I've been getting reacquainted with my K3 (S/N 67XX) since adding the 100 watt PA module (KPA3A) last weekend. I also updated the firmware to the latest versions and ran the TX Gain Calibration successfully at all three power levels. The K3/10 had been sitting disconnected from everything since maybe 2019 when I used it to test the XV432 transverter I built.
In operating in the early mornings this past week I observed an odd clicking of a relay as I tuned VFO A. Additional experimentation revealed that VFO B would also produce the sporadic relay clicking while tuning that control. There was no apparent pattern to the clicking, i.e. no regular frequency interval at which clicks occurred. In both instances the relay clicking disappeared after a brief warm-up period. I confirmed this behavior again by leaving the shack heat off and the rig off for a couple hours. The Front Panel temperature and PA Temperature both registered 12C on a cold start (yes, it is New Hampshire on a fall day), and the anomalous relay clicking on tuning either VFO A or VFO B ceased once the Front Panel temperature rose above 17C. This behavior was never observed in many years of operating the K3/10 in contests and general DXing, and the shack was plenty cold through those fall and winter mornings until the heat kicked up. I'll open the top cover and determine which relay is being activated during the cold start-up. Both VFO encoders go directly to the Front Panel MCU with no intervening circuitry save for connectors and printed wiring. At first I thought the relay clicking might be from the internal KAT3 ATU, but this behavior occurs in RX mode with no effort to transmit or activate ATU TUNE. It occurs with the ATU bypassed as well as in-circuit. I'm now wondering if the MCU developed a low temperature sensitivity during its long hiatus from daily use? Has anyone seen this kind of low temperature relay clicking when tuning the receiver right after a cold start? Thanks in advance, and 73, Mike, K8CN ______________________________________________________________ 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