My K3s has this problem, but it only happens intermittently. When driving the KPA1500, there would be a spike of about 70w. Drive level was between 20 and 25 watts. The K3s spent three months at Elecraft and they could not fix it. I finally discovered two things that caused the power spike: 1. Exiting the CW QRQ mode; either by turning on RIT or by using the menu. 2. Narrowing the passband from XFIL 3 to XFIL 4 (1000 Hz to 400 Hz in my case.), either with the XFIL button or the Width control. These appear to be the only things that cause the power spike.
This leads me to believe it's a firmware problem (v 5.67, the most recent). I tried going back to an earlier FW version, but could not figure out how to load it. It doesn't look like there will be any new FW updates for the K3 series. --- 73, Mike Cizek WØVTT -----Original Message----- From: elecraft-boun...@mailman.qth.net <elecraft-boun...@mailman.qth.net> On Behalf Of N2TK via Elecraft Sent: Saturday, 20 May, 2023 15:51 To: m...@sj2w.se; elecraft@mailman.qth.net Subject: Re: [Elecraft] Power spike early K3 I had the same problem with the K3/KPA1500 combination. I recalibrated the K3. Then I made sure I don't run the K3 at exactly 5W or 50W. The problem has not reappeared.N2TK, Tony -----Original Message----- From: Mikael Larsmark <m...@sj2w.se> To: elecraft@mailman.qth.net Sent: Sat, May 20, 2023 3:45 am Subject: [Elecraft] Power spike early K3 Hi, We have an early serial K3 which has got an issue with power spikes. I have done a TX gain calibration without it making a difference. The spike happens mainly when you have changed to a new band and during the first transmission. After that the spike is a lot smaller and not much of an issue. Anybody have any ideas of what this could be because of? It kind of makes it impossible to run a solid state amplifier on the radio and probably not good for the tube amplifiers either. /Mike, SJ2W ______________________________________________________________ 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 tony....@verizon.net ______________________________________________________________ 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 mgci...@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
