Hi Al, Nice results.
I'd like to note though that adding of the LPF board wasn't the only correction in the past. (I myself was never bothered by those artifacts btw) A much more significant factor in K3's noisy "reputation" I think, was its initial lack of low frequency response,giving it a high-emphasized and fatiguing sound. The correction of the low-end passband response (made several FW's ago) made a night and day difference in its audio quality. All postings about audio problems before this fix -I think- were mainly caused by K3's initial unbalanced audio response resulting in high-pitch/noise reports. 73' Paul PD0PSB Al Lorona wrote: > > I've received 25 votes so far and the rate of new reports has dropped to > zero. So here are the results. > > There were 8 correct votes (including 2 split votes that I counted as 1/2 > a vote each). That is pretty good... I'm not sure I could have identified > the K3 myself. It is slightly better than the 25% we would have expected > from random guesses. > > Receiver #1 was a Ten Tec Omni VI and received 8 votes as the K3. Some of > the comments I got were: > a. "Very sharp filter." > b. "Least fatiguing." > c. "Seems to have some kind of faint signal in the noise." > d. "Not too bad, although I can hear some high frequency blow-by." > e. "A bit of high freq hiss." > > Receiver #2 was an Elecraft KX1. It received 3 votes. Comments included: > a. "Sounded most like my K3 on 160 meters." > b. "Close to a K3." > c. "Definitely don't like this one." > d. "Pretty awful." > > Receiver #3 was the K3, receiving 8 votes. I will discuss this one and its > comments later. > > Receiver #4 was an Elecraft K2 and it got 4 votes. Comments included: > a. "Easiest and cleanest to listen to." > b. "Least noisy." > c. "Easiest to listen to." > d. "Probably a member of the FT1000MP family." > e. "Pretty awful, presenting a LOT of high frequency blow-by." > f. "Lots of out-of-band noise. (But actually kind of soothing....)" > g. "More "honest" in reproducing what is really happening on the band." > > There were 2 votes for "I don't know." > > None of this is really surprising for a subjective (and difficult) test > like this. What was surprising, and which I did not expect, was that of > the 8 votes for the K3 and in comments from the others, *not a single > person identified it because of noise, artifacts, or distortion*, but in > every case by what I would call "normal" factors. Just read these sample > pro and con comments about Receiver #3, the K3, (including a few from the > first run of the test on 6 January that are pertinent): > > a. "I had my K3 set up as you described while listening to your 4 > recordings. Mine sounded identical to number 3. The other waveforms were > different in average pitch." > b. "Well balanced leaned toward allowing lows." > c. "No out of band noise. Very very faint signals audible." > d. "Sounds the most like my K3 sounds with 500 Hz BW." > e. "Most different sound to my K3." > f. "Cleanest overall passband (the others obviously have substantial > wideband gain *after* the CW filter, resulting in surrounding WB noise) - > but K3 has most "bumpy-road" agc." > g. "[The K3] is the most 'quiet' recording because it contains only low > frequency (in-passband) content." > h. "Real quiet outside of the passband noise." > > Without exception, the identifying features cited were purely normal > things like frequency response, passband shape, AGC, etc. In fact, many > folks identified the K3 precisely because of its cleanliness. "No noise," > "Clean," etc. > > (Incidentally, in the first test on 6 Jan 8 out of 15 were correct votes > for the K3 (which was file #1). And the same total absence of > identification by distortion products was true for that test also.) > > I would have expected at least a few folks to say, "Receiver X is the K3 > because I can clearly hear the high frequency products." But they did not. > > Note also that at least four and possibly five of the correct votes were > made with their own K3 turned on, in a side-by-side comparison with my > recordings, which I'm sure definitely helped. :^) Could they have made the > same identification without that to fall back on? I don't know. > > What are we to conclude from all of this? It is the normal > characteristics, rather than the imperfections, that one hears when one > listens to a K3. Second, the K3 is apparently no more noisier a receiver; > at least noisiness is not what jumps out at you when you listen to it in > side-by-side comparisons with other receivers. > > I now suspect that for many (if not all) operators, the effect of 10 and > 12 kHz artifacts etc. is vastly exaggerated. > > I will speculate further and say that a lot of times because we can > measure something, we conclude that what we measured is significant, or > that it must be the cause of what's wrong. If there were no such thing as > spectrum analyzers perhaps most people would be supremely happy with the > way their K3 sounds. But, because we can see something on a plot, we make > a connection between it and some other experience. It's like taking a > blood test and finding out you have high cholesterol and then declaring, > "So that's why I have been having trouble sleeping!" There may, in fact, > be no connection. > > That Elecraft now has a fix for this is incredible. Most manufacturers > would have told us to get lost if we had raised the question (if they had > responded at all). When you think about it, it really is amazing what has > happened here in a matter of just a few weeks. > > There will be the folks that install the new LPF and declare that there is > a night-and-day improvement, that it makes an unusable receiver usable > again. When that happens, someone else can make two recordings, one with > the LPF and one without, to see if we all can come to the same conclusion. > > My sincere thanks for participating and for your patience with me. > > Regards, > > Al W6LX > ______________________________________________________________ > 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 > > -- View this message in context: http://n2.nabble.com/Test-Results-tp4283037p4284746.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:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
