Re: [Elecraft] K3 new V3.25 NR not so good for CW week signal
I haven't played with the new NR enough yet but so far I haven't heard any weak CW signals that were lost due to turning on the NR. As long as the signal is still there and the S/N is better I don't mind if the overall volume seems to decrease a little when NR is turned on. The new NR sounds better to me than the old version, but I mostly use a pretty wide filter setting for CW so haven't really tried it with a very narrow filter and weak signal. One small modification I would like is that when AGC is off and NR is turned on, instead of flashing N/A on the display, the NR should simply activate the AGC to the last used setting (Fast or Slow). This is a minor irritation to those of us who frequently jump between AGC-Off and AGC-On: you push NR; it flashes N/A; then you have to push AGC and then NR again. NR should just turn on AGC as necessary. (I don't really care whether or not AGC then remains on when NR is subsequently turned off.) 73, Drew AF2Z On Sat, 15 Aug 2009 13:21:19 -0700, Ron AC7AC wrote: Not just Q-multipliers but go back another generation to the regenerative receiver (or, more properly put, regenerative detector). Same thing. As you narrow the selectivity by adjusting the regeneration closer to the critical point, the gain also increases, just as with a Q-multiplier. I've gotten used to turning up the gain as I narrowed the selectivity on my post-regenerative Homebrew receivers so I didn't miss it on the K3. 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] K3 new V3.25 NR not so good for CW week signal
There is another group of people who appreciate a peaking function for CW. That group is those of use who remember using a Q-multiplier. YES! I still have my old QF-1 in the store roomsure do miss the peak function for weak signal CW. In my view, it would be a definite plus to have a true, tunable, peaking function on the K3!! Electraft, please DO move that feature to the front burner! Charlie, N0TT It had both a peak and null position and worked at the IF frequency. The peak function was super for CW. 73 de Brian/K3KO __ 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] K3 new V3.25 NR not so good for CW week signal
Hello, After testing new beta 3.25 I have fond that new NR software has lost the ability to make weak signals to stand out on low bands. This was one of the best features the K3 had in small and bad QTH like mine, 3 BC and a Big Power Station, all of them at 1 to 2KM away, you can not imaging the QRM I have. I have read here many K3 users in this list are very glad with new NR, I suppose are SSB operators and most using it on normal conversation and not very weak signal. The new NR is quite good for chatting just in the line of my old IC-PRO2, there is no much difference changing the adjustments like the old NR but for CW the old firmware with narrow roofing filter, looks to me a bit but better as an old FT-1000 Peak Filter, very good for 160M. Maybe it could be add in a future firmware for CW operators as a digital Peak Filter similar to old NR. So for me or I go down to V3.19 and missing all new improvements or use my old FT-1000 for Low bands, which is not very good after all money I have spent in my full K3. Thanks, 73. Jaime, EA6NB. __ 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] K3 new V3.25 NR not so good for CW week signal
Jaime . . . Many FT-1000D owners (and non-owners who have used them) have urged implementation of an Audio Peak Filter in the K3 for weak-signal CW work. Only those who have used a 1000D can appreciate why this request keeps recurring. It has nothing to do with fondness for a venerable old rig, and everything to do with the performance of the APF. I continue to marvel at the way white noise and miscellaneous garbage are eliminated at the 50 cycle setting of the K3's DSP. But as good as it is, the signal remains what it is -- there is no peaking as there is with the 1000D. Several of us have discussed this with Wayne from the first days of production, and while it may someday be addressed further, for now the issue is moot. 73, Kent K9ZTV K3 #21 Jaime P.Ullivarri wrote (with word insertions by K9ZTV to improve the English): . . . but for CW the old firmware with narrow roofing filters looks to me but a bit better than the old FT-1000 Peak Filter which was very good for 160M. Maybe it could be added in a future firmware revision for CW operators -- a digital Peak Filter with results similar to the previous NR. So for me either I go down to V3.19 and miss all new improvements, or use my old FT-1000 for Low bands. Having to make this choice is not very good after all the money I have spent in creating a fully-loaded K3. Thanks, 73. Jaime, EA6NB. __ 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] K3 new V3.25 NR not so good for CW week signal
Jaime, There is another group of people who appreciate a peaking function for CW. That group is those of use who remember using a Q-multiplier. It had both a peak and null position and worked at the IF frequency. The peak function was super for CW. 73 de Brian/K3KO K9ZTV wrote: Jaime . . . Many FT-1000D owners (and non-owners who have used them) have urged implementation of an Audio Peak Filter in the K3 for weak-signal CW work. Kent K9ZTV K3 #21 No virus found in this outgoing message. Checked by AVG - www.avg.com Version: 8.5.392 / Virus Database: 270.13.58/2304 - Release Date: 08/15/09 06:10:00 __ 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] K3 new V3.25 NR not so good for CW week signal
Add a vote from me for that please ! Terry G4AMT - Original Message - From: Brian Alsop als...@nc.rr.com Cc: elecraft@mailman.qth.net Sent: Saturday, August 15, 2009 7:29 PM Subject: Re: [Elecraft] K3 new V3.25 NR not so good for CW week signal Jaime, There is another group of people who appreciate a peaking function for CW. That group is those of use who remember using a Q-multiplier. It had both a peak and null position and worked at the IF frequency. The peak function was super for CW. 73 de Brian/K3KO K9ZTV wrote: Jaime . . . Many FT-1000D owners (and non-owners who have used them) have urged implementation of an Audio Peak Filter in the K3 for weak-signal CW work. Kent K9ZTV K3 #21 No virus found in this outgoing message. Checked by AVG - www.avg.com Version: 8.5.392 / Virus Database: 270.13.58/2304 - Release Date: 08/15/09 06:10:00 __ 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] K3 new V3.25 NR not so good for CW week signal
Many FT-1000D owners (and non-owners who have used them) have urged implementation of an Audio Peak Filter in the K3 for weak-signal CW work. The APF on the FT-1000D is exceptional and it's a true gain-producing peaking filter at the center frequency. By contrast, the APF in the Icom 7700/7800 is probably better characterized as an audio bandpass (ABP) filter with no peaking gain at the center frequency. I suppose the ideal APF would incorporate all the attributes of a single-channel parametric EQ with variable Q, frequency, and amplitude. Paul, W9AC __ 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] K3 new V3.25 NR not so good for CW week signal
Brian, Thanks for that reminder. I built a Q-Multiplier at the 85 kHz IF in one receiver I built long ago and it really worked great. When you really cranked it up, it would ring, but then a bit of ringing was preferable to no copy. I never measured the minimum width because I did not have the equipment at the time, but it certainly did work. 73, Don W3FPR Brian Alsop wrote: Jaime, There is another group of people who appreciate a peaking function for CW. That group is those of use who remember using a Q-multiplier. It had both a peak and null position and worked at the IF frequency. The peak function was super for CW. 73 de Brian/K3KO __ 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] K3 new V3.25 NR not so good for CW week signal
Kent, very well put and very true. So far this one very simple feature has kept the K3 from being at the top of the line so to speak. (tin hat on, keep your flames to yourself) It all boils down to having the two radios side by side, and operating weak signal 160 meters for instance. Both receivers hear the signal exactly the same, but a touch of the APF on the old 1000D brings the signal out of the surrounding noise just enough to make copy possible. If you cant hear them you cant work them, and this is the case time after time using the K3, I have to resort to turning on the 1000D to make the contact on extreme weak signals on 160. I am sure others will disagree, and a large part of the K3 ownership may never work with signals that weak, or work 160 even. But for those of us who do the APF is a major tool. To continue to try and duplicate such a simple feature in DSP is just work for naught, the reason its APF is it is Audio Peak Filter, a one chip solution in the real world, and with the rxEQ already in the K3 seems to me a former programmer a simple audio implementation. If some dont like, dont use it. I can only imagine how long the want list must be, and how many times its reshuffled, and unless someone has hollered about it recently it drops down the list even further. For a temporary fix I use an external Datong peak filter, not near as good as the 1000D internal, I will limp along for a while longer, but not forever. 1000D may be ancient technology but if it copies signals the K3 cannot, then all the great numbers on paper in the world do not help you out. The K3 blows the 1000D out of the water on selectivity and close in signal handling, but 90 percent of the time there is no QRM near the weak signal. To me its like the beer commercial that states Drinkability.. On 160 weak signal reception, you need Receivability.. Just want the K3 to be all it can be. 73 Merv KH7C ex K9FD Jaime . . . Many FT-1000D owners (and non-owners who have used them) have urged implementation of an Audio Peak Filter in the K3 for weak-signal CW work. Only those who have used a 1000D can appreciate why this request keeps recurring. It has nothing to do with fondness for a venerable old rig, and everything to do with the performance of the APF. I continue to marvel at the way white noise and miscellaneous garbage are eliminated at the 50 cycle setting of the K3's DSP. But as good as it is, the signal remains what it is -- there is no peaking as there is with the 1000D. Several of us have discussed this with Wayne from the first days of production, and while it may someday be addressed further, for now the issue is moot. 73, Kent K9ZTV K3 #21 Jaime P.Ullivarri wrote (with word insertions by K9ZTV to improve the English): . . . but for CW the old firmware with narrow roofing filters looks to me but a bit better than the old FT-1000 Peak Filter which was very good for 160M. Maybe it could be added in a future firmware revision for CW operators -- a digital Peak Filter with results similar to the previous NR. So for me either I go down to V3.19 and miss all new improvements, or use my old FT-1000 for Low bands. Having to make this choice is not very good after all the money I have spent in creating a fully-loaded K3. Thanks, 73. Jaime, EA6NB. __ 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] K3 new V3.25 NR not so good for CW week signal
I've noticed in homebrew receivers as the bandwidth narrowed, shedding noise and QRM I preferred the gain to go up, increaseing the in-passband signal amplitude. I always attributed it to formative years with a Heathkit Q multiplier. It may be an effect similar to AGC with adjustable flatness (May 1996 analog circuit, in DSP of K3). I found I preferred to have strong signals sound louder rather than perfectly flat. Prolly a psycho-acoustic explanation (or maybe just get my head examined?). In firmware one could increase the audio gain by an adjustable amount as the IF bandwidth was decreased, with an operator-settable scaling number. Say 0 = gain independent of bandwidth, to 100 = gain multiplied by K * (2800/DSP bandwidth). Very similar to the AGC rise scaling. That sounds good to me. __ 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] K3 new V3.25 NR not so good for CW week signal
Not just Q-multipliers but go back another generation to the regenerative receiver (or, more properly put, regenerative detector). Same thing. As you narrow the selectivity by adjusting the regeneration closer to the critical point, the gain also increases, just as with a Q-multiplier. I've gotten used to turning up the gain as I narrowed the selectivity on my post-regenerative Homebrew receivers so I didn't miss it on the K3. Ron AC7AC -Original Message- I've noticed in homebrew receivers as the bandwidth narrowed, shedding noise and QRM I preferred the gain to go up, increaseing the in-passband signal amplitude. I always attributed it to formative years with a Heathkit Q multiplier. It may be an effect similar to AGC with adjustable flatness (May 1996 analog circuit, in DSP of K3). I found I preferred to have strong signals sound louder rather than perfectly flat. Prolly a psycho-acoustic explanation (or maybe just get my head examined?). In firmware one could increase the audio gain by an adjustable amount as the IF bandwidth was decreased, with an operator-settable scaling number. Say 0 = gain independent of bandwidth, to 100 = gain multiplied by K * (2800/DSP bandwidth). Very similar to the AGC rise scaling. That sounds good to me. __ 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] K3 new V3.25 NR not so good for CW week signal
At 12:29 PM 15/08/09, you wrote: Jaime, There is another group of people who appreciate a peaking function for CW. That group is those of use who remember using a Q-multiplier. It had both a peak and null position and worked at the IF frequency. The peak function was super for CW. 73 de Brian/K3KO I had one of those, a Heathkit QF-1, my first kit. My RX was an S-85, RX was Heath AT-1. I didn't get to build the AT-1, but I did build some neat 6L6 rigs. I loved that QF-1, $9.99, and that was expensive! Back in the KN8ILI days. Neighbor ham friend was KN8IQY, now K8IQY. He was way ahead of me with a DX-35 or DX-40. Good stuff! John k7up K3, K2's, K1 __ 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] K3 new V3.25 NR not so good for CW week signal
This is sorta already there if you have multiple roofing filters. You can define the gain that is added when each filter kicks in. On Sat, 2009-08-15 at 13:50 -0600, William Carver wrote: I've noticed in homebrew receivers as the bandwidth narrowed, shedding noise and QRM I preferred the gain to go up, increaseing the in-passband signal amplitude. I always attributed it to formative years with a Heathkit Q multiplier. It may be an effect similar to AGC with adjustable flatness (May 1996 analog circuit, in DSP of K3). I found I preferred to have strong signals sound louder rather than perfectly flat. Prolly a psycho-acoustic explanation (or maybe just get my head examined?). In firmware one could increase the audio gain by an adjustable amount as the IF bandwidth was decreased, with an operator-settable scaling number. Say 0 = gain independent of bandwidth, to 100 = gain multiplied by K * (2800/DSP bandwidth). Very similar to the AGC rise scaling. That sounds good to me. __ 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] K3 new V3.25 NR not so good for CW week signal
Not really, if you read the recommendations for the filters you will notice that caution is warranted for setting the gain higher than recommended, for IMD prevention if I remember correct. Kind of like the Inrad roofing filters, in some cases the gain is set to high and causes more IMD than without the filter. Some Inrad roofers for the FT-1000D had too much gain and the radio was worse with them installed than without. W8JI had some measurements on those issues. Merv KH7C This is sorta already there if you have multiple roofing filters. You can define the gain that is added when each filter kicks in. On Sat, 2009-08-15 at 13:50 -0600, William Carver wrote: I've noticed in homebrew receivers as the bandwidth narrowed, shedding noise and QRM I preferred the gain to go up, increaseing the in-passband signal amplitude. I always attributed it to formative years with a Heathkit Q multiplier. It may be an effect similar to AGC with adjustable flatness (May 1996 analog circuit, in DSP of K3). I found I preferred to have strong signals sound louder rather than perfectly flat. Prolly a psycho-acoustic explanation (or maybe just get my head examined?). In firmware one could increase the audio gain by an adjustable amount as the IF bandwidth was decreased, with an operator-settable scaling number. Say 0 = gain independent of bandwidth, to 100 = gain multiplied by K * (2800/DSP bandwidth). Very similar to the AGC rise scaling. That sounds good to me. __ 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] K3 new V3.25 NR not so good for CW week signal
Not saying I'd do it. (and I'm not with the 8 filters I have in my radio) but one can if thats what they wish to do. ~Brett On Sat, 2009-08-15 at 12:42 -1000, Merv Schweigert wrote: Not really, if you read the recommendations for the filters you will notice that caution is warranted for setting the gain higher than recommended, for IMD prevention if I remember correct. Kind of like the Inrad roofing filters, in some cases the gain is set to high and causes more IMD than without the filter. Some Inrad roofers for the FT-1000D had too much gain and the radio was worse with them installed than without. W8JI had some measurements on those issues. Merv KH7C This is sorta already there if you have multiple roofing filters. You can define the gain that is added when each filter kicks in. On Sat, 2009-08-15 at 13:50 -0600, William Carver wrote: I've noticed in homebrew receivers as the bandwidth narrowed, shedding noise and QRM I preferred the gain to go up, increaseing the in-passband signal amplitude. I always attributed it to formative years with a Heathkit Q multiplier. It may be an effect similar to AGC with adjustable flatness (May 1996 analog circuit, in DSP of K3). I found I preferred to have strong signals sound louder rather than perfectly flat. Prolly a psycho-acoustic explanation (or maybe just get my head examined?). In firmware one could increase the audio gain by an adjustable amount as the IF bandwidth was decreased, with an operator-settable scaling number. Say 0 = gain independent of bandwidth, to 100 = gain multiplied by K * (2800/DSP bandwidth). Very similar to the AGC rise scaling. That sounds good to me. __ 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] K3 new V3.25 NR not so good for CW week signal
What is the best way of determining the gain setting? Seem to recall an app for this. David Wilburn NM4M Sent from my Verizon Wireless BlackBerry -Original Message- From: Brett Howard br...@livecomputers.com Date: Sat, 15 Aug 2009 15:51:46 To: Merv Schweigertk...@flex.com Cc: Elecraft@mailman.qth.net Subject: Re: [Elecraft] K3 new V3.25 NR not so good for CW week signal Not saying I'd do it. (and I'm not with the 8 filters I have in my radio) but one can if thats what they wish to do. ~Brett On Sat, 2009-08-15 at 12:42 -1000, Merv Schweigert wrote: Not really, if you read the recommendations for the filters you will notice that caution is warranted for setting the gain higher than recommended, for IMD prevention if I remember correct. Kind of like the Inrad roofing filters, in some cases the gain is set to high and causes more IMD than without the filter. Some Inrad roofers for the FT-1000D had too much gain and the radio was worse with them installed than without. W8JI had some measurements on those issues. Merv KH7C This is sorta already there if you have multiple roofing filters. You can define the gain that is added when each filter kicks in. On Sat, 2009-08-15 at 13:50 -0600, William Carver wrote: I've noticed in homebrew receivers as the bandwidth narrowed, shedding noise and QRM I preferred the gain to go up, increaseing the in-passband signal amplitude. I always attributed it to formative years with a Heathkit Q multiplier. It may be an effect similar to AGC with adjustable flatness (May 1996 analog circuit, in DSP of K3). I found I preferred to have strong signals sound louder rather than perfectly flat. Prolly a psycho-acoustic explanation (or maybe just get my head examined?). In firmware one could increase the audio gain by an adjustable amount as the IF bandwidth was decreased, with an operator-settable scaling number. Say 0 = gain independent of bandwidth, to 100 = gain multiplied by K * (2800/DSP bandwidth). Very similar to the AGC rise scaling. That sounds good to me. __ 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
Re: [Elecraft] K3 new V3.25 NR not so good for CW week signal
http://www.elecraft.com/K3/Roofing_Filters.htm What is the best way of determining the gain setting? Seem to recall an app for this. David Wilburn NM4M Sent from my Verizon Wireless BlackBerry -Original Message- From: Brett Howard br...@livecomputers.com Date: Sat, 15 Aug 2009 15:51:46 To: Merv Schweigertk...@flex.com Cc: Elecraft@mailman.qth.net Subject: Re: [Elecraft] K3 new V3.25 NR not so good for CW week signal Not saying I'd do it. (and I'm not with the 8 filters I have in my radio) but one can if thats what they wish to do. ~Brett On Sat, 2009-08-15 at 12:42 -1000, Merv Schweigert wrote: Not really, if you read the recommendations for the filters you will notice that caution is warranted for setting the gain higher than recommended, for IMD prevention if I remember correct. Kind of like the Inrad roofing filters, in some cases the gain is set to high and causes more IMD than without the filter. Some Inrad roofers for the FT-1000D had too much gain and the radio was worse with them installed than without. W8JI had some measurements on those issues. Merv KH7C This is sorta already there if you have multiple roofing filters. You can define the gain that is added when each filter kicks in. On Sat, 2009-08-15 at 13:50 -0600, William Carver wrote: I've noticed in homebrew receivers as the bandwidth narrowed, shedding noise and QRM I preferred the gain to go up, increaseing the in-passband signal amplitude. I always attributed it to formative years with a Heathkit Q multiplier. It may be an effect similar to AGC with adjustable flatness (May 1996 analog circuit, in DSP of K3). I found I preferred to have strong signals sound louder rather than perfectly flat. Prolly a psycho-acoustic explanation (or maybe just get my head examined?). In firmware one could increase the audio gain by an adjustable amount as the IF bandwidth was decreased, with an operator-settable scaling number. Say 0 = gain independent of bandwidth, to 100 = gain multiplied by K * (2800/DSP bandwidth). Very similar to the AGC rise scaling. That sounds good to me. __ 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
Re: [Elecraft] K3 new V3.25 NR not so good for CW week signal
You can pull this off by looking at the filter setup in the K3Config utility or you can find it in the menu of the K3. ~Brett (KC7OTG) On Sun, 2009-08-16 at 02:12 +, dave.wilb...@verizon.net wrote: What is the best way of determining the gain setting? Seem to recall an app for this. David Wilburn NM4M Sent from my Verizon Wireless BlackBerry -Original Message- From: Brett Howard br...@livecomputers.com Date: Sat, 15 Aug 2009 15:51:46 To: Merv Schweigertk...@flex.com Cc: Elecraft@mailman.qth.net Subject: Re: [Elecraft] K3 new V3.25 NR not so good for CW week signal Not saying I'd do it. (and I'm not with the 8 filters I have in my radio) but one can if thats what they wish to do. ~Brett On Sat, 2009-08-15 at 12:42 -1000, Merv Schweigert wrote: Not really, if you read the recommendations for the filters you will notice that caution is warranted for setting the gain higher than recommended, for IMD prevention if I remember correct. Kind of like the Inrad roofing filters, in some cases the gain is set to high and causes more IMD than without the filter. Some Inrad roofers for the FT-1000D had too much gain and the radio was worse with them installed than without. W8JI had some measurements on those issues. Merv KH7C This is sorta already there if you have multiple roofing filters. You can define the gain that is added when each filter kicks in. On Sat, 2009-08-15 at 13:50 -0600, William Carver wrote: I've noticed in homebrew receivers as the bandwidth narrowed, shedding noise and QRM I preferred the gain to go up, increaseing the in-passband signal amplitude. I always attributed it to formative years with a Heathkit Q multiplier. It may be an effect similar to AGC with adjustable flatness (May 1996 analog circuit, in DSP of K3). I found I preferred to have strong signals sound louder rather than perfectly flat. Prolly a psycho-acoustic explanation (or maybe just get my head examined?). In firmware one could increase the audio gain by an adjustable amount as the IF bandwidth was decreased, with an operator-settable scaling number. Say 0 = gain independent of bandwidth, to 100 = gain multiplied by K * (2800/DSP bandwidth). Very similar to the AGC rise scaling. That sounds good to me. __ 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
Re: [Elecraft] K3 new V3.25 NR not so good for CW week signal
Sorry dont think that link had the info you wanted, lost the note I had from Aptos talking about setting the gain of the filters, may have been in the archives. Merv KH7C What is the best way of determining the gain setting? Seem to recall an app for this. David Wilburn NM4M Sent from my Verizon Wireless BlackBerry -Original Message- From: Brett Howard br...@livecomputers.com Date: Sat, 15 Aug 2009 15:51:46 To: Merv Schweigertk...@flex.com Cc: Elecraft@mailman.qth.net Subject: Re: [Elecraft] K3 new V3.25 NR not so good for CW week signal Not saying I'd do it. (and I'm not with the 8 filters I have in my radio) but one can if thats what they wish to do. ~Brett On Sat, 2009-08-15 at 12:42 -1000, Merv Schweigert wrote: Not really, if you read the recommendations for the filters you will notice that caution is warranted for setting the gain higher than recommended, for IMD prevention if I remember correct. Kind of like the Inrad roofing filters, in some cases the gain is set to high and causes more IMD than without the filter. Some Inrad roofers for the FT-1000D had too much gain and the radio was worse with them installed than without. W8JI had some measurements on those issues. Merv KH7C This is sorta already there if you have multiple roofing filters. You can define the gain that is added when each filter kicks in. On Sat, 2009-08-15 at 13:50 -0600, William Carver wrote: I've noticed in homebrew receivers as the bandwidth narrowed, shedding noise and QRM I preferred the gain to go up, increaseing the in-passband signal amplitude. I always attributed it to formative years with a Heathkit Q multiplier. It may be an effect similar to AGC with adjustable flatness (May 1996 analog circuit, in DSP of K3). I found I preferred to have strong signals sound louder rather than perfectly flat. Prolly a psycho-acoustic explanation (or maybe just get my head examined?). In firmware one could increase the audio gain by an adjustable amount as the IF bandwidth was decreased, with an operator-settable scaling number. Say 0 = gain independent of bandwidth, to 100 = gain multiplied by K * (2800/DSP bandwidth). Very similar to the AGC rise scaling. That sounds good to me. __ 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
Re: [Elecraft] K3 new V3.25 NR not so good for CW week signal
dave.wilb...@verizon.net wrote: What is the best way of determining the gain setting? Seem to recall an app for this. David Wilburn NM4M Sent from my Verizon Wireless BlackBerry Perhaps this is what you were looking for Dave, [Elecraft] On K3 crystal filter gain compensation (FLx GN) wayne burdick Mon, 15 Jun 2009 12:26:43 -0700 Lately there has been some discussion about how much gain to add when compensating for loss in the K3's individual crystal filters. The general guideline is as little as possible. I'd suggest starting with 0 and working up to as high as a few dB only if it seems necessary. Narrow bandwidths themselves create a psychoacoustic gain effect, so you don't really have to make up for the entire loss relative to wide filters. Also, excessive gain can in extreme cases worsen the performance of DSP signal processing, such as noise reduction (NR). Finally, AGC tends to flatten signal amplitudes in general, further reducing the need for per-filter compensation. While I'm on this topic, I'd also like to suggest using a minimum of both RX and TX EQ. The '0' levels were carefully determined empirically, and in most cases the optimal values will be well below the maximum range provided. Unless you have an aural sensitivity issue in some pitch range, or a serious mic deficiency, I'd stay between +/- 6 dB. As with filter gain settings, excessive values can result in adverse interaction with the DSP. And yes, there will be per-mode RX EQ in a future firmware revision. Thanks for all the suggestions on this. 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
Re: [Elecraft] K3 new V3.25 NR not so good for CW week signal
I understand where to set the values. I'm asking how to empirically determine the value to use? David Wilburn NM4M Sent from my Verizon Wireless BlackBerry -Original Message- From: Brett Howard br...@livecomputers.com Date: Sat, 15 Aug 2009 19:19:02 To: dave.wilb...@verizon.net Cc: elecraft-boun...@mailman.qth.net; Merv Schweigertk...@flex.com; Elecraft@mailman.qth.net Subject: Re: [Elecraft] K3 new V3.25 NR not so good for CW week signal You can pull this off by looking at the filter setup in the K3Config utility or you can find it in the menu of the K3. ~Brett (KC7OTG) On Sun, 2009-08-16 at 02:12 +, dave.wilb...@verizon.net wrote: What is the best way of determining the gain setting? Seem to recall an app for this. David Wilburn NM4M Sent from my Verizon Wireless BlackBerry -Original Message- From: Brett Howard br...@livecomputers.com Date: Sat, 15 Aug 2009 15:51:46 To: Merv Schweigertk...@flex.com Cc: Elecraft@mailman.qth.net Subject: Re: [Elecraft] K3 new V3.25 NR not so good for CW week signal Not saying I'd do it. (and I'm not with the 8 filters I have in my radio) but one can if thats what they wish to do. ~Brett On Sat, 2009-08-15 at 12:42 -1000, Merv Schweigert wrote: Not really, if you read the recommendations for the filters you will notice that caution is warranted for setting the gain higher than recommended, for IMD prevention if I remember correct. Kind of like the Inrad roofing filters, in some cases the gain is set to high and causes more IMD than without the filter. Some Inrad roofers for the FT-1000D had too much gain and the radio was worse with them installed than without. W8JI had some measurements on those issues. Merv KH7C This is sorta already there if you have multiple roofing filters. You can define the gain that is added when each filter kicks in. On Sat, 2009-08-15 at 13:50 -0600, William Carver wrote: I've noticed in homebrew receivers as the bandwidth narrowed, shedding noise and QRM I preferred the gain to go up, increaseing the in-passband signal amplitude. I always attributed it to formative years with a Heathkit Q multiplier. It may be an effect similar to AGC with adjustable flatness (May 1996 analog circuit, in DSP of K3). I found I preferred to have strong signals sound louder rather than perfectly flat. Prolly a psycho-acoustic explanation (or maybe just get my head examined?). In firmware one could increase the audio gain by an adjustable amount as the IF bandwidth was decreased, with an operator-settable scaling number. Say 0 = gain independent of bandwidth, to 100 = gain multiplied by K * (2800/DSP bandwidth). Very similar to the AGC rise scaling. That sounds good to me. __ 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
Re: [Elecraft] K3 new V3.25 NR not so good for CW week signal
Tnx David Wilburn NM4M Sent from my Verizon Wireless BlackBerry -Original Message- From: Merv Schweigert k...@flex.com Date: Sat, 15 Aug 2009 16:29:47 To: dave.wilb...@verizon.net Cc: Brett Howardbr...@livecomputers.com; elecraft-boun...@mailman.qth.net; Elecraft@mailman.qth.net Subject: Re: [Elecraft] K3 new V3.25 NR not so good for CW week signal dave.wilb...@verizon.net wrote: What is the best way of determining the gain setting? Seem to recall an app for this. David Wilburn NM4M Sent from my Verizon Wireless BlackBerry Perhaps this is what you were looking for Dave, [Elecraft] On K3 crystal filter gain compensation (FLx GN) wayne burdick Mon, 15 Jun 2009 12:26:43 -0700 Lately there has been some discussion about how much gain to add when compensating for loss in the K3's individual crystal filters. The general guideline is as little as possible. I'd suggest starting with 0 and working up to as high as a few dB only if it seems necessary. Narrow bandwidths themselves create a psychoacoustic gain effect, so you don't really have to make up for the entire loss relative to wide filters. Also, excessive gain can in extreme cases worsen the performance of DSP signal processing, such as noise reduction (NR). Finally, AGC tends to flatten signal amplitudes in general, further reducing the need for per-filter compensation. While I'm on this topic, I'd also like to suggest using a minimum of both RX and TX EQ. The '0' levels were carefully determined empirically, and in most cases the optimal values will be well below the maximum range provided. Unless you have an aural sensitivity issue in some pitch range, or a serious mic deficiency, I'd stay between +/- 6 dB. As with filter gain settings, excessive values can result in adverse interaction with the DSP. And yes, there will be per-mode RX EQ in a future firmware revision. Thanks for all the suggestions on this. 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
Re: [Elecraft] K3 new V3.25 NR not so good for CW week signal
Well you can follow the convention that is mentioned I believe in the manual and use the values outlined there. Or find a steady signal on the air (or connect a signal generator) and use the AFV feature to determine the level and detect the reduction in signal level as you adjust through the filters and then you'll know how many dB delta you have between filters. ~Brett PS: The real answer to this question is to put in as little gain as it takes to make you happy and no more. The less you can use the better. On Sun, 2009-08-16 at 02:45 +, dave.wilb...@verizon.net wrote: I understand where to set the values. I'm asking how to empirically determine the value to use? David Wilburn NM4M Sent from my Verizon Wireless BlackBerry -Original Message- From: Brett Howard br...@livecomputers.com Date: Sat, 15 Aug 2009 19:19:02 To: dave.wilb...@verizon.net Cc: elecraft-boun...@mailman.qth.net; Merv Schweigertk...@flex.com; Elecraft@mailman.qth.net Subject: Re: [Elecraft] K3 new V3.25 NR not so good for CW week signal You can pull this off by looking at the filter setup in the K3Config utility or you can find it in the menu of the K3. ~Brett (KC7OTG) On Sun, 2009-08-16 at 02:12 +, dave.wilb...@verizon.net wrote: What is the best way of determining the gain setting? Seem to recall an app for this. David Wilburn NM4M Sent from my Verizon Wireless BlackBerry -Original Message- From: Brett Howard br...@livecomputers.com Date: Sat, 15 Aug 2009 15:51:46 To: Merv Schweigertk...@flex.com Cc: Elecraft@mailman.qth.net Subject: Re: [Elecraft] K3 new V3.25 NR not so good for CW week signal Not saying I'd do it. (and I'm not with the 8 filters I have in my radio) but one can if thats what they wish to do. ~Brett On Sat, 2009-08-15 at 12:42 -1000, Merv Schweigert wrote: Not really, if you read the recommendations for the filters you will notice that caution is warranted for setting the gain higher than recommended, for IMD prevention if I remember correct. Kind of like the Inrad roofing filters, in some cases the gain is set to high and causes more IMD than without the filter. Some Inrad roofers for the FT-1000D had too much gain and the radio was worse with them installed than without. W8JI had some measurements on those issues. Merv KH7C This is sorta already there if you have multiple roofing filters. You can define the gain that is added when each filter kicks in. On Sat, 2009-08-15 at 13:50 -0600, William Carver wrote: I've noticed in homebrew receivers as the bandwidth narrowed, shedding noise and QRM I preferred the gain to go up, increaseing the in-passband signal amplitude. I always attributed it to formative years with a Heathkit Q multiplier. It may be an effect similar to AGC with adjustable flatness (May 1996 analog circuit, in DSP of K3). I found I preferred to have strong signals sound louder rather than perfectly flat. Prolly a psycho-acoustic explanation (or maybe just get my head examined?). In firmware one could increase the audio gain by an adjustable amount as the IF bandwidth was decreased, with an operator-settable scaling number. Say 0 = gain independent of bandwidth, to 100 = gain multiplied by K * (2800/DSP bandwidth). Very similar to the AGC rise scaling. That sounds good to me. __ 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
Re: [Elecraft] K3 new V3.25 NR not so good for CW week signal
Sounds good. Tnx David Wilburn NM4M Sent from my Verizon Wireless BlackBerry -Original Message- From: Brett Howard br...@livecomputers.com Date: Sat, 15 Aug 2009 20:21:22 To: dave.wilb...@verizon.net Cc: elecraft-boun...@mailman.qth.net; Merv Schweigertk...@flex.com; Elecraft@mailman.qth.net Subject: Re: [Elecraft] K3 new V3.25 NR not so good for CW week signal Well you can follow the convention that is mentioned I believe in the manual and use the values outlined there. Or find a steady signal on the air (or connect a signal generator) and use the AFV feature to determine the level and detect the reduction in signal level as you adjust through the filters and then you'll know how many dB delta you have between filters. ~Brett PS: The real answer to this question is to put in as little gain as it takes to make you happy and no more. The less you can use the better. On Sun, 2009-08-16 at 02:45 +, dave.wilb...@verizon.net wrote: I understand where to set the values. I'm asking how to empirically determine the value to use? David Wilburn NM4M Sent from my Verizon Wireless BlackBerry -Original Message- From: Brett Howard br...@livecomputers.com Date: Sat, 15 Aug 2009 19:19:02 To: dave.wilb...@verizon.net Cc: elecraft-boun...@mailman.qth.net; Merv Schweigertk...@flex.com; Elecraft@mailman.qth.net Subject: Re: [Elecraft] K3 new V3.25 NR not so good for CW week signal You can pull this off by looking at the filter setup in the K3Config utility or you can find it in the menu of the K3. ~Brett (KC7OTG) On Sun, 2009-08-16 at 02:12 +, dave.wilb...@verizon.net wrote: What is the best way of determining the gain setting? Seem to recall an app for this. David Wilburn NM4M Sent from my Verizon Wireless BlackBerry -Original Message- From: Brett Howard br...@livecomputers.com Date: Sat, 15 Aug 2009 15:51:46 To: Merv Schweigertk...@flex.com Cc: Elecraft@mailman.qth.net Subject: Re: [Elecraft] K3 new V3.25 NR not so good for CW week signal Not saying I'd do it. (and I'm not with the 8 filters I have in my radio) but one can if thats what they wish to do. ~Brett On Sat, 2009-08-15 at 12:42 -1000, Merv Schweigert wrote: Not really, if you read the recommendations for the filters you will notice that caution is warranted for setting the gain higher than recommended, for IMD prevention if I remember correct. Kind of like the Inrad roofing filters, in some cases the gain is set to high and causes more IMD than without the filter. Some Inrad roofers for the FT-1000D had too much gain and the radio was worse with them installed than without. W8JI had some measurements on those issues. Merv KH7C This is sorta already there if you have multiple roofing filters. You can define the gain that is added when each filter kicks in. On Sat, 2009-08-15 at 13:50 -0600, William Carver wrote: I've noticed in homebrew receivers as the bandwidth narrowed, shedding noise and QRM I preferred the gain to go up, increaseing the in-passband signal amplitude. I always attributed it to formative years with a Heathkit Q multiplier. It may be an effect similar to AGC with adjustable flatness (May 1996 analog circuit, in DSP of K3). I found I preferred to have strong signals sound louder rather than perfectly flat. Prolly a psycho-acoustic explanation (or maybe just get my head examined?). In firmware one could increase the audio gain by an adjustable amount as the IF bandwidth was decreased, with an operator-settable scaling number. Say 0 = gain independent of bandwidth, to 100 = gain multiplied by K * (2800/DSP bandwidth). Very similar to the AGC rise scaling. That sounds good to me. __ 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
