I thought FT8 was a low power mode. Am I wrong? I am not referring to Fox Hound mode. 73 DOUG EI2CN
Sent from my Samsung Galaxy smartphone. -------- Original message --------From: Michael Blake via Elecraft <[email protected]> Date: 17/07/2018 14:12 (GMT+00:00) To: Nr4c <[email protected]> Cc: Elecraft Reflector <[email protected]>, ANDY DURBIN <[email protected]> Subject: Re: [Elecraft] KPA500 thermal clicks While possibly my imagination, after a few months of use I loosened all of the Z bracket to heatsink screws and side panel to heatsink screws and then retightened all of them plus the top cover to Z bracket screws. That seemed to reduce the clicking. Very 73 - Mike - K9JRI > On Jul 17, 2018, at 9:05 AM, Nr4c <[email protected]> wrote: > > “Clicks” caused by the “Z” bracket are well documented and normal. > Personally, I don’t find this “intolerable” or even slightly annoying. My > wall clock “ticks” every second. > > Sent from my iPhone > ...nr4c. bill > > >> On Jul 17, 2018, at 7:56 AM, ANDY DURBIN <[email protected]> wrote: >> >> The clicking of my KPA500 is almost intolerable and I'd like to know if what >> I'm experiencing is typical. >> >> >> In an FT8 TX/RX cycle with output power 126 W my KPA500 clicks 7-8 times >> during 15 second transmit and 7-8 times during 15 second receive. In these >> TX/RX cycles my logger shows the finals temperature swings between 57 deg C >> and 63 deg C. During this test the KPA500 was seeing an SWR of 1.02:1 >> and calculated PA dissipation was 307 W. >> >> >> I don't think this temperature swing is likely to cause the heat sink to >> expand and contract significantly. The thermal mass of the heat sink is >> quite large and the heating and cooling periods are short. The first >> click happens almost as soon as the KPA500 is keyed. >> >> >> I think it is possible that the clicks are caused by expansion and >> contraction of the finals at their mounting points. Is that likely and, >> if so, why would it be considered normal? >> >> >> 73, >> >> Andy k3wyc >> ______________________________________________________________ >> 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] ______________________________________________________________ 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]
