Just sounds like the audio muting during key-down. The K4 speaker probably rolls off below 300Hz while your recording has higher fidelity. External audio devices would have to roll off the low frequency to avoid it. I bet if the K4 used a VCA rather than a simple clamp you probably would not hear this on the line-out during keying. No idea if it is simple hardware or a DSP operation (easily fixed). Either way, the K4 is impressive.
72 de Paul/N6MGN On 6/23/2020 7:23 AM, Victor Rosenthal 4X6GP wrote: > I certainly hope the clicking I hear on the sidetone is an artifact of > the recording process, or something that will go away with the > production version of the K4! > > > 73, > Victor, 4X6GP > Rehovot, Israel > Formerly K2VCO > CWops no. 5 > http://www.qsl.net/k2vco/ > . > On 23/06/2020 12:41, Bob Wilson, N6TV wrote: >> Summary: The K4D Receiver Audio and QSK performance seems >> outstanding -- >> I'm sold. >> >> I hesitated to order a K4 until I could hear how one sounded in "real >> world" pileup conditions, compared to my trusty 11-year old K3s (S/N >> 1494 >> and 1495 with KSYN3A upgrades). >> >> Well, here is a short recording I made while operating a K4D Field Test >> unit during the All Asian CW Contest this past weekend, so you can >> have a >> listen to the QSK performance and the audio tones when several >> stations are >> calling on about the same frequency all at once, which is the typical >> "pileup mush" situation that has been so difficult for most modern >> radios >> to handle (including the K3): >> >> https://www.kkn.net/~n6tv/Pileup_Audio_on_K4D_Field_Test_N6TV.mp3 >> >> (Headphones recommended). >> >> With 2 or 3 guys calling, it seemed *so* much easier to pick out >> callsigns >> with the K4D, compared to my K3, especially when they were very close in >> frequency, which was often. The audio distortion and "beat note >> buzzing" I >> still occasionally hear on the K3 is not heard on the K4. *This alone is >> reason enough for me to order a second K4D* for SO2R contesting. >> >> Note: The "thumps" and clicks you hear in the recording while I'm >> transmitting with full QSK are mostly a side effect of the analog >> recording >> method used (rear headphone jack, long cable, ungrounded radio, and >> microHAM MK2R+ sound card). I think some RF is still getting into the >> MK2R+ despite lots of ferrites. The "thumps" are not heard in the front >> panel headphone jack of the K4. The stereo USB Sound in the K4D >> won't have >> these issues. >> >> I also toggled PRE1 and NR (level 4) when a weak one would call, and it >> really seemed to help pull them out of the noise. I put both >> receivers on >> the same frequency and used A/B to toggle both settings ON and OFF at >> the >> same time with a single tap (Main RX had PRE OFF and NR OFF, Sub RX had >> PRE1 ON and NR ON, and I would swap them). I modified my Win-Test >> scripts >> <https://bit.ly/wtscripts> so I could swap A/B from the keyboard of my >> logging program. I've also made scope control work from the Win-Test >> keyboard, as with my P3 scripts. The radio responds to CAT commands >> instantly, as does the touch screen display. >> >> Unlike the K3, I could keep the RF Gain at MAX and hear no real problem >> until the bands got really noisy, then backing it off helped a bit, >> as did >> the attenuator. But I like the way the fast AGC worked. Loud stations >> never hammered my ears, and there's a new "AGC attack time" setting >> that we >> don't have in the K3 that will require further experimentation. >> >> As for QSK, I went back and forth between QSK ON and QSK OFF, Delay >> 0.00. >> There's a huge difference. QSK OFF Delay 0.00 is much quieter, but I >> like >> to hear more between elements. >> >> QSK performance was *way* better than the K3, especially at high >> speed (I >> went up to 39 WPM). Amp. is a KPA1500. No CW jitter was observed, >> so "CW >> QRQ" mode is no longer needed to send clean CW at high speed with either >> internal or external keying. I used 5 ms of keying compensation and got >> good reports from that, but I need to get out my scope and make some >> measurements. >> >> I figured I would eventually want to order the K4 "HD" model, but I >> may not >> need it. So far the receiver performance seems really good, even when >> getting close to loud signals. But I don't have a way to make the >> careful >> receiver performance measurements that Rob Sherwood, NC0B, can make. >> >> The band scope has much finer resolution than the P3 or an IC-7851, >> but I >> still need to experiment with an external HDMI monitor, which will >> provide >> even more pixels for the band scope. >> >> Physically, a K4D is smaller than the K3/P3 combo. side by side, and >> it's >> only about 3/4" taller and maybe an inch deeper. >> >> The K4 buttons have a very nice tactile feel, much improved over the K3. >> Every knob except AF Gain seems to be an optical encoder rather than >> a pot, >> which means there is potential to control just about everything from >> your >> logging program keyboard, without having to touch the radio. >> >> The "tap to tune" feature of the waterfall display seems to work well >> for >> making big frequency movements. I need to try it with a USB mouse. >> Better >> than that, there's a new method to automatically adjust the band noise >> level on the scope so you don't have to constantly fiddle with a "REF >> LVL" >> setting as we do on the P3. >> >> There's more to write, but this post is long enough already. >> >> In sum, I know we've all been waiting a long time for the K4 to be >> delivered. I think it will be well worth the wait, and that your >> patience >> will be rewarded. Meanwhile, me and my fellow volunteer Field >> Testers will >> be very busy trying to find all the bugs so that you won't have to. :-) >> But as delivered to us, it seems very stable, and very usable. Most >> of the >> major features are working quite well at this point. >> >> 73, >> Bob, N6TV >> ______________________________________________________________ >> 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 >> Message delivered to [email protected] >> > ______________________________________________________________ > 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 > Message delivered to [email protected] ______________________________________________________________ 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 Message delivered to [email protected]
