[Elecraft] Test Results

[Al Lorona]

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