After several reports that my CW tone sounded less than perfect I've been on a hunt for possible causes. Looking at the TX waveform on my P3 it does look more sausage-shaped than I see in the P3 manual.
So far I've determined my power supply was a little low and sagging a little under full power. After changing cabling and adjusting the PS, I now have 14.2V displayed on the K3 at rest, 13.9 to 14.0V at the 25W level used to drive the KPA500, and 13.7 to 13.8V at 100W output. All that now seems as it should be, but the waveform on the P3 is still elongated. My KPA500 on a 240V outlet shows HV of 73.5V at rest, 57.3V with 500W output. This is a little on the low side, and I may move the HV tap to bring it back up above 60V under load. On air testing today with a neighbor I got the report that my CW sounds just fine until the amp is in line. Then it is described as "some kind of artifact... like a bell sound... like a delay." This is consistent with the other report I had been getting of a "ringing, bell-like" note to my CW. This is most apparent at 30 wpm, as I would be running in a contest. So far, all the reports I have received from fellow amateurs have been after a CW Ops weekly contest, during which I usually am running at 30 wpm and 500W output. During rag chews with a bug at 22-25 wpm and 500W nobody has said anything bad about the CW note. The rig, KAT500 tuner and amp are interconnected via two E850463 Aux Interface Cables as shown on page 5 of the KAT500 Manual, Rev. C6 (3/8/2017). CW for contesting is generated by N1MM+ via the K3S USB interface. I have a K1EL Winkeyer on order in case the root cause is the computer... but that elongated waveform remains the most likely factor to resolve. My guess is the root cause of all this, power supply issues resolved for now, is the elongated waveform I see on the P3. My rise time seems to be at least 3 or 4 times longer than what I see in the ARRL product reviews or even in the P3 manual showing an example of a CW waveform. I have submitted a contact form at the Elecraft support web page, but its the weekend and with them all working from home I wouldn't mind the collective wisdom of the group as to any other avenues of investigation. And, many thanks for the help so far! 73 de Chuck, WS1L -- =================== Chuck Chandler chandler...@gmail.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 Message delivered to arch...@mail-archive.com
