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: [email protected] >>> To: [email protected]; [email protected] >>> 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: [email protected] >>> 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:[email protected] >>> >>> 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:[email protected] >>> >>> 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:[email protected] > > 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:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
