Hi Bill, It is a characteristic of transistors. I have always been taught that they need to be biased down to about half their safe output to avoid thermal runaway. That was a long time ago. Things may have changed.
As they heat up, they increase their amplification, as they amplify, they heat up, and so on. Cold temps works the opposite. In the early days of solid state mobile rigs, and during Minnesota winters, we could turn on our rigs and get nothing but maybe a back-light on the dial. After a few minutes, it would start to have sound coming out of the speaker, as the circuit and components warmed up. It also affects the oscillators. Dick, n0ce ________________________________ From: Elecraft <[email protected]> on behalf of Bill Frantz <[email protected]> Sent: Tuesday, October 4, 2016 12:14 AM To: [email protected] Subject: [Elecraft] Cold K3 During the California QSO Party, the temperatures in our operation tent dropped below freezing. Two of us felt that we were not getting full power out of our K3s when the internal temperatures were low. Given that we were using the K3 to measure power output, low temperatures could be affecting the measurement rather than the power. After sending CQ for 5 or 10 minutes, the K3s warmed up and the output power rose to normal. Too bad calling CQ didn't warm the operators as well. HIHI Since we were getting about 90% power with the internal temperatures at zero C, it is not a major issue, but we are curious. Has anyone else experienced this effect? 73 Bill AE6JV ----------------------------------------------------------------------- Bill Frantz | Concurrency is hard. 12 out | Periwinkle (408)356-8506 | 10 programmers get it wrong. | 16345 Englewood Ave www.pwpconsult.com<http://www.pwpconsult.com> | - Jeff Frantz | Los Gatos, Periwinkle Computer Consulting - pwpconsult.com<http://www.pwpconsult.com/> www.pwpconsult.com Security Communications Quality Assurance Promoting Community Through Secure, Reliable Computing. Periwinkle is a husband and wife team with over ... CA 95032 ______________________________________________________________ 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]
