I had a to replace a final transistor earlier this year, and after that I checked most of the compeonents and voltages around Q6-8. That is when I noticed that the Q6 had an unhealthy temperature. R50 looked normal and measured 1.5 ohms. The Q6 got glowing hot and the emitter voltage kept rising.
I got this from Elecraft support: "Normally with the 2SC2166 Q6, there is very close to 1.0VDC on the base in transmit, and the emitter is 0.25 to 0.3VDC when in transmit. Q6 does get pretty warm under normal operation too The 2SC5739 has a little higher gain, so it may be producing a great emitter voltage. I have not yet seen a K2 that has the 2SC5739, so I am not sure if this is the case." After that I put some better cooling on Q6 and the radio operates normal, but I still want the Q6 back to normal temperature. I probably need to test replacing Q6 and see what happens. Regards, Lennart -- View this message in context: http://n2.nabble.com/K2-RF-Q6-2SC5739-too-hot-tp1565547p1567666.html Sent from the Elecraft mailing list archive at Nabble.com. _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
