The magic is only good for one shot Joe. Same thing happened when I saw the Grand Canyon for the second time.
Steve ----- Original Message ----- From: "Joe Subich, W4TV" <li...@subich.com> To: "Wayne Burdick" <n...@elecraft.com> Cc: "Elecraft Reflector" <elecraft@mailman.qth.net> Sent: Sunday, November 14, 2010 9:02 AM Subject: Re: [Elecraft] K3 APF > >> I'm still in a quandry :) > > I am too <G>. The measured results are rather clear but I > miss the "magic" results I saw with 4.16 ... > > The "feeling" I get with 4.21 is that the Q has been reduced > compared to 4.16 but since the quantitative data shows that's > obviously not the case, I'll just need to continue working > with it to see if I can regain the magic. Maybe it is just > conditions ... noise levels have been a lot lower the last > couple days but there haven't been as many weak signals either. > > 73, > > ... Joe, W4TV > > On 11/13/2010 11:48 PM, Wayne Burdick wrote: >> Joe, >> >> If Lyle is using the same algorithm as before, and your results are as >> indicated below (virtually a tie), I don't understand how you could be >> hearing a "lack of ringing" in the new revision. I simply cannot hear >> any difference myself, and I'm extremely picky. We have nearly 100 >> people testing, and only two or three have perceived a difference, so >> given the statistical evidence, I'd suggest that background noise >> conditions are the variable here, not the firmware. Lyle has also >> completely reviewed the DSP implementation -- no change. >> >> But since the customers are always right, I'm still in a quandry :) >> >> tnx >> Wayne >> >> On Nov 13, 2010, at 6:27 PM, Joe Subich, W4TV wrote: >> >>> >>>>> I'll count this as another vote in favor of adding the Variable Q >>>>> setting... >>> >>> Not on your life. The lack of ringing on the newer version seems to >>> go along with a general decline in effectiveness. If anything I'd >>> prefer to see higher Q. >>> >>> Just for grins I reloaded 4.16 to make the same measurements using the >>> XG-2 as I made on 4.21. Here is the comparison: >>> >>> BW 4.21 4.16 >>> ------------------------- >>> 0 dB 1 2 Hz >>> -1 dB 8 9 Hz >>> -6 dB 31 31 Hz >>> -10 dB 52 49 Hz >>> -20 dB 165 162 Hz >>> -30 dB 345 351 Hz >>> Gain 9.0 9.1 dB >>> >>> Unlike W4ZV, I found only a 3 Hz offset in 4.16 (the peak response >>> was 3 Hz above zero beat - or the indicated spot/shift frequency). >>> Even though the test results were generally the same within the >>> measurement tolerances, I still feel the 4.16 version was more effective >>> in on air listening. >>> >>> These measurements were generated with an XG-2 set for 1 uV with the >>> K3 attenuator engaged for an effective signal level of -118 dBm. >>> >>> 73, >>> >>> ... Joe, W4TV >>> >>> On 11/13/2010 8:07 PM, The Smiths wrote: >>>> >>>> I'll count this as another vote in favor of adding the Variable Q >>>> setting... At least a choice of 3 perhaps Wide, Med and Narrow. Even >>>> if one perceives the APF as "less ringy" and comments on it being a >>>> good thing, that means that they are happy to know that the Q got >>>> widened out a little, and things seem to sound "better". >>>> >>>>> From: w5...@cybermesa.net >>>>> To: li...@subich.com; elecraft@mailman.qth.net >>>>> Date: Sat, 13 Nov 2010 21:19:46 +0000 >>>>> Subject: Re: [Elecraft] K3 APF >>>>> >>>>> Joe wrote: >>>>> >>>>>> I did not make similar measurements with the original alpha >>>>>> test version but this version seems subjectively less tight >>>>>> than the original ... there is certainly less ringing with >>>>>> this one but signals did not seem to "pop" like they did on >>>>>> the earlier version when I tried it last night on 160/80/40. >>>>> >>>>> Joe, I agree with your subjective observation. No, the signals don't >>>>> "pop" >>>>> as much -- but there is less ringing. This is a trade-off, of >>>>> course, and >>>>> the precise balance of peak gain versus ringing is always going to be >>>>> a >>>>> matter of personal preference. >>>>> >>>>> I like this less-ringy version better, I think. Haven't had time to >>>>> play >>>>> with it a lot yet, but I will. I'm sure we will see many other >>>>> opinions. So >>>>> far, I think the current version is very smooth and adequately >>>>> "peaky". >>>>> >>>>> (Opinion subject to revision upon more extensive usage.) >>>>> >>>>> Bill W5WVO >>>>> >>>>> >>>>> -----Original Message----- >>>>> From: Joe Subich, W4TV >>>>> Sent: Saturday, November 13, 2010 20:35 >>>>> To: elecraft@mailman.qth.net >>>>> Subject: Re: [Elecraft] K3 APF >>>>> >>>>> >>>>> I made a similar set of measurements ... using the XG-2 and >>>>> the AFV/dBV capability ... >>>>> >>>>> I measure the peak at 1 Hz wide (e.g. -.1dB +/- 1 Hz) >>>>> the 1 dB points are 8 Hz wide >>>>> the 6 dB points are 31 Hz wide >>>>> the 20 dB points are 165 Hz wide >>>>> the 30 dB points are 345 Hz wide >>>>> gain is right at 9 dB. >>>>> >>>>> The measurements were made on 40 Meters with the XG-2 set to >>>>> 1 uV and the K3 attenuator activated yielding a -108 dBm test >>>>> signal. >>>>> >>>>> I did not make similar measurements with the original alpha >>>>> test version but this version seems subjectively less tight >>>>> than the original ... there is certainly less ringing with >>>>> this one but signals did not seem to "pop" like they did on >>>>> the earlier version when I tried it last night on 160/80/40. >>>>> >>>>> 73, >>>>> >>>>> ... Joe, W4TV >>>>> >>>>> >>>>> On 11/13/2010 1:24 PM, Bill W4ZV wrote: >>>>>> >>>>>> For my own curiosity I did some measurements of the latest APF. >>>>>> They agree >>>>>> with >>>>>> measurements of the first release with the exception that the >>>>>> filter peak >>>>>> is >>>>>> now >>>>>> zero beat instead of +10 Hz: >>>>>> >>>>>> Zero beat = 7040.021 >>>>>> Flat passband = 021-020 (both 0.0 to -0.1 dB) >>>>>> -1 dB passband = 026-018 (-1.2 dB and -0.8 dB) >>>>>> -6 dB passband = 037-009 (-5.8 and -6.0 dB) >>>>>> >>>>>> Flat = 2 Hz BW (at zero beat) >>>>>> -1 dB = 8 Hz BW >>>>>> -6 dB = 28 Hz BW >>>>>> >>>>>> I didn't measure the -6 dB BW carefully on the first pass since I >>>>>> was more >>>>>> interested in the -1 dB BW, but this looks similar and agrees with >>>>>> Lyle's >>>>>> 30 >>>>>> Hz >>>>>> design goal. As mentioned previously, the -1 dB BW is important when >>>>>> trying >>>>>> to >>>>>> detect signals below the noise floor since the human ear can detect >>>>>> this >>>>>> difference in marginal conditions. >>>>>> >>>>>> I also checked the gain (APF vs not) which I didn't do >>>>>> before...+9.1 dB >>>>>> which is >>>>>> very close to Lyle's design goal of +9 dB. >>>>>> >>>>>> Nice job Elecraft! >>>>>> >>>>>> 73, Bill >>>>>> >>>>>> >>>>> ______________________________________________________________ >>>>> Elecraft mailing list >>>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft >>>>> Help: http://mailman.qth.net/mmfaq.htm >>>>> Post: mailto:Elecraft@mailman.qth.net >>>>> >>>>> This list hosted by: http://www.qsl.net >>>>> Please help support this email list: http://www.qsl.net/donate.html >>>>> >>>>> >>>>> ______________________________________________________________ >>>>> 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
