RX architecture
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Yes,
9MHz down-conversion was standard when I homebrewed SS transceivers in 1960-70. But architecture is also part of its components. We do not use simple VFO any more, and much has been made to make injection signal pure again. Mixers are much better (we had hot-carrier diode quads). IF DSP is new in down-conversion scheme. And all is for our good. Enjoy and smile! Benny OH9NB ______________________________________________________________ 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 |
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Hi I was so impressed by the original K3 APF firmware. Why is it so lack luster in the current beta? I have read all the posts that there is no difference, my ears tell me different? When I used the APF in its original release on 160m and 80 meters it just blew me away to mars and back. Now I might as well not have it on! The signals dont "pop"out of the noise like they use too. I might have to have my ears cleaned and checked for wax or something. I am mystified especially when Lyle says that there is no difference in the firmware. The K3's APF in the current beta behaves much like the one in my Icom radios and they are very ineffective in the Icom radios. I have shifted back to the old beta 4 times and the results are better for the old APF and it wins hands down. I will keep the old beta just for contests, its just too good not to use. 73 John ______________________________________________________________ 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 |
Re: K3:New APF what happened?
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John, did you check in the CONFIG menu to make sure APF is turned on?
73, Pete N4ZR The World Contest Station Database, updated daily at www.conteststations.com The Reverse Beacon Network at http://reversebeacon.net, blog at reversebeacon.blogspot.com, spots at telnet.reversebeacon.net, port 7000 On 11/17/2010 3:16 AM, juergen wrote: > Hi > > I was so impressed by the original K3 APF firmware. Why is it so lack luster in the current beta? > > I have read all the posts that there is no difference, my ears tell me different? > > When I used the APF in its original release on 160m and 80 meters it just blew me away to mars and back. Now I might as well not have it on! The signals dont "pop"out of the noise like they use too. > > I might have to have my ears cleaned and checked for wax or something. > I am mystified especially when Lyle says that there is no difference in the firmware. > > > The K3's APF in the current beta behaves much like the one in my Icom radios and they are very ineffective in the Icom radios. > > I have shifted back to the old beta 4 times and the results are better for the old APF and it wins hands down. I will keep the old beta just for contests, its just too good not to use. > > 73 > John > > > > > > > ______________________________________________________________ > 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 > > 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 |
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Well,well,well,lets put a couple of cents here.Last night at midnight when the XYL went to sleep and it was very quite I finally installed the Beta version 4.22 on my K3 and after few minutes when it ended up,move the dial to the lower end of 40M band and there was a station from Senegal,my dipole antenna is not too high,just 20 feet over the ground and his signal was only 559 and afer narrowing the DSP to 500Hz still heard him weak and little noisy BUT when I pressed for more than a second the XFIL/DUAL PB key to enable the APF WOW !! I almost fell off my chair,that Senegal station was so loud and clean as a local station,signal was still a S5 but the received audio was so clear and loud that look like a 599 station.I am very impressed with this new filter and to be honest the last Icom radio I owned was the 756ProIII and that guy could never do this so well.
Again my claps go to Elecraft for having improved further more our K3's. Thanks Hector AD4C K3 # 2192 "If you see a driver handling a cell phone on her/his hands while driving,do please stay away from that vehicle,its a moving bomb.Your life is at danger.Keep yourself and your family alive" --- On Wed, 11/17/10, Pete Smith <[hidden email]> wrote: From: Pete Smith <[hidden email]> Subject: Re: [Elecraft] K3:New APF what happened? To: [hidden email] Date: Wednesday, November 17, 2010, 12:41 PM John, did you check in the CONFIG menu to make sure APF is turned on? 73, Pete N4ZR The World Contest Station Database, updated daily at www.conteststations.com The Reverse Beacon Network at http://reversebeacon.net, blog at reversebeacon.blogspot.com, spots at telnet.reversebeacon.net, port 7000 On 11/17/2010 3:16 AM, juergen wrote: > Hi > > I was so impressed by the original K3 APF firmware. Why is it so lack luster in the current beta? > > I have read all the posts that there is no difference, my ears tell me different? > > When I used the APF in its original release on 160m and 80 meters it just blew me away to mars and back. Now I might as well not have it on! The signals dont "pop"out of the noise like they use too. > > I might have to have my ears cleaned and checked for wax or something. > I am mystified especially when Lyle says that there is no difference in the firmware. > > > The K3's APF in the current beta behaves much like the one in my Icom radios and they are very ineffective in the Icom radios. > > I have shifted back to the old beta 4 times and the results are better for the old APF and it wins hands down. I will keep the old beta just for contests, its just too good not to use. > > 73 > John > > > > > > > ______________________________________________________________ > 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 > > 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 ______________________________________________________________ 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 |
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In reply to this post by juergen piezo
John,
Maybe the impact of the APF is a moving target influenced by the band conditions at the time? Yesterday morning 160M was very quiet. I could not hear the VK6 without the APF. When I turned on the APF the VK6 popped out of the band noise and was easily copyable. There was no hint of ringing even with the bandwidth down to 50HZ. Last night as usual in the evenings here 160M was noisy. When I turned on the APF it still did its magic. But there was almost a trace of "ringing". I need to play more with it to see if it is a definite pattern comparing between quiet and noisy band conditions. Also I think I should install 4.14 in my second K3 to compare the two versions to see if I hear the difference you are hearing 73, N2TK, Tony K3 #311 K3 #1435 -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of juergen Sent: Wednesday, November 17, 2010 3:17 AM To: [hidden email] Subject: [Elecraft] K3:New APF what happened? Hi I was so impressed by the original K3 APF firmware. Why is it so lack luster in the current beta? I have read all the posts that there is no difference, my ears tell me different? When I used the APF in its original release on 160m and 80 meters it just blew me away to mars and back. Now I might as well not have it on! The signals dont "pop"out of the noise like they use too. I might have to have my ears cleaned and checked for wax or something. I am mystified especially when Lyle says that there is no difference in the firmware. The K3's APF in the current beta behaves much like the one in my Icom radios and they are very ineffective in the Icom radios. I have shifted back to the old beta 4 times and the results are better for the old APF and it wins hands down. I will keep the old beta just for contests, its just too good not to use. 73 John ______________________________________________________________ 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 ______________________________________________________________ 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 |
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Let me state right up front that my CW is bad, mostly because of an ear
problem. But my decoder software allows me to operate CW fairly well. With that said -- Unfortunately, I stayed away from the previous beta version and sat back to wait for this new version. Now, I don't have a comparison. I was expecting something more than I got. I have yet to find a signal that really "pops" out at me. Yes, it helps on some signals but not on others. In fact, due to the "ringing" or hollow sound, the weak signal is better copy with normal operations. If have I/II so I can switch back and forth quickly. I use the 400 narrow filter. NR,NB, etc off. Anybody have any suggestions that can bring this station up to what others are reporting that they experience? de K2GN - Larry - http://k2gn.com K3 S/N - 3278 P3 S/N - 51 FW - 4.22 ______________________________________________________________ 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 |
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In reply to this post by N2TK
Ringing is a function of how much impulse noise (i.e. lightning induced, electric fencer "ticks", key clicks, etc) hits the filter. No impulse noise = no ringing, lots of impulse noise = continuous ringing. As you said, yesterday morning 160m was stone quiet and the background noise was non-impulsive or white noise. Last night a strong cold front moved across the Southeastern states which had lightning associated with the front. The lightning strikes created impulse noise which caused the filter to ring more than in the morning. This effect is present in any narrow filter, whether analog or digital, and there's really not much that can be done to avoid it. Reducing AF Gain is about the only solution to attenuate the continuous ringing sound but that also attenuates the signal you're trying to hear. 73, Bill |
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In reply to this post by juergen piezo
I am not too impressed as the hollow ringing sounds like a regenerative
receiver going into oscillation. It can help you distinguish the dits but it isn't pretty listening. I think the manuals need to catch up with the betas so I can get more comfortable with the adjustments. Buck k4ia k3#101 In a message dated 11/17/2010 9:16:22 A.M. Eastern Standard Time, [hidden email] writes: The new APF continues to please this CW operator. Like others, I find it works better in some situations than others. But I would not have been able to copy and work RI1FJ (Franz Josef Land) on 160m the morning of November 8 without this new tool. A few suggestions for using it: 1. Make sure the CW signal is centered in the passband at your selected pitch, before engaging APF. For very weak signals, I always rely on my ear to match the pitch, rather than using the K3 SPOT or CWT features. 2. After turning APF on, use the APF SHIFT (now 5 Hz resolution) and/or FINE tuning (1 Hz resolution) to peak the signal. 3. I've mentioned this before, but I use a Macro to turn on APF,FINE, and RIT with one button push (and another Macro to turn off all these functions). 73, Chuck NI0C K3 s/n 1061 Larry, K2GN, wrote: "Yes, it helps on some signals but not on others. In fact, due to the "ringing" or hollow sound, the weak signal is better copy with normal operations. If have I/II so I can switch back and forth quickly. I use the 400 narrow filter. NR,NB, etc off. Anybody have any suggestions that can bring this station up to what others are reporting that they experience?" ______________________________________________________________ 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 ______________________________________________________________ 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 |
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It can be proven mathematically that the speed at which information can be sent decreases
as the bandwidth of the channel decreases. One of the ways of increasing the signal/noise ratio of a channel is by narrowing it, but there's a trade-off -- you have to slow down the data rate. In our case, this means that the ringing will cause the dits to run together unless you ask the guy to QRS! If the s/n ratio is good with a wider bandwidth, then you don't need the APF. Turning it on will reduce the top speed that can be used. There's no free lunch! On 11/17/2010 8:31 AM, [hidden email] wrote: > I am not too impressed as the hollow ringing sounds like a regenerative > receiver going into oscillation. It can help you distinguish the dits but it > isn't pretty listening. I think the manuals need to catch up with the > betas so I can get more comfortable with the adjustments. > > Buck > > k4ia > k3#101 -- Vic, K2VCO Fresno CA http://www.qsl.net/k2vco/ ______________________________________________________________ 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 |
Re: K3:New APF what happened?
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In reply to this post by Bill W4ZV
Very good summary of the technical facts, Bill.
It's IMPULSE noise, everybody, not white noise or pink noise or any other kind of noise. Impulse noise is characterized by a very rapid transient rise-time producing a large nearly instantaneous spike in amplitude. It's literally the electrical equivalent of striking a bell sharply, as opposed to rubbing it. The other thing that can make this feature seem magical (in the absence of excessive ringing) is having it properly tuned, and by "properly" I mean within a few Hertz. The K3's CWT/SPOT capability is good, but it's often not good enough for this degree of accuracy. Mine usually tunes to within +/- 10 Hz, but that's not always close enough for the APF to work at its best. The signal needs to be fine-tuned by ear, IMO, against the sidetone PITCH frequency. Most people can hear the difference between two tones down to 1 Hz or less. (BUT, some people CAN'T. It's a brain thing. Your brain can either do this or it can't. My XYL couldn't do this if her life depended on it, as she is completely tone-deaf.) So maybe we can agree that there are a lot of variables at work here that we can't control for. I thought at first that the current release was "less ringy" than the earlier release; I was fooled by a difference in band noise. Since then, I've seen the APF feature behave quite differently on different bands at different times. So, if it makes it easier to copy a given signal, use it, and if it doesn't, leave it turned off. It's a tool. All tools are not appropriate for all jobs all the time. You have to choose your tools and when to use them. Bill W5WVO -----Original Message----- From: Bill W4ZV Sent: Wednesday, November 17, 2010 15:35 To: [hidden email] Subject: Re: [Elecraft] K3:New APF what happened? N2TK wrote: > > John, > Maybe the impact of the APF is a moving target influenced by the band > conditions at the time? > Yesterday morning 160M was very quiet. I could not hear the VK6 without > the > APF. When I turned on the APF the VK6 popped out of the band noise and was > easily copyable. There was no hint of ringing even with the bandwidth down > to 50HZ. > > Last night as usual in the evenings here 160M was noisy. When I turned on > the APF it still did its magic. But there was almost a trace of "ringing". > > I need to play more with it to see if it is a definite pattern comparing > between quiet and noisy band conditions. > Ringing is a function of how much impulse noise (i.e. lightning induced, electric fencer "ticks", key clicks, etc) hits the filter. No impulse noise = no ringing, lots of impulse noise = continuous ringing. As you said, yesterday morning 160m was stone quiet and the background noise was non-impulsive or white noise. Last night a strong cold front moved across the Southeastern states which had lightning associated with the front. The lightning strikes created impulse noise which caused the filter to ring more than in the morning. This effect is present in any narrow filter, whether analog or digital, and there's really not much that can be done to avoid it. Reducing AF Gain is about the only solution to attenuate the continuous ringing sound but that also attenuates the signal you're trying to hear. 73, Bill -- View this message in context: http://elecraft.365791.n2.nabble.com/RX-architecture-tp5746603p5748164.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:[hidden email] 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] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by Bill W4ZV
On 11/17/2010 7:35 AM, Bill W4ZV wrote:
> Reducing AF Gain is about the only solution to attenuate the continuous > ringing sound but that also attenuates the signal you're trying to hear. Reducing RF gain is also a big help. 73, Jim K9YC ______________________________________________________________ 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 |
Re: K3:New APF what happened?
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In reply to this post by Bill VanAlstyne W5WVO
Bill:
Nice job. I figured all along it was either due to a brain problem or being female. Steve N4LQ ----- Original Message ----- From: "Bill VanAlstyne W5WVO" <[hidden email]> To: "Bill W4ZV" <[hidden email]>; <[hidden email]> Sent: Wednesday, November 17, 2010 2:45 PM Subject: Re: [Elecraft] K3:New APF what happened? > Very good summary of the technical facts, Bill. > > It's IMPULSE noise, everybody, not white noise or pink noise or any other > kind of noise. Impulse noise is characterized by a very rapid transient > rise-time producing a large nearly instantaneous spike in amplitude. It's > literally the electrical equivalent of striking a bell sharply, as opposed > to rubbing it. > > The other thing that can make this feature seem magical (in the absence of > excessive ringing) is having it properly tuned, and by "properly" I mean > within a few Hertz. The K3's CWT/SPOT capability is good, but it's often > not > good enough for this degree of accuracy. Mine usually tunes to within +/- > 10 > Hz, but that's not always close enough for the APF to work at its best. > The > signal needs to be fine-tuned by ear, IMO, against the sidetone PITCH > frequency. Most people can hear the difference between two tones down to 1 > Hz or less. (BUT, some people CAN'T. It's a brain thing. Your brain can > either do this or it can't. My XYL couldn't do this if her life depended > on > it, as she is completely tone-deaf.) > > So maybe we can agree that there are a lot of variables at work here that > we > can't control for. I thought at first that the current release was "less > ringy" than the earlier release; I was fooled by a difference in band > noise. > Since then, I've seen the APF feature behave quite differently on > different > bands at different times. So, if it makes it easier to copy a given > signal, > use it, and if it doesn't, leave it turned off. It's a tool. All tools are > not appropriate for all jobs all the time. You have to choose your tools > and > when to use them. > > Bill W5WVO > > > > -----Original Message----- > From: Bill W4ZV > Sent: Wednesday, November 17, 2010 15:35 > To: [hidden email] > Subject: Re: [Elecraft] K3:New APF what happened? > > > > N2TK wrote: >> >> John, >> Maybe the impact of the APF is a moving target influenced by the band >> conditions at the time? >> Yesterday morning 160M was very quiet. I could not hear the VK6 without >> the >> APF. When I turned on the APF the VK6 popped out of the band noise and >> was >> easily copyable. There was no hint of ringing even with the bandwidth >> down >> to 50HZ. >> >> Last night as usual in the evenings here 160M was noisy. When I turned on >> the APF it still did its magic. But there was almost a trace of >> "ringing". >> >> I need to play more with it to see if it is a definite pattern comparing >> between quiet and noisy band conditions. >> > > Ringing is a function of how much impulse noise (i.e. lightning induced, > electric fencer "ticks", key clicks, etc) hits the filter. No impulse > noise > = no ringing, lots of impulse noise = continuous ringing. As you said, > yesterday morning 160m was stone quiet and the background noise was > non-impulsive or white noise. Last night a strong cold front moved across > the Southeastern states which had lightning associated with the front. > The > lightning strikes created impulse noise which caused the filter to ring > more > than in the morning. This effect is present in any narrow filter, whether > analog or digital, and there's really not much that can be done to avoid > it. > Reducing AF Gain is about the only solution to attenuate the continuous > ringing sound but that also attenuates the signal you're trying to hear. > > 73, Bill > -- > View this message in context: > http://elecraft.365791.n2.nabble.com/RX-architecture-tp5746603p5748164.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:[hidden email] > > 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] > > 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] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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