Hi John, I have a 100W K3 here and my shack is an un air conditioned 20Ft container in tropical north Queensland, Australia. Needless to say, it does tend to get a trifle 'warm' in the wet (summer) season here, with outside temps in the mid to high 30's (Celcius). Internal temps in the container can be as high as 60 degrees with all the windows / doors cloased up. (The radio is not generally operating when temps are that high) I have only ever twice had my K3 shutdown due to over temp, in both cases the shack temp was well over 40 degrees C.. (And closer to 50!) The first time was the internal 2M module shutting down, the second was the main VCO. The K144XV shutdown was cured by updating the firmware to the then latest version, (1.02 I think it was at the time) which increased the shutdown temperature and the second was apparently cured by recalibrating the main VCO. Neither issue has ever come back to haunt me and my K3 does get subjected to some extremely high temperatures due to my living and being portable in the tropics. Never once has my K3 drifted in frequency to any noticable extent though I do have the TCXO option. (In fact, my K3 #4257 is almost fully optioned, it is only missing the second receiver and its associated filters.) In both shutdown cases, my FP temp was over 60 degrees C as indicated by the radios display. 73 de Jeff Cochrane - VK4BOF Innisfail, QLD, Australia Elecraft K3 #4257 + KPA500 + PR6 + K144XV = Multiband greatness!
----- Original Message ----- From: John To: elecraft@mailman.qth.net Sent: Tuesday, May 31, 2011 8:10 AM Subject: [Elecraft] Thermal Stress in K2, K3 and I guess KX3 All, Has anyone seen any degradation or temporary non-operation in the QRP versions of the K2 or K3 while operating in hot conditions? Symptoms might include: - gradual loss in output power - gradual increase in output power - controls stop working due to some processor lockup - unexpected receiver bandwidth changes - frequency drift (although what doesn't drift a little) - any other change that returns to normal upon return to normal temps This question works the other way too. Has anyone seen the above during very cold operation? As for the KX3, has the thermal analysis highlighted any stress point(s)? Thanks. John, kx4o ______________________________________________________________ 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 ______________________________________________________________ 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
