APF (audio peaking filter) on the K3/K3S/KX3
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Re: APF (audio peaking filter) on the K3/K3S/KX3
 
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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 I somehow had a much better sense of band conditions, superseded now with internet propagation tools.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 <[hidden email]> 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:[hidden email]] 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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: APF (audio peaking filter) on the K3/K3S/KX3
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In reply to this post by wayne burdick
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, [hidden email] (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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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In reply to this post by Bob McGraw - K4TAX
Again and again, I have asked (privately) those reporting 'bad K3 audio' to furnish me with settings, measurements, recordings -- anything-- but I haven't ever received anything with which I could diagnose the problem.
Bad. Noisy. Fatiguing. These adjectives have been used continually to describe K3 audio. I believe you, I just don't know exactly what you're hearing. In the meantime, the analysis and recommendations that Ian, GM3SEK made here on 23 March are excellent and what I would consider required reading for anyone plagued with 'bad audio'. I must second all that he said. In conjunction with Ian's tips, if you're not in the habit of using Bob, K4TAX's technique [see below] to set your RF gain correctly, please consider doing so. I have come to believe that many hams may not want to turn down their RF Gain (or turn off their preamps, or turn on their attenuators) perhaps for fear of not hearing very weak signals? However, you can't hear anything below the atmospheric noise level... so once the receiver can hear the external noise floor, any further sensitivity or gain doesn't buy you anything and only increases the noisiness -- which is what many of the complainants complain about. I think it was about six years ago that I conducted a double-blind survey here on the reflector in which I presented hi-fi recordings of four different receivers-- including an unmodified K3 with the old DSP board-- and asked folks to identify the K3. I hypothesized that the 'noisy' and 'fatiguing' audio that many reported would make it easy to pick out the K3 from the group. [The other receivers in the test were an Omni VI, a K2, and a Ten Tec 1340.] The results were exactly the same as random chance guessing, and the loudest critics of the K3 at the time were conspicuous by not participating. I don't know why; this only served to increase my frustration. At the time (and up to this day) my K3 AGC parameters were almost exactly those recommended by GM3SEK. Anyway, please try all of these great techniques that have been presented in the past few weeks because I really believe they can help. Thanks for letting me beat this one to a pulp. [Now, if you want, you can beat me to a pulp privately instead of overloading the reflector.] Al W6LX > 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. The result is signal present and no noise. > 73 > Bob, K4TAX ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: [K3] Setting RF gain & AGC correctly
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The K3/K3S AGC settings have a lot to do with the apparent "noisy K3"
syndrome. IMHO, the K3 default AGC settings are not optimum. Look at my website www,w3fpr.com for information on how to customize your K3/K3S/KX3 AGC settings to optimum for your ambient noise and operating preferences. You will find a 'different receiver' when you adjust the AGC parameters. Pay particular attention to the method of evaluating the results. You must do the evaluation on pauses in the SSB communications or word/sentence breaks in CW. If you try to evaluate based on band noise alone, you will end up adjusting the parameters "backwards", and the result will be worse than when you started. 73, Don W3FPR On 4/8/2016 8:04 PM, Al Lorona wrote: > Again and again, I have asked (privately) those reporting 'bad K3 audio' to furnish me with settings, measurements, recordings -- anything-- but I haven't ever received anything with which I could diagnose the problem. > > Bad. Noisy. Fatiguing. These adjectives have been used continually to describe K3 audio. I believe you, I just don't know exactly what you're hearing. > > In the meantime, the analysis and recommendations that Ian, GM3SEK made here on 23 March are excellent and what I would consider required reading for anyone plagued with 'bad audio'. I must second all that he said. > > In conjunction with Ian's tips, if you're not in the habit of using Bob, K4TAX's technique [see below] to set your RF gain correctly, please consider doing so. I have come to believe that many hams may not want to turn down their RF Gain (or turn off their preamps, or turn on their attenuators) perhaps for fear of not hearing very weak signals? However, you can't hear anything below the atmospheric noise level... so once the receiver can hear the external noise floor, any further sensitivity or gain doesn't buy you anything and only increases the noisiness -- which is what many of the complainants complain about. > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: APF (audio peaking filter) on the K3/K3S/KX3
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In reply to this post by wayne burdick
When the APF was introduced the results were great, if I remember correctly.
Vk0EK is sometimes very weak here, so I played a lot with the settings, especially on the low bands. To my surprise the APF was worse than the NR. My first thought was that I forgot how to use it-I searched the archieves and so on...My personal conclusion is, as mentioned by others here ,that the earlier versions of the APF was better in the past or the NR is better now. 73,Chris-OE5CSP |
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In reply to this post by Don Wilhelm-4
To clarify what Don and Al have said, I don't take any position in the
"Bad Audio" discussion. I doubt if any of us truly understands what the other guy means by "bad audio" anyway. My comments were specifically about the so-called "pileup mush" that results from the poorly chosen default AGC settings; and also about the lack of follow-through from Elecraft on this topic. [What follows is a re-post of my earlier message referenced by Al (with minor edits). For clarity, I don't have any disagreement with the views of Don, Al or Barry N1EU. I'm out the door now for the GM DX Convention, so I won't be able to enter into detailed discussions for the next few days.] *************** The factory default AGC THReshold for the K3 and K3S is very, very low. Measurements by KE7X [1] have shown that the default setting of THR=5 corresponds to an AGC onset at less than S3, whereas competing rigs have a threshold of S7 or even higher. This very low AGC threshold is what allows the AGC to be activated by band noise. Elecraft's factory defaults of THR=5 and SLP=12 compress all signals above the AGC threshold into a very narrow range of audio output levels [see the measurements by KE7X]. This makes for comfortable broadcast-style listening - but there is price to be paid. The default settings greatly reduce the differences in the real-life strengths of incoming signals - important differences that DXers and contesters *need* to hear, in order to pick individual signals out of a pileup. Following complaints from DXers, DXpeditioners and contesters about this so-called "pileup mush", and following further series of measurements by KE7X, Elecraft eventually did increase the available range of AGC THReshold settings (the v4.51 firmware upgrade). Following the release of FW v4.51, the consensus within the [K3-contesting] Yahoo group about the most important settings for DXing and contesting has been as follows. * AGC THR: increase to at least 8 (from default = 5) and preferably to 12, and then take some time to become re-accustomed to the increased range of audio levels [2]. (Some users recommend as high as 14, if your ears can handle it.) * AGC SLP: decrease to 8 or even less (from default = 12). Lower SLP settings allow stronger signals to sound somewhat louder, and thus more realistic, but the range of variation will be partly determined by the THR setting already made; so always experiment with THR first, and with SLP afterwards. * AGC DCY = SOFT (not default=NOR). The User Manual claims that "The SOFT setting can reduce IMD caused by traditional AGC, and is especially useful in 'pileup' conditions, in some cases making it unnecessary to turn AGC off." The settings recommended above have essentially solved the problem of "pileup mush" for those who have tried them... but regrettably, Elecraft has done almost nothing to make DXers and contesters aware that such changes are possible. More than 3 years after the firmware release notes boasted that v4.51 "greatly improves signal clarity in pile-ups and other high-noise or dense-signal situations, especially with threshold set to 12 or higher", that information is *still* missing from the User Manual. There is also no information on how to create different 'profiles' of AGC settings for different types of users. Meanwhile, Elecraft's factory AGC defaults remain exactly as they were, still optimized apparently for comfortable 'listening', while many DXers and contesters remain unaware that their K3/K3S could actually be *so* much better. [1] http://www.ke7x.com/home/miscellaneous-k3-information [2] It is important to give any increased AGC THReshold setting an extended trial. To anyone accustomed to an artificially restricted range of audio signal levels, a higher setting will initially sound quite 'aggressive' - even though the new setting is much closer to real life. ************ 73 from Ian GM3SEK 73 from Ian GM3SEK >-----Original Message----- >From: Elecraft [mailto:[hidden email]] On Behalf Of >Don Wilhelm >Sent: 09 April 2016 01:30 >To: [hidden email] >Subject: Re: [Elecraft] [K3] Setting RF gain & AGC correctly > >The K3/K3S AGC settings have a lot to do with the apparent "noisy K3" >syndrome. >IMHO, the K3 default AGC settings are not optimum. >Look at my website www,w3fpr.com for information on how to customize >your K3/K3S/KX3 AGC settings to optimum for your ambient noise and >operating preferences. You will find a 'different receiver' when you >adjust the AGC parameters. > >Pay particular attention to the method of evaluating the results. You >must do the evaluation on pauses in the SSB communications or >word/sentence breaks in CW. If you try to evaluate based on band noise >alone, you will end up adjusting the parameters "backwards", and the >result will be worse than when you started. > >73, >Don W3FPR > >On 4/8/2016 8:04 PM, Al Lorona wrote: >> Again and again, I have asked (privately) those reporting 'bad K3 >furnish me with settings, measurements, recordings -- anything-- but I >haven't ever received anything with which I could diagnose the problem. >> >> Bad. Noisy. Fatiguing. These adjectives have been used continually to >describe K3 audio. I believe you, I just don't know exactly what you're >hearing. >> >> In the meantime, the analysis and recommendations that Ian, GM3SEK >made here on 23 March are excellent and what I would consider required >reading for anyone plagued with 'bad audio'. I must second all that he >> >> In conjunction with Ian's tips, if you're not in the habit of using Bob, >K4TAX's technique [see below] to set your RF gain correctly, please consider >doing so. I have come to believe that many hams may not want to turn >down their RF Gain (or turn off their preamps, or turn on their attenuators) >perhaps for fear of not hearing very weak signals? However, you can't hear >anything below the atmospheric noise level... so once the receiver can hear >the external noise floor, any further sensitivity or gain doesn't buy you >anything and only increases the noisiness -- which is what many of the >complainants complain about. >> > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: [K3] Setting RF gain & AGC correctly
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So... Elecraft almost completely rewrites the AGC support in their firmware... and that's a lack of follow-through? lots of hi hi's and smileys here..
but seriously, I totally agree that the wrong AGC settings can make the APF almost unusable. I personally have found that it works the best with the AGC simply turned off. The cost is having to "ride" the volume control a little bit in the QSB, but it becomes a razor blade without the AGC enabled at all on a weak sig. As for the AGC settings, after experimentation I've ended up with both SLP and THR set to 10 on my K3 and K3S. That gives the best balance for my ears between compression and "pumping" kinds of effects on fast AGC. YMMV. As for "noisy K3", I'm not sure what that refers to. I've complained about the quality of the audio, essentially the freq. response, in the past but the K3 RX is probably the quietest on the market. Mine and my K3S both are virtually silent out on my /p ops, out where I'm far away from man-made industrial noise sources. Even before I upgraded the synthesizer, the K3 was one of the quietest RX's I've ever used. 73, LS W5QD
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Re: [K3] Setting RF gain & AGC correctly
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In reply to this post by gm3sek
I totally understand what your talking about but you have to be aware of
the fur ball that happened on this list when the K3 was introduced. "It doesn't sound like my (insert favorite Japanese Radio here)". There were people running around on different message boards claiming the K3's audio was terrible, even though it was configurable with said AGC settings and probably the best receiver any of them had ever heard. So what is a company to do, make the radio "sound better" out of the box or let the nattering nabobs of negativism continue to slander the rig? They made the necessary anti-mush firmware changes and left the default alone. Pretty good middle of the road solution. DXer's and contestors are supposed to be our best and brightest, not counting some recent high profile DXpeditions (that's another thread), but can't keep on top of firmware changes and experiment with AGC settings? We haven't ALL become appliance operators needing our hands held have we? I'll bet the 4.51 changes were all over contesting.com within 10 minutes of being released. The changes were discussed on this list until the horse resembled glue. Claiming nobody knows/knew about them is silly. On 4/9/2016 2:44 AM, Ian White wrote: > To clarify what Don and Al have said, I don't take any position in the > "Bad Audio" discussion. I doubt if any of us truly understands what the > other guy means by "bad audio" anyway. > > My comments were specifically about the so-called "pileup mush" that > results from the poorly chosen default AGC settings; and also about the > lack of follow-through from Elecraft on this topic. > > [What follows is a re-post of my earlier message referenced by Al (with > minor edits). For clarity, I don't have any disagreement with the views > of Don, Al or Barry N1EU. > > I'm out the door now for the GM DX Convention, so I won't be able to > enter into detailed discussions for the next few days.] > > *************** > > The factory default AGC THReshold for the K3 and K3S is very, very low. > Measurements by KE7X [1] have shown that the default setting of THR=5 > corresponds to an AGC onset at less than S3, whereas competing rigs have > a threshold of S7 or even higher. This very low AGC threshold is what > allows the AGC to be activated by band noise. > > Elecraft's factory defaults of THR=5 and SLP=12 compress all signals > above the AGC threshold into a very narrow range of audio output levels > [see the measurements by KE7X]. This makes for comfortable > broadcast-style listening - but there is price to be paid. The default > settings greatly reduce the differences in the real-life strengths of > incoming signals - important differences that DXers and contesters > *need* to hear, in order to pick individual signals out of a pileup. > > Following complaints from DXers, DXpeditioners and contesters about this > so-called "pileup mush", and following further series of measurements by > KE7X, Elecraft eventually did increase the available range of AGC > THReshold settings (the v4.51 firmware upgrade). > > Following the release of FW v4.51, the consensus within the > [K3-contesting] Yahoo group about the most important settings for DXing > and contesting has been as follows. > > * AGC THR: increase to at least 8 (from default = 5) and preferably to > 12, and then take some time to become re-accustomed to the increased > range of audio levels [2]. (Some users recommend as high as 14, if your > ears can handle it.) > > * AGC SLP: decrease to 8 or even less (from default = 12). Lower SLP > settings allow stronger signals to sound somewhat louder, and thus more > realistic, but the range of variation will be partly determined by the > THR setting already made; so always experiment with THR first, and with > SLP afterwards. > > * AGC DCY = SOFT (not default=NOR). The User Manual claims that "The > SOFT setting can reduce IMD caused by traditional AGC, and is especially > useful in 'pileup' conditions, in some cases making it unnecessary to > turn AGC off." > > The settings recommended above have essentially solved the problem of > "pileup mush" for those who have tried them... but regrettably, Elecraft > has done almost nothing to make DXers and contesters aware that such > changes are possible. > > More than 3 years after the firmware release notes boasted that v4.51 > "greatly improves signal clarity in pile-ups and other high-noise or > dense-signal situations, especially with threshold set to 12 or higher", > that information is *still* missing from the User Manual. There is also > no information on how to create different 'profiles' of AGC settings for > different types of users. > > Meanwhile, Elecraft's factory AGC defaults remain exactly as they were, > still optimized apparently for comfortable 'listening', while many DXers > and contesters remain unaware that their K3/K3S could actually be *so* > much better. > > > > [1] http://www.ke7x.com/home/miscellaneous-k3-information > > [2] It is important to give any increased AGC THReshold setting an > extended trial. To anyone accustomed to an artificially restricted range > of audio signal levels, a higher setting will initially sound quite > 'aggressive' - even though the new setting is much closer to real life. > > ************ > > 73 from Ian GM3SEK > > -- R. Kevin Stover AC0H ARRL FISTS #11993 SKCC #215 NAQCC #3441 --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: [K3] Setting RF gain & AGC correctly
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Agree, even I figured out how to twiddle the AGC settings once I found them. They're not hard to find, just scroll until you see something that starts with "AGC..." hi hi. If I can do it, anyone can.
As for the defaults, IMO, the K3/K3S AGC is plenty good enough to live with them for quite a while even if you _don't_ manage to find the configuration settings somehow. In fact, about all you'll notice is a slightly strange occasional "pumping" action on AGC - S on CW sigs with a lot of QSB, which may or may not make you scratch your head and send you to the manual. On voice it might be a little fatiguing on AGC - F after a while; again that may send you to the manual to look for settings or it may not. As for not sounding like your favorite other rig, you say that like it's a bad thing hi hi. I'd rather not hear the squeal of the tuner-upper 1kc away blowing through the filters at all, no matter how nice the audio of it may be. That's what I get with my K's regardless of any other issues my hearing may have.... 73, LS W5QD |
Re: [K3] Setting RF gain & AGC correctly
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In reply to this post by gm3sek
Note that to change some of the AGC settings you must have Tech
MD ON. I tried these settings and went back to the stock settings. I think the reasons were: I don't run pileups. I am mostly a S&P contester, and always in the pileup rather than working it for DX. (Just how many people need Santa Clara County CA?), so most of the improvements don't affect me very much. When I'm listening to weak DX, the higher SLP keeps the occasional person who forgets to go into split mode (and the up police) from blasting out my eardrums. My normal background noise on 20M is about S2. (It's about S5 on 160M.) I think this means that I'm not getting AGC from the normal background. BTW, I don't know why my noise levels are so low living in suburbia. I always seem to be a couple of S units weaker than others I hear giving honest signal reports. In any case, I have enough sensitivity to get the band noise, and I can certainly hear a lot of stations which can't hear me. When I run digital modes, I don't have to ride the RF gain to keep the audio signal to the computer below overload, a nice convenience. I will have to try turning AGC off when using the Audio Frequency Peaking feature. With AGC on, it only seems to do a little compared with 50 or 100 HZ on the DSP filter. The DSP filter technique helps suppress slightly off frequency strong signals better too. 73 Bill AE6JV On 4/9/16 at 12:44 AM, [hidden email] (Ian White) wrote: >Following the release of FW v4.51, the consensus within the >[K3-contesting] Yahoo group about the most important settings for DXing >and contesting has been as follows. >* AGC THR: increase to at least 8 (from default = 5) and preferably to >12, and then take some time to become re-accustomed to the increased >range of audio levels [2]. (Some users recommend as high as 14, if your >ears can handle it.) > >* AGC SLP: decrease to 8 or even less (from default = 12). Lower SLP >settings allow stronger signals to sound somewhat louder, and thus more >realistic, but the range of variation will be partly determined by the >THR setting already made; so always experiment with THR first, and with >SLP afterwards. >* AGC DCY = SOFT (not default=NOR). The User Manual claims that "The >SOFT setting can reduce IMD caused by traditional AGC, and is especially >useful in 'pileup' conditions, in some cases making it unnecessary to >turn AGC off." ------------------------------------------------------------------------ Bill Frantz |"Insofar as the propositions of mathematics refer to 408-356-8506 | reality, they are not certain; and insofar they are www.pwpconsult.com | certain, they do not refer to reality.” -- Einstein ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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I left all of Bill's post below for context. Full disclosure - 95% CW
My experience parallels Bill's for much the same reasons. My K3 [#642] has had two EEINIT's, and I haven't changed the AGC settings since the second one, 4 or 5 years ago. The K3 AGC parameters are many and have interacting effects. When playing with them, often I was unable to discern a difference between choices, even going very slowly and operating for awhile between changes. I find the APF to be useful with weak signals of course, but also with moderate signals in deep QSB ... with APF I don't lose it completely even though it went to near ESP levels briefly. I have spent some listening time to SM, LA, OH, and the like during auroral events, with rapid, deep QSB, and with AGC off and riding the RF Gain. Given that the propagation under these conditions is essentially a chaotic function, I may ... or have just imagined ... a very subtle improvement over just running RF at max with AGC on. I had to max the AF GAIN on my SX-28 and ride the RF of course, now many years later, I find the stock K3 settings to be close to very good for me. Grizzled Old Engineer advice to an aspiring new engineer [me]: "The fewer the knobs, the less problems from the users." 73, Fred K6DGW - Northern California Contest Club - CU in the Cal QSO Party 1-2 Oct 2016 - www.cqp.org On 4/9/2016 4:32 PM, Bill Frantz wrote: > Note that to change some of the AGC settings you must have Tech MD ON. > > I tried these settings and went back to the stock settings. I think the > reasons were: > > I don't run pileups. I am mostly a S&P contester, and always in the > pileup rather than working it for DX. (Just how many people need Santa > Clara County CA?), so most of the improvements don't affect me very much. > > When I'm listening to weak DX, the higher SLP keeps the occasional > person who forgets to go into split mode (and the up police) from > blasting out my eardrums. > > My normal background noise on 20M is about S2. (It's about S5 on 160M.) > I think this means that I'm not getting AGC from the normal background. > BTW, I don't know why my noise levels are so low living in suburbia. I > always seem to be a couple of S units weaker than others I hear giving > honest signal reports. In any case, I have enough sensitivity to get the > band noise, and I can certainly hear a lot of stations which can't hear me. > > When I run digital modes, I don't have to ride the RF gain to keep the > audio signal to the computer below overload, a nice convenience. > > I will have to try turning AGC off when using the Audio Frequency > Peaking feature. With AGC on, it only seems to do a little compared with > 50 or 100 HZ on the DSP filter. The DSP filter technique helps suppress > slightly off frequency strong signals better too. > > 73 Bill AE6JV ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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