I am glad to see these numbers and comments, because I have wondered about the temperatures. If running on CW in contests, it shows upper 50s and reaches 60C.
Thanks gang! On Sun, May 3, 2020 at 17:42 Dave Cole <[email protected]> wrote: > Pure paranoia! :) > > I tend to creep into things I consider limits, and not race to them. I > normally run the amp in such a way that it never exceeds 60 or at worst > 65 C. Seeing it hit 70 makes me nervous... > > So... > > Prior to any excursions in to the above 70C area I need to learn more, > which is what your post just helped me do! Thank you!! > > Knowing that others can run the KPA500 90C, eases my fear of amp final > damage. > > I have always ran tube amps in the past, and at one point owned a very > sensitive SS amp, which killed a few sets of finals. > > It turns out there were other issues at play, (design issues I think), > but that experience made me very jumpy about SS amps. I almost went > back to tube amps prior to purchasing the KPA500. After owning KPA500 > for a while now, I would never go back to tubes... So I am being as > careful as possible to insure I understand what I am asking the amp to > do, before I ask it to do something it was not designed for. > > 73, and thanks, > Dave (NK7Z) > https://www.nk7z.net > ARRL Volunteer Examiner > ARRL Technical Specialist > ARRL Asst. Director, NW Division, Technical Resources > > On 5/3/20 1:36 PM, Jack Brindle wrote: > > Dave; > > > > The KPA500 will protect itself above 90C, but it will work quite well at > 70C. Why do you stop at 70C? > > > > 73! > > Jack, W6FB > > > > > >> On May 3, 2020, at 1:26 PM, Dave Cole <[email protected]> wrote: > >> > >> Hello, > >> > >> I just got the new MMSSTV software, and will be running a bit of SSTV. > SSTV is 100% duty cycle. > >> > >> Initial testing here indicates no power level is safe... At 150 watts > the KPA500 reaches 70C pretty fast, in under two minutes, and 70C is my > upper limit for testing... At 500 watts it reaches 70C in about the same > time... > >> > >> Can I assume the amp is not the most efficient thing in the world at > 200 watts? > >> > >> If the KPA500 can't deal with 100% duty cycle, for two minutes, how > does the K3 deal with 100 watts for two minutes, at 100% duty cycle? > >> > >> -- > >> 73, and thanks, > >> Dave (NK7Z) > >> https://www.nk7z.net > >> ARRL Volunteer Examiner > >> ARRL Technical Specialist > >> ARRL Asst. Director, NW Division, Technical Resources > >> ______________________________________________________________ > >> 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] > -- 73 de Ted Edwards, W3TB and GØPWW and thinking about operating CW: "Do today what others won't, so you can do tomorrow what others can't." ______________________________________________________________ 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]
