the APF to be more effective at a slightly lower frequency (20Hz lower) than his nominal CW pitch setting. This may be true but it can be more easily accomplished by tuning the signal a bit lower in frequency with the main VFO. Then just tweak the APF center frequency with the SHIFT knob. Dusty's suggestion may appeal to some because it doesn't shift your transmit frequency 20Hz off of zero beat. In the grand scheme, however, 20Hz off of zero beat is hardly noticeable. The important thing here is to play with the APF and learn how to use it. You don't have to wait for weak signals. You can experiment with medium strength signals. Then once you get the hang of it you'll be good to go when trying to pull out a weak one. But don't expect the APF to pull them all in. The APF has its limitations. 73, Mike K2MK Bill W4ZV wrote > IMHO K3WC's APF suggestion is WAY TOO COMPLICATED. I use APF virtually > all the time and never use RIT, SHIFT, etc. Just HOLD DUAL PB to actuate > APF and use the VFO to zero beat. COARSE (10 Hz) VFO steps is usually > close enough but you can switch to FINE (1 Hz) if necessary for ultra weak > signals. I also strongly endorse N6KR's suggestion below: > > "I suggest setting the passband width to about 250-300 Hz when using APF." > > This is extremely important since bandwidths too narrow will introduce > additional ringing to the APF which already borders on ringing. I > actually use a 200 Hz XFIL but set to actuate at DSP 400 Hz. With WIDTH > set to 400 Hz, the signal first goes through the relatively broad (4.0 > shape factor) 200 Hz XFIL, then a 400 Hz DSP and finally the narrow APF. > This makes the cascaded XFIL/DSP look more like 250 Hz, reduces ringing, > still allows you to hear off-frequency callers (although attenuated) and > helps your ears discriminate weak signals from noise by providing a wider > background sample of noise. > > 73, Bill W4ZV > > Scott Monks wrote >> Sam; >> Your explanation is really good Sam, but it seems that something >> doesn't follow for me. >> >> cut... >> >>>Turn on the RIT control (tap the RIT button). Next, lower the RIT >>>frequency -20 Hz. (You must have CONFIG:PB CTRL in the config menu set >>>to .01 to move in 10 Hz steps). If your pitch is set to 500 Hz, then the >>>tone of the CW should now be 480 Hz. Next, turn on the APF by HOLDING >>>the DUAL PB button. Adjust the APF using the SHIFT Fc Knob (now APF >>>control). Move the APF down -20 Hz to match the CW signal. Once you have >>>the signal in the center of the new 480 Hz tone you should hear that the >>>CW signal pops up about 5 or 6 dB >>>Ok, I did this, first setting my pitch at 500 Hz, which actually even cut out some ringing! I got the station centered, etc., turned RIT down -20, activated APF, but then the problem began. >> >> I am not sure what the "SHIFT Fc Knob" is--if it is just the regular >> "Shift-Lo" knob then this doesn't do anything for me when I turn it. Is >> this the right knob? Do I need something turned on in CONFIG for it to >> work? >> >> >> I have had my K3 a little more than 1yr., and I sort of remember that >> MAYBE I could move the passband once at first, but I my be remembering >> bad! >> >> Thanks for the help. 73 >> >> >> Scott >> >> AA0AA; XE1/AA0AA -- View this message in context: http://elecraft.365791.n2.nabble.com/APF-tp7581300p7581515.html Sent from the Elecraft 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
Re: [Elecraft] APF
I too often use APF on both the K3 and KX3. I prefer tuning APF with 1 Hz steps. The KX3 enables 1 HZ steps when APF is enabled. I miss that feature with the K3. A new feature request; when in SPLIT and VFO A at 1 Hz, leave VFO B at 10 Hz. John KN5L On 12/08/2013 04:48 AM, Bill W4ZV wrote: > I use APF virtually all > the time and never use RIT, SHIFT, etc. Just HOLD DUAL PB to actuate APF > and use the VFO to zero beat. COARSE (10 Hz) VFO steps is usually close > enough but you can switch to FINE (1 Hz) if necessary for ultra weak > signals. __ 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
Re: [Elecraft] APF
IMHO K3WC's APF suggestion is WAY TOO COMPLICATED. I use APF virtually all the time and never use RIT, SHIFT, etc. Just HOLD DUAL PB to actuate APF and use the VFO to zero beat. COARSE (10 Hz) VFO steps is usually close enough but you can switch to FINE (1 Hz) if necessary for ultra weak signals. I also strongly endorse N6KR's suggestion below: "I suggest setting the passband width to about 250-300 Hz when using APF." This is extremely important since bandwidths too narrow will introduce additional ringing to the APF which already borders on ringing. I actually use a 200 Hz XFIL but set to actuate at DSP 400 Hz. With WIDTH set to 400 Hz, the signal first goes through the relatively broad (4.0 shape factor) 200 Hz XFIL, then a 400 Hz DSP and finally the narrow APF. This makes the cascaded XFIL/DSP look more like 250 Hz, reduces ringing, still allows you to hear off-frequency callers (although attenuated) and helps your ears discriminate weak signals from noise by providing a wider background sample of noise. 73, Bill W4ZV Scott Monks wrote > Sam; > Your explanation is really good Sam, but it seems that something > doesn't follow for me. > > cut... > >>Turn on the RIT control (tap the RIT button). Next, lower the RIT >>frequency -20 Hz. (You must have CONFIG:PB CTRL in the config menu set >>to .01 to move in 10 Hz steps). If your pitch is set to 500 Hz, then the >>tone of the CW should now be 480 Hz. Next, turn on the APF by HOLDING >>the DUAL PB button. Adjust the APF using the SHIFT Fc Knob (now APF >>control). Move the APF down -20 Hz to match the CW signal. Once you have >>the signal in the center of the new 480 Hz tone you should hear that the >>CW signal pops up about 5 or 6 dB >>Ok, I did this, first setting my pitch at 500 Hz, which actually even cut out some ringing! I got the station centered, etc., turned RIT down -20, activated APF, but then the problem began. > > I am not sure what the "SHIFT Fc Knob" is--if it is just the regular > "Shift-Lo" knob then this doesn't do anything for me when I turn it. Is > this the right knob? Do I need something turned on in CONFIG for it to > work? > > > I have had my K3 a little more than 1yr., and I sort of remember that > MAYBE I could move the passband once at first, but I my be remembering > bad! > > Thanks for the help. 73 > > > Scott > > AA0AA; XE1/AA0AA > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto: > Elecraft@.qth > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html -- View this message in context: http://elecraft.365791.n2.nabble.com/APF-tp7581300p7581511.html Sent from the Elecraft 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
Re: [Elecraft] APF
1st of all let me be clear, I was merely quoting from my notes that I had copied from a post (or web site?) that Dusty K3WC wrote that said yes it was the Shift knob Dusty was speaking of calling it the Shift Fc (frequency) knob when I turn mine it says (in the VFO B window) APF *0.48 (my pitch is set for 480hz) so I have to turn the Shift knob until I see it say APF 0.46 meaning it's at 460hz or 20hz below my default pitch of 480hz sorry I'm not as good as Dusty at explaining these things sm On 12/7/2013 7:04 PM, Scott Monks wrote: Sam; Your explanation is really good Sam, but it seems that something doesn't follow for me. cut... Turn on the RIT control (tap the RIT button). Next, lower the RIT frequency -20 Hz. (You must have CONFIG:PB CTRL in the config menu set to .01 to move in 10 Hz steps). If your pitch is set to 500 Hz, then the tone of the CW should now be 480 Hz. Next, turn on the APF by HOLDING the DUAL PB button. Adjust the APF using the SHIFT Fc Knob (now APF control). Move the APF down -20 Hz to match the CW signal. Once you have the signal in the center of the new 480 Hz tone you should hear that the CW signal pops up about 5 or 6 dB Ok, I did this, first setting my pitch at 500 Hz, which actually even cut out some ringing! I got the station centered, etc., turned RIT down -20, activated APF, but then the problem began. I am not sure what the "SHIFT Fc Knob" is--if it is just the regular "Shift-Lo" knob then this doesn't do anything for me when I turn it. Is this the right knob? Do I need something turned on in CONFIG for it to work? I have had my K3 a little more than 1yr., and I sort of remember that MAYBE I could move the passband once at first, but I my be remembering bad! Thanks for the help. 73 Scott AA0AA; XE1/AA0AA -- GB & 73 K5OAI Sam Morgan __ 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
Re: [Elecraft] APF
Sam; Your explanation is really good Sam, but it seems that something doesn't follow for me. cut... >Turn on the RIT control (tap the RIT button). Next, lower the RIT >frequency -20 Hz. (You must have CONFIG:PB CTRL in the config menu set >to .01 to move in 10 Hz steps). If your pitch is set to 500 Hz, then the >tone of the CW should now be 480 Hz. Next, turn on the APF by HOLDING >the DUAL PB button. Adjust the APF using the SHIFT Fc Knob (now APF >control). Move the APF down -20 Hz to match the CW signal. Once you have >the signal in the center of the new 480 Hz tone you should hear that the >CW signal pops up about 5 or 6 dB >Ok, I did this, first setting my pitch at 500 Hz, which actually even cut out >some ringing! I got the station centered, etc., turned RIT down -20, >activated APF, but then the problem began. I am not sure what the "SHIFT Fc Knob" is--if it is just the regular "Shift-Lo" knob then this doesn't do anything for me when I turn it. Is this the right knob? Do I need something turned on in CONFIG for it to work? I have had my K3 a little more than 1yr., and I sort of remember that MAYBE I could move the passband once at first, but I my be remembering bad! Thanks for the help. 73 Scott AA0AA; XE1/AA0AA __ 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] APF
The subject line should read APF of course, sorry! Sam, thank you for the tips on APF. One remark though: "Switching between the two filters is as easy as HOLDING the SHIFT knob in." I suppose you mean the WIDTH knob... 73 Richard - HB9ANM __ 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
Re: [Elecraft] APF
one more fyi on the [XFIL/DUALPB] button when in RTTY, both AFSK A and FSK D, it's a Dual Passband Filter when in CW mode it acts like the single peak APF there's an image of the APF in use on N1EU site: http://n1eu.com/K3/K3_apf.htm On 11/30/2013 11:56 AM, Sam Morgan wrote: I'll copy and paste from my notes, hope it helps clear it up for you. sm APF on the K3 The APF is an easy tool to use. However, one of the main concerns people are talking about now is the fact that the filter seems to be a bit tight, and tends to ring. This, of course, is normal for an APF (IIR type filter), but not everyone wants to hear ringing on their CW signal when they use it. Others just can’t copy the CW signal when the ringing is at the same exact frequency as their CW tone. For this reason I have written this little tutorial on how to remove the ringing from your APF filter while still getting the most out of it. Let’s start by centering your SHIFT (before you turn on the APF) and make sure you see the * next to your PITCH/center IF frequency. Next, spot the CW signal in. i.e., hit the SPOT button when you’re trying to copy someone, or use the VFO to center the line on the CWT display. Now you can be sure that the CW station is in the center of your IF passband. Next, adjust the width setting to your liking. It almost doesn’t matter once the APF is on what you choose. However, what it will help with is blocking noise from the sides of the signal you’re listening to. This can be helpful if you have other stations that are very close to the CW signal you’re trying to peak. The lower you set your Width filter the more you will reject to the sides. Any signals (including noise) that are left over on the sides will be compounded into the center of your IF passband and cause more ringing noise. So I would suggest that you keep your WIDTH from 250 Hz to 100 Hz setting. You can play more with the WIDTH control once you have the APF on. Turn on the RIT control (tap the RIT button). Next, lower the RIT frequency -20 Hz. (You must have CONFIG:PB CTRL in the config menu set to .01 to move in 10 Hz steps). If your pitch is set to 500 Hz, then the tone of the CW should now be 480 Hz. Next, turn on the APF by HOLDING the DUAL PB button. Adjust the APF using the SHIFT Fc Knob (now APF control). Move the APF down -20 Hz to match the CW signal. Once you have the signal in the center of the new 480 Hz tone you should hear that the CW signal pops up about 5 or 6 dB. What you should also notice is that CW tone is now centered at a different frequency than your IF passband center. This also allows you to avoid peaking the ringing sounds that live in the center of your selected IF area. Your brain is now free to discriminate the two different tones instead of having to copy code at the same frequency as all the ringing noise. If and When the K3 has a variable Q adjustment you will then be able to avoid the ringing by opening up the tightness of the PEAK Filter and allowing a little more signal to pass. Of course you also compromise the “sharpness” of the current APF operation, but if you feel that you don’t need as much peaking on the signal then you will be able to control it a little more accurately. Having a Variable Q control would be best used on a signal that is ‘less’ weak than those hard to copy signals in the noise floor. Another great feature of the APF is being able to use it on either/or filter position I or II. If you like, you can set filter I for APF off, and filter II to APF on. Switching between the two filters is as easy as HOLDING the SHIFT knob in. Once you set either filter position with the APF on or off the K3 will remember how you have it set. Dusty K3WC Jun 26, 2012; 1:19pm K3/KX3 Operating Tip: APF (audio peaking filter) for weak-signal CW work Both the K3 and KX3 have an APF control (audio peaking filter). APF can be extremely effective when you're trying to copy weak CW signals buried in noise. Most DSP filters have very steep skirts; they're often referred to as "brick-wall" filters for this reason. This is the type of filtering associated with the WIDTH control (K3) or PBT control (KX3). In contrast, the APF is a filter with a very narrow peak (about 30 Hz at the -3 dB points) and very broad skirts. The narrow peak brings up the signal amplitude slightly, while the broad skirts prevent noise from being amplified and delayed in such a way as to dominate the signal. The APF function used in the K3 and KX3 is a modern DSP reinterpretation of the hardware APF circuit found on some legacy transceivers, which was very effective. On the KX3, the APF switch is labeled "APF" (tap), while on the K3, it's labeled "DUAL PB" (hold). The K3 actually provides two different special filter functions; use the DUAL PB menu entry to set up the switch for APF. When you turn on APF, the DSP graphic changes to remind you of the nature of APF, with its narrow peak and broad skirts.
Re: [Elecraft] APF
I'll copy and paste from my notes, hope it helps clear it up for you. sm APF on the K3 The APF is an easy tool to use. However, one of the main concerns people are talking about now is the fact that the filter seems to be a bit tight, and tends to ring. This, of course, is normal for an APF (IIR type filter), but not everyone wants to hear ringing on their CW signal when they use it. Others just can’t copy the CW signal when the ringing is at the same exact frequency as their CW tone. For this reason I have written this little tutorial on how to remove the ringing from your APF filter while still getting the most out of it. Let’s start by centering your SHIFT (before you turn on the APF) and make sure you see the * next to your PITCH/center IF frequency. Next, spot the CW signal in. i.e., hit the SPOT button when you’re trying to copy someone, or use the VFO to center the line on the CWT display. Now you can be sure that the CW station is in the center of your IF passband. Next, adjust the width setting to your liking. It almost doesn’t matter once the APF is on what you choose. However, what it will help with is blocking noise from the sides of the signal you’re listening to. This can be helpful if you have other stations that are very close to the CW signal you’re trying to peak. The lower you set your Width filter the more you will reject to the sides. Any signals (including noise) that are left over on the sides will be compounded into the center of your IF passband and cause more ringing noise. So I would suggest that you keep your WIDTH from 250 Hz to 100 Hz setting. You can play more with the WIDTH control once you have the APF on. Turn on the RIT control (tap the RIT button). Next, lower the RIT frequency -20 Hz. (You must have CONFIG:PB CTRL in the config menu set to .01 to move in 10 Hz steps). If your pitch is set to 500 Hz, then the tone of the CW should now be 480 Hz. Next, turn on the APF by HOLDING the DUAL PB button. Adjust the APF using the SHIFT Fc Knob (now APF control). Move the APF down -20 Hz to match the CW signal. Once you have the signal in the center of the new 480 Hz tone you should hear that the CW signal pops up about 5 or 6 dB. What you should also notice is that CW tone is now centered at a different frequency than your IF passband center. This also allows you to avoid peaking the ringing sounds that live in the center of your selected IF area. Your brain is now free to discriminate the two different tones instead of having to copy code at the same frequency as all the ringing noise. If and When the K3 has a variable Q adjustment you will then be able to avoid the ringing by opening up the tightness of the PEAK Filter and allowing a little more signal to pass. Of course you also compromise the “sharpness” of the current APF operation, but if you feel that you don’t need as much peaking on the signal then you will be able to control it a little more accurately. Having a Variable Q control would be best used on a signal that is ‘less’ weak than those hard to copy signals in the noise floor. Another great feature of the APF is being able to use it on either/or filter position I or II. If you like, you can set filter I for APF off, and filter II to APF on. Switching between the two filters is as easy as HOLDING the SHIFT knob in. Once you set either filter position with the APF on or off the K3 will remember how you have it set. Dusty K3WC Jun 26, 2012; 1:19pm K3/KX3 Operating Tip: APF (audio peaking filter) for weak-signal CW work Both the K3 and KX3 have an APF control (audio peaking filter). APF can be extremely effective when you're trying to copy weak CW signals buried in noise. Most DSP filters have very steep skirts; they're often referred to as "brick-wall" filters for this reason. This is the type of filtering associated with the WIDTH control (K3) or PBT control (KX3). In contrast, the APF is a filter with a very narrow peak (about 30 Hz at the -3 dB points) and very broad skirts. The narrow peak brings up the signal amplitude slightly, while the broad skirts prevent noise from being amplified and delayed in such a way as to dominate the signal. The APF function used in the K3 and KX3 is a modern DSP reinterpretation of the hardware APF circuit found on some legacy transceivers, which was very effective. On the KX3, the APF switch is labeled "APF" (tap), while on the K3, it's labeled "DUAL PB" (hold). The K3 actually provides two different special filter functions; use the DUAL PB menu entry to set up the switch for APF. When you turn on APF, the DSP graphic changes to remind you of the nature of APF, with its narrow peak and broad skirts. I suggest setting the passband width to about 250-300 Hz when using APF. The DSP graphic still shows an approximate representation of the width even with APF turned on. 73, Wayne N6KR On 11/30/2013
[Elecraft] APF
Can someone explain how to engage and use the Audio Peak Filter on the K3? thanks in advance todd WB2ZAB __ 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] APF and Tuning Speed
Hello all and Happy Thanksgiving: I am trying to create a macro to do the following: 1. Set radio to Fine tuning mode (1 hz increments) 2. Turn on APF Then with another push of a button 1. Turn off APF 2. Return radio to "regular tuning speed" (in my case 10 hz increments) I realize this would involve two separate macros. The problem I am having is if I use the command "swt49" and the radio happens to already be in the fine tuning mode, then it's switched to regular (with the APF enabled). I cannot see where a command exists to be able to set the tuning speed directly (VFO CTS is not what I want). Does anyone know if such a command exists or can anyone help solve my problem? I don't think I've seen this macro done before. Of course a menu select in APF would eliminate this problem! 73, Dan __ 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
Re: [Elecraft] APF question
Hello Mike, The APF, because of the high "Q" will naturally produce ringing with a strong signal. Just back down the RF Gain control until you can clearly hear the keying elements. However, I'd suggest that if the signal is that strong to begin with, you probably don't need to use the APF function. It is particularly effective though on very weak signals that are near the noise floor. 73, Dale WA8SRA On 11/11/2011 1:16 PM, Mike Weir wrote: > When using the APF function on my K3 I am getting a real tinny sound to the > point were it is difficult to understand the code. I was wondering if > settings were ok. > Here is what I do. > 1. Zero beat the CW signal with the spot feature and tuning is set to fine. > 2. The filter is set at either 400hz or 350hz > 3. The APF setting is a .60 I also adjust this setting to see if the audio > improves but it does not seem to. > 4. I do try to fine adjust the VFO (fine setting) for the signal to jump out. > All that happens is it gets more tinny. > Any suggestions? > Mike > VE3WDM > > __ > 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 This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] APF question
VE3WDM wrote: > > When using the APF function on my K3 I am getting a real tinny sound to > the point were it is difficult to understand the code. I was wondering if > settings were ok. > Here is what I do. > 1. Zero beat the CW signal with the spot feature and tuning is set to > fine. > 2. The filter is set at either 400hz or 350hz > 3. The APF setting is a .60 I also adjust this setting to see if the audio > improves but it does not seem to. > 4. I do try to fine adjust the VFO (fine setting) for the signal to jump > out. All that happens is it gets more tinny. > Any suggestions? > APF is not intended for signals much stronger than the noise floor. On stronger signals it sounds tinny because its 30 Hz filter is on the verge of ringing. If you can hear a CW signal Q5, you don't need or want APF. It's intended for the 339 and 449 signals buried in noise. It can bring these signals to Q5 but must be peaked carefully because the BW is so narrow. 73, Bill -- View this message in context: http://elecraft.365791.n2.nabble.com/APF-question-tp6986325p6986495.html Sent from the Elecraft 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
[Elecraft] APF question
When using the APF function on my K3 I am getting a real tinny sound to the point were it is difficult to understand the code. I was wondering if settings were ok. Here is what I do. 1. Zero beat the CW signal with the spot feature and tuning is set to fine. 2. The filter is set at either 400hz or 350hz 3. The APF setting is a .60 I also adjust this setting to see if the audio improves but it does not seem to. 4. I do try to fine adjust the VFO (fine setting) for the signal to jump out. All that happens is it gets more tinny. Any suggestions? Mike VE3WDM __ 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] APF - New things
Well even really old dogs can learn new stuff. Tuning around on 30m, with AFP enabled, something I have never done before -- I just forgot to turn it off, I found signals ... and worked one I did not hear with AFP turned off. I'm becoming convinced that my K3 [and K2 for that matter], are radios I need to experiment with. 73, Fred K6DGW Auburn CA __ 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
Re: [Elecraft] APF Macro
Dick, I just took a look at the macros in the K3 utility menu... WOW. I don't know how I missed it. Bill K9YEQ -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Dick Dievendorff Sent: Saturday, February 12, 2011 9:44 PM To: Ron D'Eau Claire Cc: Subject: Re: [Elecraft] APF Macro There are some samples in K3 Utility help, look for command macros in the index. I'm open to adding and annotating more samples. This isn't to discourage use of other repositories, however. 73 de Dick, K6KR On Feb 12, 2011, at 17:14, "Ron D'Eau Claire" wrote: > Age notwithstanding, many of us find messing with macros or other > 'programming' activities right up there in desirability with hauling > out the trash. > > Perhaps it would be possible for Elecraft to start building a macro library. > Even if a macro isn't exactly what you want, it's often a lot easier > to make a small change than to start from scratch. > > Ron AC7AC > > -Original Message- > From: elecraft-boun...@mailman.qth.net > [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of n...@aol.com > Sent: Saturday, February 12, 2011 2:56 PM > To: elecraft@mailman.qth.net > Subject: [Elecraft] APF Macro > > It is tough to get old and find most of your electronics know-how is > out of date- so much so that creating a macro from scratch seems beyond my ken. > > APF is a very useful function, and I use it along with RIT as the > fine tuning mechanism. How would one generate and execute as either > a macro, or > > PF1/PF2, to turn on and off a "APF and RIT activated" function? > > BIll Hartman > N6FB > __ > 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 > > 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 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 This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[Elecraft] APF Macros
I reported a macro for turning on APF, RIT, and FINE and shifting RIT down 20 Hz in a reflector message dated November 4, 2010. I also included a macro for clearing all these functions, since I could not seem to come up with a toggleable version. Since I wrote that, I revised my macro's to the following: APF SHF: IS ;SWH29;RT1;SWT53;RT0;RT1;RD;RD;SWT49;LK0; APF CLR: SWH29;SWT49;SWT53;RT0;IS ; These work for me (I have them assigned to PF1 and PF2, respectively. Perhaps someone else has a better set to report. I certainly like the idea of a shared library of macro's. 73, Chuck Guenther NI0C K2-10, K3, P3 N6FB wrote: "It is tough to get old and find most of your electronics know-how is out of date- so much so that creating a macro from scratch seems beyond my ken. APF is a very useful function, and I use it along with RIT as the fine tuning mechanism. How would one generate and execute as either a macro, or PF1/PF2, to turn on and off a "APF and RIT activated" function? BIll Hartman N6FB" __ 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
Re: [Elecraft] APF Macro
There are some samples in K3 Utility help, look for command macros in the index. I'm open to adding and annotating more samples. This isn't to discourage use of other repositories, however. 73 de Dick, K6KR On Feb 12, 2011, at 17:14, "Ron D'Eau Claire" wrote: > Age notwithstanding, many of us find messing with macros or other > 'programming' activities right up there in desirability with hauling out the > trash. > > Perhaps it would be possible for Elecraft to start building a macro library. > Even if a macro isn't exactly what you want, it's often a lot easier to make > a small change than to start from scratch. > > Ron AC7AC > > -Original Message- > From: elecraft-boun...@mailman.qth.net > [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of n...@aol.com > Sent: Saturday, February 12, 2011 2:56 PM > To: elecraft@mailman.qth.net > Subject: [Elecraft] APF Macro > > It is tough to get old and find most of your electronics know-how is out > of date- so much so that creating a macro from scratch seems beyond my ken. > > APF is a very useful function, and I use it along with RIT as the fine > tuning mechanism. How would one generate and execute as either a macro, or > > PF1/PF2, to turn on and off a "APF and RIT activated" function? > > BIll Hartman > N6FB > __ > 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 > > 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 This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] APF Macro
I could be all wet but I'm not sure you can, regardless of talent. The K3 command set is simply too limited. Ideally you would want to be able to go into the CONFIG menu and enable (make it available) the APF function. This isn't even straightforward doing it manually, because even though it is a CW only function, there shouldn't be (IMHO) a requirement for the mode to be in CW to enable the function, but you must. Second, when the APF is first turned on I believe that it should default to the PITCH frequency. But it doesn't and there is no way to make it so. The "IS 9000;" command will center the non-APF SHIFT to the PITCH frequency for a known starting point, but it doesn't work on APF. Third, the way APF is turned ON/OFF is via a "Hold" of a button and this a toggle function. This key hold can be commanded via a macro but there isn't a command to simply say, "Turn on (or off) the APF". So it seems to me that trying to assign a function to macro key assignment just moves the toggle requirement from one key to another. Hardly seems like progress. Wes N7WS --- On Sat, 2/12/11, n...@aol.com wrote: > From: n...@aol.com > Subject: [Elecraft] APF Macro > To: elecraft@mailman.qth.net > Date: Saturday, February 12, 2011, 3:55 PM > It is tough to get old and find most > of your electronics know-how is out > of date- so much so that creating a macro from scratch > seems beyond my ken. > > APF is a very useful function, and I use it along with RIT > as the fine > tuning mechanism. How would one generate and execute > as either a macro, or > PF1/PF2, to turn on and off a "APF and RIT activated" > function? > > BIll Hartman > N6FB > __ > 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 > The fish are biting. Get more visitors on your site using Yahoo! Search Marketing. http://searchmarketing.yahoo.com/arp/sponsoredsearch_v2.php __ 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
Re: [Elecraft] APF Macro
The help file of the K3 Utility program has lots of useful macros as well as the information on how to send them to the radio and assign them to radio buttons using the CONFIG menu. For anyone using DXLab's Commander rig control program, that program offers an alternative to macros in the K3. Commander's macros, called user-defined sequences, can be longer than those in the K3 Utility program. They don't use any of the buttons on the K3 either. You can even set up macros in DXLab's WinWarbler to activate the K3 voice memories if you have a K3DVR. They are also easy to share, with no typing or "programming" required. I have saved some of the ones I've created for my K3 on the DXLab Yahoo Group web site. They are simple text files that can be copied to your hard drive and assigned to an F-key or button on the Commander screen. I have Commander sequences to switch mics between the front and rear panel jacks, including the TX EQ and other settings, an AF mute, VOX on/off, split/up 2, and clear split. I leave my M1-M4 buttons for message uses and also use them as frequency presets within bands using the Elecraft K3 Freq Memory Editor program. Commander is the rig control program within a suite of free programs that include logging, a DX spot database, digital mode and CW support, propagation, and others. http://www.dxlabsuite.com/ Having said that, I still use PF1 and PF2 (RIT and XIT hold, respectively) on my K3 to set the TX power to 45W or full power. The PF1 gives me a starting point to drive my amplifier, and PF2 sets the K3 to full power for "barefoot" operation. I have referred to the K3 Programming Manual, but I admit that's a bit "hard core" for someone not wanting to get that involved. Jim N7US -Original Message- Age notwithstanding, many of us find messing with macros or other 'programming' activities right up there in desirability with hauling out the trash. Perhaps it would be possible for Elecraft to start building a macro library. Even if a macro isn't exactly what you want, it's often a lot easier to make a small change than to start from scratch. Ron AC7AC -Original Message- It is tough to get old and find most of your electronics know-how is out of date- so much so that creating a macro from scratch seems beyond my ken. APF is a very useful function, and I use it along with RIT as the fine tuning mechanism. How would one generate and execute as either a macro, or PF1/PF2, to turn on and off a "APF and RIT activated" function? BIll Hartman N6FB __ 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
Re: [Elecraft] APF Macro
Send me your macros and I'll put them up on ke7x.com Fred Cady fcady at ieee dot org > -Original Message- > From: elecraft-boun...@mailman.qth.net > [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Ron > D'Eau Claire > Sent: Saturday, February 12, 2011 4:14 PM > To: elecraft@mailman.qth.net > Subject: Re: [Elecraft] APF Macro > > Age notwithstanding, many of us find messing with macros or other > 'programming' activities right up there in desirability with > hauling out the > trash. > > Perhaps it would be possible for Elecraft to start building a > macro library. > Even if a macro isn't exactly what you want, it's often a lot > easier to make > a small change than to start from scratch. > > Ron AC7AC > > __ 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
Re: [Elecraft] APF Macro
Age notwithstanding, many of us find messing with macros or other 'programming' activities right up there in desirability with hauling out the trash. Perhaps it would be possible for Elecraft to start building a macro library. Even if a macro isn't exactly what you want, it's often a lot easier to make a small change than to start from scratch. Ron AC7AC -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of n...@aol.com Sent: Saturday, February 12, 2011 2:56 PM To: elecraft@mailman.qth.net Subject: [Elecraft] APF Macro It is tough to get old and find most of your electronics know-how is out of date- so much so that creating a macro from scratch seems beyond my ken. APF is a very useful function, and I use it along with RIT as the fine tuning mechanism. How would one generate and execute as either a macro, or PF1/PF2, to turn on and off a "APF and RIT activated" function? BIll Hartman N6FB __ 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 This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[Elecraft] APF Macro
It is tough to get old and find most of your electronics know-how is out of date- so much so that creating a macro from scratch seems beyond my ken. APF is a very useful function, and I use it along with RIT as the fine tuning mechanism. How would one generate and execute as either a macro, or PF1/PF2, to turn on and off a "APF and RIT activated" function? BIll Hartman N6FB __ 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
Re: [Elecraft] APF measurements: FW 4.17 better results by 2 dB
Bill, the K3s dBv and AF Mv meters are true RMS. We added that feature for automated MDS testing in K3 production. 73, Eric www.elecraft.com _..._ On Jan 27, 2011, at 11:17 AM, Bill W4ZV wrote: > > > Arie Kleingeld PA3A-2 wrote: >> >> I have no lab equipment but I have a K3 with dBV measurements, XG2 and >> the stepped attenuator from elecraft. >> > > Arie I believe you may have some measurement error. I'm sure you know that > noise can only be measured correctly with a True RMS responding > meter...which is not what is in the K3 dBV meter. This is the only way I > can reconcile any difference based on N1EU's measurements: > >> __ 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
Re: [Elecraft] APF Really Works
Thank goodness (and Elecraft) most of the DXpeditions these days are packing K3s. That means I stand a chance that they'll hear little pistols like me! 73, Ken Alexander VE3HLS --- On Fri, 1/28/11, Elliott Lawrence wrote: > Just worked VP8ORK on 12cw. No copy without the APF. Workable with > it > Other spots saying only esp. Guess they weren't using a K3!!! __ 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
Re: [Elecraft] APF Really Works
Elliott, Congratulations on working VP8ORK ! I hope to work them also, armed with my K3 APF battle gear. 73, Bob K6UJ On Jan 28, 2011, at 12:46 PM, Elliott Lawrence wrote: > Just worked VP8ORK on 12cw. No copy without the APF. Workable with it > Other spots saying only esp. Guess they weren't using a K3!!! > > Thanks again to Wayne and Eric for an outstanding radio. > > 73 > Elliott WA6TLA > > __ > 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 This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[Elecraft] APF Really Works
Just worked VP8ORK on 12cw. No copy without the APF. Workable with it Other spots saying only esp. Guess they weren't using a K3!!! Thanks again to Wayne and Eric for an outstanding radio. 73 Elliott WA6TLA __ 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
Re: [Elecraft] APF re-check: Rev. 4.17 vs. 4.25 (no difference found)
I am not smart enough to comment regarding the real stuff going on behind the sceines in the code. However, since the new update the NR and NB pretty much take care of my Plasma TV noise. So there is something that changed in the combination and I say thanks for this improvement. Don KD8NNU On Fri, Jan 28, 2011 at 11:57 AM, Wayne Burdick wrote: > Lyle (KK7P), our DSP engineer--a very meticulous guy--just did a very > careful re-test of the two versions of code referred to in this > thread. He found no difference between 4.17 and 4.25. > > I see that Arie (PA3A) also confirmed no difference when he repeated > his own test. (Thanks for doing this, Arie.) > > 73, > Wayne > N6KR > > > On Jan 28, 2011, at 2:51 AM, Arie Kleingeld PA3A wrote: > >> All, >> >> Measured the two FW's 4.17 and 4.25 with APF on S+N/N ratio at MDS >> again, and again. >> Question was: if the filter plots are exactly the same, where does >> the >> measured (marginal) difference of 2 dB come from? >> >> Found no difference this time. Seems that the XG2 drifted a bit in >> yesterdays measurements which, I think, caused the 2dB difference >> (despite tuning the K3 on the right freq before measurement started). >> >> Positive thing is that I could measure the improvement of S+N/N ratio >> with the APF switched on. Even with the 200Hz roofer and 50Hz DSP BW >> it >> adds a few dB. So for me it is a good tool for digging holes in the >> noise looking for weak signals. >> >> 73, >> Arie PA3A >> >> >> >> >> __ >> 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 > > 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 This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[Elecraft] APF re-check: Rev. 4.17 vs. 4.25 (no difference found)
Lyle (KK7P), our DSP engineer--a very meticulous guy--just did a very careful re-test of the two versions of code referred to in this thread. He found no difference between 4.17 and 4.25. I see that Arie (PA3A) also confirmed no difference when he repeated his own test. (Thanks for doing this, Arie.) 73, Wayne N6KR On Jan 28, 2011, at 2:51 AM, Arie Kleingeld PA3A wrote: > All, > > Measured the two FW's 4.17 and 4.25 with APF on S+N/N ratio at MDS > again, and again. > Question was: if the filter plots are exactly the same, where does the > measured (marginal) difference of 2 dB come from? > > Found no difference this time. Seems that the XG2 drifted a bit in > yesterdays measurements which, I think, caused the 2dB difference > (despite tuning the K3 on the right freq before measurement started). > > Positive thing is that I could measure the improvement of S+N/N ratio > with the APF switched on. Even with the 200Hz roofer and 50Hz DSP BW > it > adds a few dB. So for me it is a good tool for digging holes in the > noise looking for weak signals. > > 73, > Arie PA3A > > > > > __ > 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 This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] APF measurements: FW 4.17 vs FW4.25 revisited
PA3A wrote: > Measured the two FW's 4.17 and 4.25 with APF on S+N/N ratio at MDS again, and again. Question was: if the filter plots are exactly the same, where does the measured (marginal) difference of 2 dB come from? > Found no difference this time. Seems that the XG2 drifted a bit in yesterdays measurements which, I think, caused the 2dB difference (despite tuning the K3 on the right freq before measurement started). Measurements don't lie when done properly. I should have thought about drift since peaking APF is so critical. I believe the lesson to be learned is to not blame the APF if it doesn't work like our memories think it did previously. Look elsewhere for other reasons...such as: 1. The character of the noise (atmospheric vs galactic). 2. Operator error (gain and/or bandwidth settings, tuning errors, etc). Human nature is to blame anything but ourselves. http://www.igopogo.com/we_have_met.htm > Positive thing is that I could measure the improvement of S+N/N ratio with the APF switched on. Even with the 200Hz roofer and 50Hz DSP BW it adds a few dB. So for me it is a good tool for digging holes in the noise looking for weak signals. Yes it definitely helps. Conditions on 160 were excellent last night so hopefully they will hold for the contest. RV9CX, UA9MA and 4L/UT5EO were all worked with decent signals. I also heard UN5J in deep Central Asia (near the BY border) for the first time since 1997! 73, Bill -- View this message in context: http://elecraft.365791.n2.nabble.com/APF-tp5963894p5969558.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
[Elecraft] APF measurements: FW 4.17 vs FW4.25 revisited
All, Measured the two FW's 4.17 and 4.25 with APF on S+N/N ratio at MDS again, and again. Question was: if the filter plots are exactly the same, where does the measured (marginal) difference of 2 dB come from? Found no difference this time. Seems that the XG2 drifted a bit in yesterdays measurements which, I think, caused the 2dB difference (despite tuning the K3 on the right freq before measurement started). Positive thing is that I could measure the improvement of S+N/N ratio with the APF switched on. Even with the 200Hz roofer and 50Hz DSP BW it adds a few dB. So for me it is a good tool for digging holes in the noise looking for weak signals. 73, Arie PA3A __ 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
Re: [Elecraft] APF measurements: FW 4.17 better results by 2 dB
Bill, I am not suggesting Elecraft do anything other than the explanations that have already transpired. Yet even with such dialog and tests that say "Q. E. D.", there will be many who remain unconvinced, and will want to stick with the old version "because it is better". They will not be convinced until they have received countering information with their own ears. There may be other factors involved -- although there were no intentional changes in the DSP firmware to change the noise response of the K3, that is one possible factor that comes to mind. Another factor is operator induced -- it is known that the 50 Hz filter has some ringing which will change minute by minute with band noise. Add APF on top of that, and the perception from one moment to another can be all "over the map". I believe the test data, and look seriously for other factors that may influence the perception of "better or worse" when confronted with the facts that things (like APF) are equal. I believe Wayne has explained that there are many variables (QSB, band noise) that can influence the final APF response, and to my mind, that is sufficient. But there will be those who will remain unconvinced and will continue to use 4.16 because the APF is "better". There is no cure for perceptions - it is just something to be accepted. Pixie dust may help, measurements will not. 73, Don W3FPR On 1/27/2011 7:55 PM, Bill W4ZV wrote: > > Don Wilhelm-4 wrote: >> I had a sage manager many years ago who often stated "Perception is 99% >> of reality". Being of a scientific mind, I had my doubts at the time >> thinking "people will be convinced by the facts of science". >> In later years, I have mellowed and now agree with that manager. >> Perception IS 99% of reality! >> > OK let's follow your logic. Let's assume Elecraft now wants to duplicate > the "magical" 4.16 APF performance. The firmware code is identical > according to the author and the frequency response curve is identical. What > do you suggest they do? Sprinkle pixie dust? > > 73, Bill __ 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
Re: [Elecraft] APF measurements: FW 4.17 better results by 2 dB
Don Wilhelm-4 wrote: > > I had a sage manager many years ago who often stated "Perception is 99% > of reality". Being of a scientific mind, I had my doubts at the time > thinking "people will be convinced by the facts of science". > In later years, I have mellowed and now agree with that manager. > Perception IS 99% of reality! > OK let's follow your logic. Let's assume Elecraft now wants to duplicate the "magical" 4.16 APF performance. The firmware code is identical according to the author and the frequency response curve is identical. What do you suggest they do? Sprinkle pixie dust? 73, Bill -- View this message in context: http://elecraft.365791.n2.nabble.com/APF-tp5963894p5968368.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
Re: [Elecraft] APF measurements: FW 4.17 better results by 2 dB
But Bill, I had a sage manager many years ago who often stated "Perception is 99% of reality". Being of a scientific mind, I had my doubts at the time thinking "people will be convinced by the facts of science". In later years, I have mellowed and now agree with that manager. Perception IS 99% of reality! 73, Don W3FPR On 1/27/2011 7:28 PM, Bill W4ZV wrote: > > Barry N1EU wrote: >> 4.16 APF has the same response curve as all the other versions. >> > Q.E.D. If it has an identical response curve it has identical S/N > performance. Anything else is either differences in noise conditions or > human imagination. > > 73, Bill > > __ 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
Re: [Elecraft] APF measurements: FW 4.17 better results by 2 dB
Barry N1EU wrote: > > 4.16 APF has the same response curve as all the other versions. > Q.E.D. If it has an identical response curve it has identical S/N performance. Anything else is either differences in noise conditions or human imagination. 73, Bill -- View this message in context: http://elecraft.365791.n2.nabble.com/APF-tp5963894p5968319.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
Re: [Elecraft] APF measurements: FW 4.17 better results by 2 dB
4.16 APF has the same response curve as all the other versions. BArry N1EU On Thu, Jan 27, 2011 at 8:16 PM, Barry N1EU wrote: > I'll check the APF in 4.16 after work and see if it's any different. > > Barry N1EU > > > On Thu, Jan 27, 2011 at 7:58 PM, Steve Ellington [via Elecraft] < > ml-node+5967599-613958550-2...@n2.nabble.com > > wrote: > >> FW pre-beta 4.16 release was actually the first to have APF, not 4.17. >> Here's an interesting comment made shortly APF was finally released to the >> >> public. >> http://elecraft.365791.n2.nabble.com/K3-APF-td5735159.html#a5736718<http://elecraft.365791.n2.nabble.com/K3-APF-td5735159.html?by-user=t#a5736718> >> >> >> >> Steve >> N4LQ >> - Original Message - >> From: "Arie Kleingeld PA3A" <[hidden >> email]<http://user/SendEmail.jtp?type=node&node=5967599&i=0>> >> >> To: <[hidden email]<http://user/SendEmail.jtp?type=node&node=5967599&i=1>> >> >> Sent: Thursday, January 27, 2011 6:44 AM >> Subject: [Elecraft] APF measurements: FW 4.17 better results by 2 dB >> >> >> > Hello all, >> > >> > Did some measurements on the different frimware versions. This time not >> > a BW-plot but I measured S+N/N ratio's. >> > >> > >> > I have no lab equipment but I have a K3 with dBV measurements, XG2 and >> > the stepped attenuator from elecraft. >> > I measured the difference of the K3 dBV-reading in signal off (=N) and >> > signal on (=S+N) >> > AGC off, mode CW, 400Hz BW and 400Hz Roofing. >> > RX gain of the K3 has been calibrated with XG2 and the K3 utility. >> > >> > >> > This is what I found. >> > >> > _FW 4.25 and 4.21 (both give the same measurement values):_ >> > At MDS level (stepped att on 20dB to reach this level) >> > normal 400 Hz BW: S+N/N = 3dB (as expected, hi) >> > 400 Hz BW + dual PB: S+N/N = 10 dB >> > >> > Now signal level 6dB under MDS (26dB att instead of 20dB): >> > normal 400 Hz BW: S+N/N = 0.5 dB >> > 400 Hz BW + dual PB: S+N/N = 4 dB >> > >> > >> > _FW 4.17_ >> > At MDS level (stepped att on 20dB) >> > normal 400 Hz BW: S+N/N = 3dB (as expected) >> > 400 Hz BW + dual PB: S+N/N = 12 dB (THIS is 2 dB BETTER) >> > >> > Now signal level 6dB under MDS: >> > normal 400 Hz BW: S+N/N = 0.5 dB >> > 400 Hz BW + dual PB: S+N/N = 6 dB (THIS is 2dB BETTER) >> > >> > >> > There are probably people that can measure this far more better than I >> > did with better equipment. >> > But this is what I can come up with here. >> > >> > 73, >> > Arie PA3A >> > >> > >> > >> > Op 27-1-2011 0:52, Barry N1EU schreef: >> >> Forget it - full stop! >> >> >> >> I just ran a spectral analysis of the current firmware versus the very >> >> first >> >> APF implementation (mcu 4.17 dsp 2.65) from 11/3/10 AND THE PLOTS ARE >> >> ABSOLUTELY CONGRUOUS! The APF implementation hasn't changed a bit (or >> a >> >> byte). >> >> >> >> Have a look: http://n1eu.com/k3apf.gif >> >> >> >> magenta and green plots are taken with width = 200hz >> >> aqua and yellow plots are taken with width = 100hz >> >> >> >> Barry N1EU >> > __ >> > Elecraft mailing list >> > Home: http://mailman.qth.net/mailman/listinfo/elecraft >> > Help: http://mailman.qth.net/mmfaq.htm >> > Post: mailto:[hidden >> > email]<http://user/SendEmail.jtp?type=node&node=5967599&i=2> >> > >> > 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:[hidden >> email]<http://user/SendEmail.jtp?type=node&node=5967599&i=3> >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> >> >> -- >> If you reply to this email, your message will be added to the discussion >> below: >> http://elecraft.365791.n2.nabble.com/APF-tp5963894p5967599.html >> To unsubscribe from APF, click >> here<http://elecraft.365791.n2.nabble.com/template/NamlServlet.jtp?macro=unsubscribe_by_code&node=5963894&code=YmFycnkubjFldUBnbWFpbC5jb218NTk2Mzg5NHwtMTUyMTIxNjYw>. >> >> > > __ 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
Re: [Elecraft] APF measurements: FW 4.17 better results by 2 dB
Within the band-limited audio passband of the K3, the RMS metering is very accurate. The algorithm is: 1) measure and square each reading 2) sum with the previous readings (accumulate) 3) do this for 500 ms or 1 sec 4) divide the sum by the number of samples taken 5) compute the square root 6) clear the accumulator It tracked my HP 34401A to within 0.1 dB during measurements taken while developing and validating the DSP code. 73, Lyle KK7P >> "AFV shows the true RMS value of receiver AF output (mVp-p), unaffected by >> AF GAIN control. " >> > While that may be true for sinusoidal signals I doubt it holds for noise > measurements... There is a way to do true RMS with a DSP but would > require a much wider bandwidth (i.e. higher sampling rate) than the K3 uses. > __ 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
Re: [Elecraft] APF measurements: FW 4.17 better results by 2 dB
Hi, Doing true RMS over the selected passband is very easy to do with DSP and I have no reason to doubt that the K3 dBV meter is a very close approximation to true RMS even on signals that are far from sinusoidal (such as noise). Analog is a different story and I agree that there are many false claims to be "true RMS". AB2TC - Knut Bill W4ZV wrote: > > > While that may be true for sinusoidal signals I doubt it holds for noise > measurements. Accurate noise measurements require a "true RMS-responding" > meter...not a peak-responding or average-responding meter calibrated to > display RMS for sinusoidal waves (only). Many DMMs throw around the term > "true RMS" but are actually NOT true RMS-responding (which is required for > accurate noise measurement). True RMS meters are much more expensive and > will measure both sinusoidal and non-sinusoidal signals including noise. > Most analog DMMS use thermocouples to determine the heating value (or > energy content) of signals. There is a way to do true RMS with a DSP but > would require a much wider bandwidth (i.e. higher sampling rate) than the > K3 uses. > > 73, Bill > -- View this message in context: http://elecraft.365791.n2.nabble.com/APF-tp5963894p5968012.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
Re: [Elecraft] APF measurements: FW 4.17 better results by 2 dB
Bill, Thanks for your added comments. As I said, I do not have the lab equipment to do this. But there are people in this group that have and can measure far better than I. The APF (for me) is not about selectivity. I use it when digging into the noise and get a better copy of weak signals. That is why I tried to measure S+N/N ratio the best I could. So if it is not exactly 2 dB (it is not), I donot care. I just measured that there was a _difference_ that 4.17 did a better job on s+n/n ratio. So if one of the pro's can measure this more scientifically, that would be very enlighting. If this s+n/n ratio and the passband are the same, then we can stop this discussion about the apf. :-) 73 Arie > > "Conclusions > > The model and the experimental results both suggest that these and similar > multimeter are not capable of single high resolution relative measurements > of narrowband audio noise such as measuring S/N ratios or Y factor for noise > figure measurement due mainly to the short integration time in combination > with narrow bandwidth. > > It may be possible to improve resolution by taking multiple measurements and > calculating the root of the mean of the squares of the measurements, but > errors in the summary process and in temporal drift become an issue." > > 73, Bill > __ 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
Re: [Elecraft] APF measurements: FW 4.17 better results by 2 dB
Scott Ellington wrote: > > Page 36 of the K3 owner's manual: > > "AFV shows the true RMS value of receiver AF output (mVp-p), unaffected by > AF GAIN control. " > While that may be true for sinusoidal signals I doubt it holds for noise measurements. Accurate noise measurements require a "true RMS-responding" meter...not a peak-responding or average-responding meter calibrated to display RMS for sinusoidal waves (only). Many DMMs throw around the term "true RMS" but are actually NOT true RMS-responding (which is required for accurate noise measurement). True RMS meters are much more expensive and will measure both sinusoidal and non-sinusoidal signals including noise. Most analog DMMS use thermocouples to determine the heating value (or energy content) of signals. There is a way to do true RMS with a DSP but would require a much wider bandwidth (i.e. higher sampling rate) than the K3 uses. 73, Bill -- View this message in context: http://elecraft.365791.n2.nabble.com/APF-tp5963894p5967684.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
Re: [Elecraft] APF measurements: FW 4.17 better results by 2 dB
I'll check the APF in 4.16 after work and see if it's any different. Barry N1EU On Thu, Jan 27, 2011 at 7:58 PM, Steve Ellington [via Elecraft] < ml-node+5967599-613958550-2...@n2.nabble.com > wrote: > FW pre-beta 4.16 release was actually the first to have APF, not 4.17. > Here's an interesting comment made shortly APF was finally released to the > public. > http://elecraft.365791.n2.nabble.com/K3-APF-td5735159.html#a5736718<http://elecraft.365791.n2.nabble.com/K3-APF-td5735159.html?by-user=t#a5736718> > > > > Steve > N4LQ > - Original Message - > From: "Arie Kleingeld PA3A" <[hidden > email]<http://user/SendEmail.jtp?type=node&node=5967599&i=0>> > > To: <[hidden email] <http://user/SendEmail.jtp?type=node&node=5967599&i=1>> > > Sent: Thursday, January 27, 2011 6:44 AM > Subject: [Elecraft] APF measurements: FW 4.17 better results by 2 dB > > > > Hello all, > > > > Did some measurements on the different frimware versions. This time not > > a BW-plot but I measured S+N/N ratio's. > > > > > > I have no lab equipment but I have a K3 with dBV measurements, XG2 and > > the stepped attenuator from elecraft. > > I measured the difference of the K3 dBV-reading in signal off (=N) and > > signal on (=S+N) > > AGC off, mode CW, 400Hz BW and 400Hz Roofing. > > RX gain of the K3 has been calibrated with XG2 and the K3 utility. > > > > > > This is what I found. > > > > _FW 4.25 and 4.21 (both give the same measurement values):_ > > At MDS level (stepped att on 20dB to reach this level) > > normal 400 Hz BW: S+N/N = 3dB (as expected, hi) > > 400 Hz BW + dual PB: S+N/N = 10 dB > > > > Now signal level 6dB under MDS (26dB att instead of 20dB): > > normal 400 Hz BW: S+N/N = 0.5 dB > > 400 Hz BW + dual PB: S+N/N = 4 dB > > > > > > _FW 4.17_ > > At MDS level (stepped att on 20dB) > > normal 400 Hz BW: S+N/N = 3dB (as expected) > > 400 Hz BW + dual PB: S+N/N = 12 dB (THIS is 2 dB BETTER) > > > > Now signal level 6dB under MDS: > > normal 400 Hz BW: S+N/N = 0.5 dB > > 400 Hz BW + dual PB: S+N/N = 6 dB (THIS is 2dB BETTER) > > > > > > There are probably people that can measure this far more better than I > > did with better equipment. > > But this is what I can come up with here. > > > > 73, > > Arie PA3A > > > > > > > > Op 27-1-2011 0:52, Barry N1EU schreef: > >> Forget it - full stop! > >> > >> I just ran a spectral analysis of the current firmware versus the very > >> first > >> APF implementation (mcu 4.17 dsp 2.65) from 11/3/10 AND THE PLOTS ARE > >> ABSOLUTELY CONGRUOUS! The APF implementation hasn't changed a bit (or a > > >> byte). > >> > >> Have a look: http://n1eu.com/k3apf.gif > >> > >> magenta and green plots are taken with width = 200hz > >> aqua and yellow plots are taken with width = 100hz > >> > >> Barry N1EU > > __ > > Elecraft mailing list > > Home: http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/mmfaq.htm > > Post: mailto:[hidden > > email]<http://user/SendEmail.jtp?type=node&node=5967599&i=2> > > > > 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:[hidden > email]<http://user/SendEmail.jtp?type=node&node=5967599&i=3> > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > > > -- > If you reply to this email, your message will be added to the discussion > below: > http://elecraft.365791.n2.nabble.com/APF-tp5963894p5967599.html > To unsubscribe from APF, click > here<http://elecraft.365791.n2.nabble.com/template/NamlServlet.jtp?macro=unsubscribe_by_code&node=5963894&code=YmFycnkubjFldUBnbWFpbC5jb218NTk2Mzg5NHwtMTUyMTIxNjYw>. > > __ 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
Re: [Elecraft] APF measurements: FW 4.17 better results by 2 dB
FW pre-beta 4.16 release was actually the first to have APF, not 4.17. Here's an interesting comment made shortly APF was finally released to the public. http://elecraft.365791.n2.nabble.com/K3-APF-td5735159.html#a5736718 Steve N4LQ - Original Message - From: "Arie Kleingeld PA3A" To: Sent: Thursday, January 27, 2011 6:44 AM Subject: [Elecraft] APF measurements: FW 4.17 better results by 2 dB > Hello all, > > Did some measurements on the different frimware versions. This time not > a BW-plot but I measured S+N/N ratio's. > > > I have no lab equipment but I have a K3 with dBV measurements, XG2 and > the stepped attenuator from elecraft. > I measured the difference of the K3 dBV-reading in signal off (=N) and > signal on (=S+N) > AGC off, mode CW, 400Hz BW and 400Hz Roofing. > RX gain of the K3 has been calibrated with XG2 and the K3 utility. > > > This is what I found. > > _FW 4.25 and 4.21 (both give the same measurement values):_ > At MDS level (stepped att on 20dB to reach this level) > normal 400 Hz BW: S+N/N = 3dB (as expected, hi) > 400 Hz BW + dual PB: S+N/N = 10 dB > > Now signal level 6dB under MDS (26dB att instead of 20dB): > normal 400 Hz BW: S+N/N = 0.5 dB > 400 Hz BW + dual PB: S+N/N = 4 dB > > > _FW 4.17_ > At MDS level (stepped att on 20dB) > normal 400 Hz BW: S+N/N = 3dB (as expected) > 400 Hz BW + dual PB: S+N/N = 12 dB (THIS is 2 dB BETTER) > > Now signal level 6dB under MDS: > normal 400 Hz BW: S+N/N = 0.5 dB > 400 Hz BW + dual PB: S+N/N = 6 dB (THIS is 2dB BETTER) > > > There are probably people that can measure this far more better than I > did with better equipment. > But this is what I can come up with here. > > 73, > Arie PA3A > > > > Op 27-1-2011 0:52, Barry N1EU schreef: >> Forget it - full stop! >> >> I just ran a spectral analysis of the current firmware versus the very >> first >> APF implementation (mcu 4.17 dsp 2.65) from 11/3/10 AND THE PLOTS ARE >> ABSOLUTELY CONGRUOUS! The APF implementation hasn't changed a bit (or a >> byte). >> >> Have a look: http://n1eu.com/k3apf.gif >> >> magenta and green plots are taken with width = 200hz >> aqua and yellow plots are taken with width = 100hz >> >> Barry N1EU > __ > 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 This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] APF measurements: FW 4.17 better results by 2 dB
Page 36 of the K3 owner's manual: "AFV shows the true RMS value of receiver AF output (mVp-p), unaffected by AF GAIN control. " 73, Scott K9MA On Jan 27, 2011, at 1:17 PM, Bill W4ZV wrote: > I'm sure you know that > noise can only be measured correctly with a True RMS responding > meter...which is not what is in the K3 dBV meter. Scott Ellington Madison, Wisconsin USA __ 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
Re: [Elecraft] APF measurements: FW 4.17 better results by 2 dB
Arie Kleingeld PA3A-2 wrote: > > I have no lab equipment but I have a K3 with dBV measurements, XG2 and > the stepped attenuator from elecraft. > Arie I believe you may have some measurement error. I'm sure you know that noise can only be measured correctly with a True RMS responding meter...which is not what is in the K3 dBV meter. This is the only way I can reconcile any difference based on N1EU's measurements: > I just ran a spectral analysis of the current firmware versus the very > first > APF implementation (mcu 4.17 dsp 2.65) from 11/3/10 AND THE PLOTS ARE > ABSOLUTELY CONGRUOUS! The APF implementation hasn't changed a bit (or a > byte). > > Have a look: http://n1eu.com/k3apf.gif If the APF filter responses are identical, your S/N measurements should also be identical. http://vk1od.net/measurement/noise/multimeter.htm "Conclusions The model and the experimental results both suggest that these and similar multimeter are not capable of single high resolution relative measurements of narrowband audio noise such as measuring S/N ratios or Y factor for noise figure measurement due mainly to the short integration time in combination with narrow bandwidth. It may be possible to improve resolution by taking multiple measurements and calculating the root of the mean of the squares of the measurements, but errors in the summary process and in temporal drift become an issue." 73, Bill -- View this message in context: http://elecraft.365791.n2.nabble.com/APF-tp5963894p5967466.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
Re: [Elecraft] APF measurements: FW 4.17 better results by 2 dB
All, where I mentioned Dual PB, I mean ofcourse the APF, because that the discussion here. Sorry If that is not clear. 73 Arie PA3A Op 27-1-2011 12:44, Arie Kleingeld PA3A schreef: > Hello all, > > Did some measurements on the different frimware versions. This time not > a BW-plot but I measured S+N/N ratio's. > > > I have no lab equipment but I have a K3 with dBV measurements, XG2 and > the stepped attenuator from elecraft. > I measured the difference of the K3 dBV-reading in signal off (=N) and > signal on (=S+N) > AGC off, mode CW, 400Hz BW and 400Hz Roofing. > RX gain of the K3 has been calibrated with XG2 and the K3 utility. > > > This is what I found. > > _FW 4.25 and 4.21 (both give the same measurement values):_ > At MDS level (stepped att on 20dB to reach this level) > normal 400 Hz BW: S+N/N = 3dB (as expected, hi) > 400 Hz BW + dual PB: S+N/N = 10 dB > > Now signal level 6dB under MDS (26dB att instead of 20dB): > normal 400 Hz BW: S+N/N = 0.5 dB > 400 Hz BW + dual PB: S+N/N = 4 dB > > > _FW 4.17_ > At MDS level (stepped att on 20dB) > normal 400 Hz BW: S+N/N = 3dB (as expected) > 400 Hz BW + dual PB: S+N/N = 12 dB (THIS is 2 dB BETTER) > > Now signal level 6dB under MDS: > normal 400 Hz BW: S+N/N = 0.5 dB > 400 Hz BW + dual PB: S+N/N = 6 dB (THIS is 2dB BETTER) > > > There are probably people that can measure this far more better than I > did with better equipment. > But this is what I can come up with here. > > 73, > Arie PA3A > > > > Op 27-1-2011 0:52, Barry N1EU schreef: >> Forget it - full stop! >> >> I just ran a spectral analysis of the current firmware versus the very first >> APF implementation (mcu 4.17 dsp 2.65) from 11/3/10 AND THE PLOTS ARE >> ABSOLUTELY CONGRUOUS! The APF implementation hasn't changed a bit (or a >> byte). >> >> Have a look: http://n1eu.com/k3apf.gif >> >> magenta and green plots are taken with width = 200hz >> aqua and yellow plots are taken with width = 100hz >> >> Barry N1EU > __ > 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 This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[Elecraft] APF
Good advice from N1EU and K2AV here, folks! Also, see Wayne's posting: "Tips for using APF." I'm a junkie for trying out new firmware, and I can attest that the APF is as good as it ever was-- in fact you need the latest version of it to be sure you have the 5 Hz resolution in the APF shift control. Other pre-requisites for success with APF are using FINE tune (1 Hz frequency resolution) and also shifting the signal frequency (using RIT and APF shift) ) slightly off the ringing frequency. 73, Chuck Guenther NI0C K3 s/n 1061 Barry, N1EU wrote: " Forget it - full stop! I just ran a spectral analysis of the current firmware versus the very first APF implementation (mcu 4.17 dsp 2.65) from 11/3/10 AND THE PLOTS ARE ABSOLUTELY CONGRUOUS! The APF implementation hasn't changed a bit (or a byte)." Guy, K2AV wrote: " May I suggest that one of the necessities of using APF is to throttle back the RF gain so that the AGC is not pushing up the noise to the level of forcing what sounds like ringing. When I'm hearing what sounds like ringing, moving back the RF gain (or removing PRE, or using ATT) will usually clear it up. Using slow AGC usually does NOT help much, but backing off RF gain so the background noise is only moderate or less usually helps." __ 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] APF measurements: FW 4.17 better results by 2 dB
Hello all, Did some measurements on the different frimware versions. This time not a BW-plot but I measured S+N/N ratio's. I have no lab equipment but I have a K3 with dBV measurements, XG2 and the stepped attenuator from elecraft. I measured the difference of the K3 dBV-reading in signal off (=N) and signal on (=S+N) AGC off, mode CW, 400Hz BW and 400Hz Roofing. RX gain of the K3 has been calibrated with XG2 and the K3 utility. This is what I found. _FW 4.25 and 4.21 (both give the same measurement values):_ At MDS level (stepped att on 20dB to reach this level) normal 400 Hz BW: S+N/N = 3dB (as expected, hi) 400 Hz BW + dual PB: S+N/N = 10 dB Now signal level 6dB under MDS (26dB att instead of 20dB): normal 400 Hz BW: S+N/N = 0.5 dB 400 Hz BW + dual PB: S+N/N = 4 dB _FW 4.17_ At MDS level (stepped att on 20dB) normal 400 Hz BW: S+N/N = 3dB (as expected) 400 Hz BW + dual PB: S+N/N = 12 dB (THIS is 2 dB BETTER) Now signal level 6dB under MDS: normal 400 Hz BW: S+N/N = 0.5 dB 400 Hz BW + dual PB: S+N/N = 6 dB (THIS is 2dB BETTER) There are probably people that can measure this far more better than I did with better equipment. But this is what I can come up with here. 73, Arie PA3A Op 27-1-2011 0:52, Barry N1EU schreef: > Forget it - full stop! > > I just ran a spectral analysis of the current firmware versus the very first > APF implementation (mcu 4.17 dsp 2.65) from 11/3/10 AND THE PLOTS ARE > ABSOLUTELY CONGRUOUS! The APF implementation hasn't changed a bit (or a > byte). > > Have a look: http://n1eu.com/k3apf.gif > > magenta and green plots are taken with width = 200hz > aqua and yellow plots are taken with width = 100hz > > Barry N1EU __ 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
Re: [Elecraft] APF
Hi Barry, I'm curious too. This has come up before. I'd be interested in what you see. 73, Bob K6UJ On Jan 26, 2011, at 3:12 PM, Barry N1EU wrote: > > Okay, what version of firmware has the "original" APF that worked better for > you guys? I'll try and run a spectral comparison of the two and post the > results. I'm skeptical that there's a difference but I'm willing to give it > a go. > > Barry N1EU > > > juergen piezo wrote: >> >> I like you cant get the same results with the current release of the APF >> that I go with the original. >> > > -- > View this message in context: > http://elecraft.365791.n2.nabble.com/APF-tp5963894p5964585.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 __ 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
Re: [Elecraft] APF
John, What is the firmware version number of the earlier one that the APF worked the best ? I'm thinking about trying the APF out in this version. thanks, Bob K6UJ On Jan 26, 2011, at 12:19 PM, juergen wrote: > Hi Dave > > I asked the same question. > > The gurus at Elecraft indicated that nothing had changed. I still have the > original firmware and load it up in my spare K3. The original version is the > ESP version that works for me. > > I like you cant get the same results with the current release of the APF that > I go with the original. The original blew my socks off I was so impressed > with it. I have done the comparison test so many times now that I know that > the original was the better release and its not my imagination. > > If the programmer says the hex code is the same then there must be some other > factors at play. I dont really have the answer. I am keeping the original > firmware just for contests. > > 73 > John > > > > --- On Wed, 1/26/11, David Lear wrote: > >> From: David Lear >> Subject: [Elecraft] APF >> To: Elecraft@mailman.qth.net >> Date: Wednesday, January 26, 2011, 11:27 AM >> Did anything change with APF in the >> latest release ? Seemed to perform >> better before rev 2.45. Maybe I 'm just loosing my touch. >> >> 73 Dave Lear NE5DL >> >> __ >> 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 > > 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 This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] APF
May I suggest that one of the necessities of using APF is to throttle back the RF gain so that the AGC is not pushing up the noise to the level of forcing what sounds like ringing. When I'm hearing what sounds like ringing, moving back the RF gain (or removing PRE, or using ATT) will usually clear it up. Using slow AGC usually does NOT help much, but backing off RF gain so the background noise is only moderate or less usually helps. 73, Guy. On Wed, Jan 26, 2011 at 6:52 PM, Barry N1EU wrote: > > Forget it - full stop! > > I just ran a spectral analysis of the current firmware versus the very > first > APF implementation (mcu 4.17 dsp 2.65) from 11/3/10 AND THE PLOTS ARE > ABSOLUTELY CONGRUOUS! The APF implementation hasn't changed a bit (or a > byte). > > Have a look: http://n1eu.com/k3apf.gif > > magenta and green plots are taken with width = 200hz > aqua and yellow plots are taken with width = 100hz > > Barry N1EU > -- > View this message in context: > http://elecraft.365791.n2.nabble.com/APF-tp5963894p5964669.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 > __ 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
Re: [Elecraft] APF
Forget it - full stop! I just ran a spectral analysis of the current firmware versus the very first APF implementation (mcu 4.17 dsp 2.65) from 11/3/10 AND THE PLOTS ARE ABSOLUTELY CONGRUOUS! The APF implementation hasn't changed a bit (or a byte). Have a look: http://n1eu.com/k3apf.gif magenta and green plots are taken with width = 200hz aqua and yellow plots are taken with width = 100hz Barry N1EU -- View this message in context: http://elecraft.365791.n2.nabble.com/APF-tp5963894p5964669.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
Re: [Elecraft] APF
Barry >From what I can tell. MCU 4.21/DSP 2.69/ etc. is when APF first appeared. I had the same experience. In fact, I was actually leaving APF on most of the time until the newer version came along. I loved it..Now I seldom use it because it does more harm than good. Maybe one's socks can only be blown off once? Steve N4LQ - Original Message - From: "Barry N1EU" To: Sent: Wednesday, January 26, 2011 6:12 PM Subject: Re: [Elecraft] APF > > Okay, what version of firmware has the "original" APF that worked better > for > you guys? I'll try and run a spectral comparison of the two and post the > results. I'm skeptical that there's a difference but I'm willing to give > it > a go. > > Barry N1EU > > > juergen piezo wrote: >> >> I like you cant get the same results with the current release of the APF >> that I go with the original. >> > > -- > View this message in context: > http://elecraft.365791.n2.nabble.com/APF-tp5963894p5964585.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 __ 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
Re: [Elecraft] APF
Gents, Even *I* thought something had changed. (Lyle, our DSP engineer, assured me that it hadn't. The code hasn't changed.) What's happening is that APF's effect is more obvious in the presence of certain band-noise conditions. These conditions will vary from band to band, and can change hourly, daily, maybe even monthly for a given QTH. I went back and listened the next day, and the APF was doing its job. I find it especially useful on the low bands, and many K3 owners have posted testimonials about this -- using the final version of the code. The APF algorithm, with its gradual slope and ~30 Hz wide peak, brings up a very narrow portion of the audio spectrum (around the center pitch) just a few dB, without bringing up the adjacent noise or causing a rapid phase transition. On several occasions I've measured a 3 to 5 dB improvement in S+N/N on weak signals using the K3's built-in audio voltmeter. 73, Wayne N6KR On Jan 26, 2011, at 12:19 PM, juergen wrote: > Hi Dave > > I asked the same question. > > The gurus at Elecraft indicated that nothing had changed. I still > have the original firmware and load it up in my spare K3. The > original version is the ESP version that works for me. > > I like you cant get the same results with the current release of the > APF that I go with the original. The original blew my socks off I > was so impressed with it. I have done the comparison test so many > times now that I know that the original was the better release and > its not my imagination. > > If the programmer says the hex code is the same then there must be > some other factors at play. I dont really have the answer. I am > keeping the original firmware just for contests. > > 73 > John > > > > --- On Wed, 1/26/11, David Lear wrote: > >> From: David Lear >> Subject: [Elecraft] APF >> To: Elecraft@mailman.qth.net >> Date: Wednesday, January 26, 2011, 11:27 AM >> Did anything change with APF in the >> latest release ? Seemed to perform >> better before rev 2.45. Maybe I 'm just loosing my touch. >> >> 73 Dave Lear NE5DL >> >> __ >> 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 > > 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 This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] APF
Okay, what version of firmware has the "original" APF that worked better for you guys? I'll try and run a spectral comparison of the two and post the results. I'm skeptical that there's a difference but I'm willing to give it a go. Barry N1EU juergen piezo wrote: > > I like you cant get the same results with the current release of the APF > that I go with the original. > -- View this message in context: http://elecraft.365791.n2.nabble.com/APF-tp5963894p5964585.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
Re: [Elecraft] APF
Hi John, I agree with you. 73 Detlef, DL7NDF Am 26.01.2011 21:19, schrieb juergen: > Hi Dave > > I asked the same question. > > The gurus at Elecraft indicated that nothing had changed. I still have the > original firmware and load it up in my spare K3. The original version is the > ESP version that works for me. > > I like you cant get the same results with the current release of the APF that > I go with the original. The original blew my socks off I was so impressed > with it. I have done the comparison test so many times now that I know that > the original was the better release and its not my imagination. > > If the programmer says the hex code is the same then there must be some other > factors at play. I dont really have the answer. I am keeping the original > firmware just for contests. > > 73 > John > > > > --- On Wed, 1/26/11, David Lear wrote: > >> From: David Lear >> Subject: [Elecraft] APF >> To: Elecraft@mailman.qth.net >> Date: Wednesday, January 26, 2011, 11:27 AM >> Did anything change with APF in the >> latest release ? Seemed to perform >> better before rev 2.45. Maybe I 'm just loosing my touch. >> >> 73 Dave Lear NE5DL >> >> __ >> 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 > > 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 This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] APF
Hi Dave I asked the same question. The gurus at Elecraft indicated that nothing had changed. I still have the original firmware and load it up in my spare K3. The original version is the ESP version that works for me. I like you cant get the same results with the current release of the APF that I go with the original. The original blew my socks off I was so impressed with it. I have done the comparison test so many times now that I know that the original was the better release and its not my imagination. If the programmer says the hex code is the same then there must be some other factors at play. I dont really have the answer. I am keeping the original firmware just for contests. 73 John --- On Wed, 1/26/11, David Lear wrote: > From: David Lear > Subject: [Elecraft] APF > To: Elecraft@mailman.qth.net > Date: Wednesday, January 26, 2011, 11:27 AM > Did anything change with APF in the > latest release ? Seemed to perform > better before rev 2.45. Maybe I 'm just loosing my touch. > > 73 Dave Lear NE5DL > > __ > 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 This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[Elecraft] APF
Did anything change with APF in the latest release ? Seemed to perform better before rev 2.45. Maybe I 'm just loosing my touch. 73 Dave Lear NE5DL __ 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
Re: [Elecraft] APF effectiveness...
Bob, I would recommend you review the forum discussions on this subject last year from September thru November. This was discussed extensively. The K3 APF has been optimized. To reduce the sharp high Q audio sound would entail reducing the Q and flattening out the response. In essence reducing its peaking effectiveness. Yaesu had the best APF to date in their early FT1000D's. They modified the APF to broaden the response and lower the Q to please those that didn't like the sound of high Q audio peaking. This rendered the APF almost useless. They later came out with a mod to restore the APF to its original design. The Elecraft K3 APF is a derivative of this fantastic circuit and Elecraft is quite aware of the Yaesu APF history. Here is a response from Elecraft copied from an earlier discussion on this subject that was nearing its conclusion. We will not lower the Q of the existing APF function. We might add > > more Q selections -- someday. But we're not going to rush into further > > changes. Our priority right now is to correct some issues (mostly with > > SSB) and do a new beta release at the end of the week that includes APF. > > > > 73, > > Wayne > > N6KR > > There has been many glowing reports on the APF here in the forum. For me it is absolutely super to use now. It has added a new level to my 160 DXing. I am now able to copy and ambitiously seek new ones on 160 which were down in the noise and unreadable before. 73, Bob K6UJ __ 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] APF effectiveness...
I find the APF to be very effective when preceded by a relatively wider filter as suggested by K9ZTV, and offsetting the receive a little as mentioned by W6OPO. I generally use the 250 Hz crystal filter, followed by a DSP bandwidth between 200-300 Hz. I use a macro to turn on APF and FINE and offset the RIT by 20 Hz, then I tweak the APF shift and/or the RIT manually to peak the received signal. The purpose of the offset is to shift the signal frequency away from the ringing frequency. This works best for me at pitch settings near the low end of the K3's range. 73, Chuck Guenther NI0C W6OPO wrote: " I have had input from two Elecraft support fellows one of which was helpful. That being move the receiver off frequency (RIT) about 10Hz then adjust the APF center frequency to match. Some help - yes." K9ZTV wrote: " I've found that using the APF with the 400 filter (or wider) dialed-in provides less ringing than using APF with the 50 filter (DSP) dialed-in." __ 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
Re: [Elecraft] APF effectiveness...
I've found that using the APF with the 400 filter (or wider) dialed-in provides less ringing than using APF with the 50 filter (DSP) dialed-in. Either way, it's effectiveness is excellent, and that from a twelve-year FT-1000D owner. 73, Kent K9ZTV Jefferson City, MO __ 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
