Interesting comment Guy...I assume that must be based on Bell Labs research. I use AFX DELAY 5 100% of the time and diversity 99.999% of the time. I wonder if that could explain why I've never experienced the fatigue some complain about? 73, Bill |
Really not surprised you use AFX and diversity all the time.
Lot of people all over the place have done that mono recording comparison. We did it in college. My labor assignment at Berea College was the Audio/Visual department. We were incessantly messing around with stuff when not running a setup. What was interesting was that two separate mikes and stereo weren't much better until they were well separated. Stuff I read somewhere much later (Discover, Scientific American, Science News ??) was explaining how the shape of the ears contributed to our sense of direction. Miniature mikes for affordable prices were what got all that going. I don't experience the fatigue either. But then again I had the summer 80m Klingon pain-stick training. :>) And I have been known to operate the entire evening 40m EU opening with AGC off on an MP. I checked. I do have the AFX on all the time. But can't remember when I turned it on. I was using the "bin" setting. It seems more "centered" on speakers. Put on the QC15 headsets and delay 5 has a better "spread". On the speakers delay 5 seems way left. I wonder what that is about. 73, Guy. On Wed, Feb 10, 2010 at 3:23 PM, Bill W4ZV <[hidden email]> wrote: > > > Guy, K2AV wrote: >> >> In a crowded room our brain neatly interprets stereophonic sound to >> separate out a single spatially diverse conversation from dozens of >> others at essentially the same level. In research using a monophonic >> recording of the multiple conversations from a single microphone in >> the same room, very few can discern individual conversations, and most >> find any length of listening to the recording irritating and tiring. >> > > Interesting comment Guy...I assume that must be based on Bell Labs research. > I use AFX DELAY 5 100% of the time and diversity 99.999% of the time. I > wonder if that could explain why I've never experienced the fatigue some > complain about? > > 73, Bill > > -- > View this message in context: http://n2.nabble.com/K3-in-a-cw-pileup-needs-work-tp4523884p4550559.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:[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 |
In reply to this post by Don Wilhelm-4
Don, > Can you elaborate your reasons for this suggestion. Adding attenuation before the first active stage (amplifier) always reduces noise figure because that's where the S/N ratio is determined provided the first stage has enough gain to override the noise of the next stage. > I had come to believe that the best situation is to place > attenuation before the first mixer to give the greatest > amount of dynamic range (headroom). That assumes any IMD is produced only in the first mixer. In the K3, the limiting factor is almost certainly later in the chain because of the very good IMD performance of the KR (first) mixer. Without specific analysis, the weakest link is probably the ADC followed by the second mixer. If it was the first mixer, narrowing the roofing filter would not improve the dynamic range. That's why I would do two stages of gain reduction - 10 dB in the 30 kHz IF followed by 6 dB in the 8.125 MHz IF, if needed. A designer always wants to make sure any amplifier gain is sufficient for the noise figure of the succeeding stage but low enough to avoid overload down the line. 73, ... Joe, W4TV > -----Original Message----- > From: Don Wilhelm [mailto:[hidden email]] > Sent: Wednesday, February 10, 2010 1:06 AM > To: Joe Subich, W4TV > Cc: [hidden email] > Subject: Re: [Elecraft] K3 DSP AGC Question > > > Joe, > > Can you elaborate your reasons for this suggestion. I had come to > believe that the best situation is to place attenuation > before the first > mixer to give the greatest amount of dynamic range (headroom). > > Yes, I agree that the AGC Threshold could be raised in the K3 > and would > be beneficial. I have felt the default of 005 was too low. > > 73, > Don W3FPR > > Joe Subich, W4TV wrote: > > Perhaps one should get the ambient well down in the ADC operating > > range but killing gain (adding loss) before the first mixer and > > the roofing filter is not the way to do it. If you want to > > better align the dynamic range of the receiver (or specifically > > the ADC) to conditions, the attenuation should come in the > > IF - preferably divided between the first IF and 2nd IF. > > > > However, there would still be no apparent reason that the K3 > > should not be capable of sustaining an AGC threshold at least > > 10 db higher than currently set with AGC THR = 008 whether > > that be reached with preamp on, preamp off or attenuator on. > > > > 73, > > > > ... Joe, W4TV > > > > > > > > > >> -----Original Message----- > >> From: [hidden email] > >> [mailto:[hidden email]] On Behalf Of Guy > >> Olinger K2AV > >> Sent: Monday, February 08, 2010 1:49 PM > >> To: [hidden email] > >> Cc: [hidden email] > >> Subject: Re: [Elecraft] K3 DSP AGC Question > >> > >> > >> It may be a dance, but hopefully careful intelligent musing > >> over the matter is convincing people that they should get the > >> ambient well down in the analog-to-digital converter (ADC) > >> operating range. If they do, a -99 threshold is a -109 > >> threshold, and further backing off RF gain can make it a -119 > >> or -129 threshold as far as the ADC is concerned, and > >> headroom is being used for what headroom should be used for. > >> > >> One thing for sure, there has not been a good-enough > >> presentation of what is going on, and people really don't > >> seem to get it. For something that is plain indisputable > >> physics, people are still running PRE and max RFgain on 80 > >> with fast AGC, and are honestly dismayed and confused about > >> the inevitable outcome, incorrectly blaming the rig for being > >> natively noisy, no-work NR and NB, filter "ringing", unable > >> to pull signals out of noise, and more. > >> > >> Maybe the variable gain by band in the MP (with a menu > >> override) was really a better strategy for a default. This > >> same issue dogged Orion owners, and by the chatter a lot of > >> them never understood either. > >> > >> There IS something entirely separate with the headphone audio > >> and HI-Z headsets, high volume levels, maybe a sharp > >> saturation point, and mush, just haven't nailed it yet. > >> > >> 73, Guy. > >> > >> On Mon, Feb 8, 2010 at 12:01 PM, Joe Subich, W4TV > >> <[hidden email]> wrote: > >> > >>> > >>>> Likely? I don't know. > >>>> > >>> Likely is a better choice since raising the AGC threshold > >>> > >> seems to be > >> > >>> the primary goal of much of the "PRE/ATT/RF Gain dance" we've seen > >>> recently. > >>> > >>> The hardware AGC (HAGC) would seem to provide an ultimate limit on > >>> level to the ADC - unless the ADC can't handle the > >>> > >> transient peaks - > >> > >>> so a higher threshold for the DSP derived AGC would be > >>> > >> helpful in many > >> > >>> ways. > >>> > >>> 73, > >>> > >>> ... Joe, W4TV > >>> > >>> > >>> > >>> > >>> > >>>> -----Original Message----- > >>>> From: [hidden email] > >>>> [mailto:[hidden email]] On Behalf Of > Lyle Johnson > >>>> Sent: Monday, February 08, 2010 11:24 AM > >>>> To: [hidden email] > >>>> Subject: Re: [Elecraft] K3 DSP AGC Question > >>>> > >>>> > >>>> Hello Joe! > >>>> > >>>>> Assuming that the threshold values have not changed in a > >>>>> > >> major way > >> > >>>>> since Jack's measurements, would it be possible to > >>>>> > >> extend the range > >> > >>>>> of threshold values - say to AGC THR=016 at about -80dBm > >>>>> > >> (assuming > >> > >>>>> 2 dB per step)? > >>>>> > >>>>> > >>>> Possible? Yes. > >>>> > >>>> Likely? I don't know. There are a lot of side effects > >>>> > >> that happen > >> > >>>> when the threshold is raised... > >>>> > >>>> 73, > >>>> > >>>> Lyle KK7P > >>>> > >>>> > >>> ______________________________________________________________ > >>> 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 > > > ---------------------------------------------------------------------- > > -- > > > > > > No virus found in this incoming message. > > Checked by AVG - www.avg.com > > Version: 9.0.733 / Virus Database: 271.1.1/2677 - Release > Date: 02/09/10 02:35:00 > > > > ______________________________________________________________ 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 |
Well, that is a hefty board and circuit change to do what you suggest.
There's currently nothing variable after the SA612. Doesn't reducing the RF (really IF) gain first do fairly much the same thing? Reducing level at Q1 output by reducing at RF gain knob is just barely in front of the SA 612 second mixer and lowers input to ADC at the same time. Seems like a pretty good pragmatic engineering choice. In terms of what an operator can really do with the controls on a stock K3 (as opposed to a theoretical modified K3), would you be recommending leaving PRE set all the time, and only using the RF (IF) gain to keep ambient noise appropriately to the low end of the SA612/ADC ranges? 73, Guy. On Wed, Feb 10, 2010 at 4:20 PM, Joe Subich, W4TV <[hidden email]> wrote: > > Don, > >> Can you elaborate your reasons for this suggestion. > > Adding attenuation before the first active stage (amplifier) > always reduces noise figure because that's where the S/N > ratio is determined provided the first stage has enough > gain to override the noise of the next stage. > >> I had come to believe that the best situation is to place >> attenuation before the first mixer to give the greatest >> amount of dynamic range (headroom). > > That assumes any IMD is produced only in the first mixer. > In the K3, the limiting factor is almost certainly later in > the chain because of the very good IMD performance of the KR > (first) mixer. Without specific analysis, the weakest link > is probably the ADC followed by the second mixer. If it was > the first mixer, narrowing the roofing filter would not > improve the dynamic range. That's why I would do two stages > of gain reduction - 10 dB in the 30 kHz IF followed by 6 dB > in the 8.125 MHz IF, if needed. > > A designer always wants to make sure any amplifier gain is > sufficient for the noise figure of the succeeding stage > but low enough to avoid overload down the line. > > 73, > > ... Joe, W4TV > > > > >> -----Original Message----- >> From: Don Wilhelm [mailto:[hidden email]] >> Sent: Wednesday, February 10, 2010 1:06 AM >> To: Joe Subich, W4TV >> Cc: [hidden email] >> Subject: Re: [Elecraft] K3 DSP AGC Question >> >> >> Joe, >> >> Can you elaborate your reasons for this suggestion. I had come to >> believe that the best situation is to place attenuation >> before the first >> mixer to give the greatest amount of dynamic range (headroom). >> >> Yes, I agree that the AGC Threshold could be raised in the K3 >> and would >> be beneficial. I have felt the default of 005 was too low. >> >> 73, >> Don W3FPR >> >> Joe Subich, W4TV wrote: >> > Perhaps one should get the ambient well down in the ADC operating >> > range but killing gain (adding loss) before the first mixer and >> > the roofing filter is not the way to do it. If you want to >> > better align the dynamic range of the receiver (or specifically >> > the ADC) to conditions, the attenuation should come in the >> > IF - preferably divided between the first IF and 2nd IF. >> > >> > However, there would still be no apparent reason that the K3 >> > should not be capable of sustaining an AGC threshold at least >> > 10 db higher than currently set with AGC THR = 008 whether >> > that be reached with preamp on, preamp off or attenuator on. >> > >> > 73, >> > >> > ... Joe, W4TV >> > >> > >> > >> > >> >> -----Original Message----- >> >> From: [hidden email] >> >> [mailto:[hidden email]] On Behalf Of Guy >> >> Olinger K2AV >> >> Sent: Monday, February 08, 2010 1:49 PM >> >> To: [hidden email] >> >> Cc: [hidden email] >> >> Subject: Re: [Elecraft] K3 DSP AGC Question >> >> >> >> >> >> It may be a dance, but hopefully careful intelligent musing >> >> over the matter is convincing people that they should get the >> >> ambient well down in the analog-to-digital converter (ADC) >> >> operating range. If they do, a -99 threshold is a -109 >> >> threshold, and further backing off RF gain can make it a -119 >> >> or -129 threshold as far as the ADC is concerned, and >> >> headroom is being used for what headroom should be used for. >> >> >> >> One thing for sure, there has not been a good-enough >> >> presentation of what is going on, and people really don't >> >> seem to get it. For something that is plain indisputable >> >> physics, people are still running PRE and max RFgain on 80 >> >> with fast AGC, and are honestly dismayed and confused about >> >> the inevitable outcome, incorrectly blaming the rig for being >> >> natively noisy, no-work NR and NB, filter "ringing", unable >> >> to pull signals out of noise, and more. >> >> >> >> Maybe the variable gain by band in the MP (with a menu >> >> override) was really a better strategy for a default. This >> >> same issue dogged Orion owners, and by the chatter a lot of >> >> them never understood either. >> >> >> >> There IS something entirely separate with the headphone audio >> >> and HI-Z headsets, high volume levels, maybe a sharp >> >> saturation point, and mush, just haven't nailed it yet. >> >> >> >> 73, Guy. >> >> >> >> On Mon, Feb 8, 2010 at 12:01 PM, Joe Subich, W4TV >> >> <[hidden email]> wrote: >> >> >> >>> >> >>>> Likely? I don't know. >> >>>> >> >>> Likely is a better choice since raising the AGC threshold >> >>> >> >> seems to be >> >> >> >>> the primary goal of much of the "PRE/ATT/RF Gain dance" we've seen >> >>> recently. >> >>> >> >>> The hardware AGC (HAGC) would seem to provide an ultimate limit on >> >>> level to the ADC - unless the ADC can't handle the >> >>> >> >> transient peaks - >> >> >> >>> so a higher threshold for the DSP derived AGC would be >> >>> >> >> helpful in many >> >> >> >>> ways. >> >>> >> >>> 73, >> >>> >> >>> ... Joe, W4TV >> >>> >> >>> >> >>> >> >>> >> >>> >> >>>> -----Original Message----- >> >>>> From: [hidden email] >> >>>> [mailto:[hidden email]] On Behalf Of >> Lyle Johnson >> >>>> Sent: Monday, February 08, 2010 11:24 AM >> >>>> To: [hidden email] >> >>>> Subject: Re: [Elecraft] K3 DSP AGC Question >> >>>> >> >>>> >> >>>> Hello Joe! >> >>>> >> >>>>> Assuming that the threshold values have not changed in a >> >>>>> >> >> major way >> >> >> >>>>> since Jack's measurements, would it be possible to >> >>>>> >> >> extend the range >> >> >> >>>>> of threshold values - say to AGC THR=016 at about -80dBm >> >>>>> >> >> (assuming >> >> >> >>>>> 2 dB per step)? >> >>>>> >> >>>>> >> >>>> Possible? Yes. >> >>>> >> >>>> Likely? I don't know. There are a lot of side effects >> >>>> >> >> that happen >> >> >> >>>> when the threshold is raised... >> >>>> >> >>>> 73, >> >>>> >> >>>> Lyle KK7P >> >>>> >> >>>> >> >>> ______________________________________________________________ >> >>> 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 >> > >> ---------------------------------------------------------------------- >> > -- >> > >> > >> > No virus found in this incoming message. >> > Checked by AVG - www.avg.com >> > Version: 9.0.733 / Virus Database: 271.1.1/2677 - Release >> Date: 02/09/10 02:35:00 >> > >> > > > ______________________________________________________________ > 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 |
> In terms of what an operator can really do with the controls > on a stock K3 (as opposed to a theoretical modified K3), > would you be recommending leaving PRE set all the time, and > only using the RF (IF) gain to keep ambient noise > appropriately to the low end of the SA612/ADC ranges? I have not considered keeping PRE on all the time though I seem to need it above 14 MHz due to my poor antennas. I do not know the range of the ADC but find it extremely odd that the (relatively sharp) ACG threshold would be less than 50 dB above the noise floor (-138 dBm MDS). 73, ... Joe, W4TV > -----Original Message----- > From: [hidden email] [mailto:[hidden email]] On Behalf > Of Guy Olinger K2AV > Sent: Wednesday, February 10, 2010 4:54 PM > To: Joe Subich, W4TV > Cc: [hidden email]; [hidden email] > Subject: Re: [Elecraft] K3 DSP AGC Question > > > Well, that is a hefty board and circuit change to do what you > suggest. There's currently nothing variable after the SA612. > Doesn't reducing the RF (really IF) gain first do fairly much > the same thing? Reducing level at Q1 output by reducing at > RF gain knob is just barely in front of the SA 612 second > mixer and lowers input to ADC at the same time. Seems like a > pretty good pragmatic engineering choice. > > In terms of what an operator can really do with the controls > on a stock K3 (as opposed to a theoretical modified K3), > would you be recommending leaving PRE set all the time, and > only using the RF (IF) gain to keep ambient noise > appropriately to the low end of the SA612/ADC ranges? > > 73, Guy. > > On Wed, Feb 10, 2010 at 4:20 PM, Joe Subich, W4TV > <[hidden email]> wrote: > > > > Don, > > > >> Can you elaborate your reasons for this suggestion. > > > > Adding attenuation before the first active stage (amplifier) always > > reduces noise figure because that's where the S/N ratio is > determined > > provided the first stage has enough gain to override the > noise of the > > next stage. > > > >> I had come to believe that the best situation is to place > attenuation > >> before the first mixer to give the greatest amount of > dynamic range > >> (headroom). > > > > That assumes any IMD is produced only in the first mixer. > > In the K3, the limiting factor is almost certainly later in > the chain > > because of the very good IMD performance of the KR > > (first) mixer. Without specific analysis, the weakest link is > > probably the ADC followed by the second mixer. If it was the first > > mixer, narrowing the roofing filter would not improve the dynamic > > range. That's why I would do two stages of gain reduction - > 10 dB in > > the 30 kHz IF followed by 6 dB in the 8.125 MHz IF, if needed. > > > > A designer always wants to make sure any amplifier gain is > sufficient > > for the noise figure of the succeeding stage but low enough > to avoid > > overload down the line. > > > > 73, > > > > ... Joe, W4TV > > > > > > > > > >> -----Original Message----- > >> From: Don Wilhelm [mailto:[hidden email]] > >> Sent: Wednesday, February 10, 2010 1:06 AM > >> To: Joe Subich, W4TV > >> Cc: [hidden email] > >> Subject: Re: [Elecraft] K3 DSP AGC Question > >> > >> > >> Joe, > >> > >> Can you elaborate your reasons for this suggestion. I had come to > >> believe that the best situation is to place attenuation before the > >> first mixer to give the greatest amount of dynamic range > (headroom). > >> > >> Yes, I agree that the AGC Threshold could be raised in the K3 and > >> would be beneficial. I have felt the default of 005 was too low. > >> > >> 73, > >> Don W3FPR > >> > >> Joe Subich, W4TV wrote: > >> > Perhaps one should get the ambient well down in the ADC > operating > >> > range but killing gain (adding loss) before the first > mixer and the > >> > roofing filter is not the way to do it. If you want to better > >> > align the dynamic range of the receiver (or specifically > the ADC) > >> > to conditions, the attenuation should come in the IF - > preferably > >> > divided between the first IF and 2nd IF. > >> > > >> > However, there would still be no apparent reason that > the K3 should > >> > not be capable of sustaining an AGC threshold at least > 10 db higher > >> > than currently set with AGC THR = 008 whether that be > reached with > >> > preamp on, preamp off or attenuator on. > >> > > >> > 73, > >> > > >> > ... Joe, W4TV > >> > > >> > > >> > > >> > > >> >> -----Original Message----- > >> >> From: [hidden email] > >> >> [mailto:[hidden email]] On Behalf Of > Guy Olinger > >> >> K2AV > >> >> Sent: Monday, February 08, 2010 1:49 PM > >> >> To: [hidden email] > >> >> Cc: [hidden email] > >> >> Subject: Re: [Elecraft] K3 DSP AGC Question > >> >> > >> >> > >> >> It may be a dance, but hopefully careful intelligent > musing over > >> >> the matter is convincing people that they should get > the ambient > >> >> well down in the analog-to-digital converter (ADC) operating > >> >> range. If they do, a -99 threshold is a -109 threshold, and > >> >> further backing off RF gain can make it a -119 or -129 > threshold > >> >> as far as the ADC is concerned, and headroom is being used for > >> >> what headroom should be used for. > >> >> > >> >> One thing for sure, there has not been a good-enough > presentation > >> >> of what is going on, and people really don't seem to > get it. For > >> >> something that is plain indisputable physics, people are still > >> >> running PRE and max RFgain on 80 with fast AGC, and are > honestly > >> >> dismayed and confused about the inevitable outcome, incorrectly > >> >> blaming the rig for being natively noisy, no-work NR and NB, > >> >> filter "ringing", unable to pull signals out of noise, and more. > >> >> > >> >> Maybe the variable gain by band in the MP (with a menu > >> >> override) was really a better strategy for a default. This same > >> >> issue dogged Orion owners, and by the chatter a lot of > them never > >> >> understood either. > >> >> > >> >> There IS something entirely separate with the headphone > audio and > >> >> HI-Z headsets, high volume levels, maybe a sharp > saturation point, > >> >> and mush, just haven't nailed it yet. > >> >> > >> >> 73, Guy. > >> >> > >> >> On Mon, Feb 8, 2010 at 12:01 PM, Joe Subich, W4TV > >> >> <[hidden email]> wrote: > >> >> > >> >>> > >> >>>> Likely? I don't know. > >> >>>> > >> >>> Likely is a better choice since raising the AGC threshold > >> >>> > >> >> seems to be > >> >> > >> >>> the primary goal of much of the "PRE/ATT/RF Gain dance" we've > >> >>> seen recently. > >> >>> > >> >>> The hardware AGC (HAGC) would seem to provide an > ultimate limit > >> >>> on level to the ADC - unless the ADC can't handle the > >> >>> > >> >> transient peaks - > >> >> > >> >>> so a higher threshold for the DSP derived AGC would be > >> >>> > >> >> helpful in many > >> >> > >> >>> ways. > >> >>> > >> >>> 73, > >> >>> > >> >>> ... Joe, W4TV > >> >>> > >> >>> > >> >>> > >> >>> > >> >>> > >> >>>> -----Original Message----- > >> >>>> From: [hidden email] > >> >>>> [mailto:[hidden email]] On Behalf Of > >> Lyle Johnson > >> >>>> Sent: Monday, February 08, 2010 11:24 AM > >> >>>> To: [hidden email] > >> >>>> Subject: Re: [Elecraft] K3 DSP AGC Question > >> >>>> > >> >>>> > >> >>>> Hello Joe! > >> >>>> > >> >>>>> Assuming that the threshold values have not changed in a > >> >>>>> > >> >> major way > >> >> > >> >>>>> since Jack's measurements, would it be possible to > >> >>>>> > >> >> extend the range > >> >> > >> >>>>> of threshold values - say to AGC THR=016 at about -80dBm > >> >>>>> > >> >> (assuming > >> >> > >> >>>>> 2 dB per step)? > >> >>>>> > >> >>>>> > >> >>>> Possible? Yes. > >> >>>> > >> >>>> Likely? I don't know. There are a lot of side effects > >> >>>> > >> >> that happen > >> >> > >> >>>> when the threshold is raised... > >> >>>> > >> >>>> 73, > >> >>>> > >> >>>> Lyle KK7P > >> >>>> > >> >>>> > >> >>> ______________________________________________________________ > >> >>> 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 > >> > > >> > --------------------------------------------------------------------- > >> - > >> > -- > >> > > >> > > >> > No virus found in this incoming message. > >> > Checked by AVG - www.avg.com > >> > Version: 9.0.733 / Virus Database: 271.1.1/2677 - Release > >> Date: 02/09/10 02:35:00 > >> > > >> > > > > > ______________________________________________________________ > > 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 |
In reply to this post by Guy, K2AV
AA4AK
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