I run 500 watts FT8 6 through 80 meters with a maximum SWR of 1.2 to 1 into an 80 meter full wave loop and a 6 meter beam. Even on the hottest of days I have never seen 70 degrees on the KPA500 utility. BTW, I use it 95% remote and it works great.
If I ever saw over 70 degrees I would let it cool down and look for a problem. The utility is great for remote operation with a program like team viewer or Google Remote. Richard K6VV Sent from my iPhone > On Dec 2, 2020, at 3:02 PM, Dave Cole <d...@nk7z.net> wrote: > > Thank you Bob, getting some actual numbers helps... I cut off operations at > 70C. In fact, if it starts getting above 65, I will terminate ASAP. Knowing > it could get to 90C makes me feel a lot better! > > 73, and thanks, > Dave (NK7Z) > https://www.nk7z.net > ARRL Volunteer Examiner > ARRL Technical Specialist, RFI > ARRL Asst. Director, NW Division, Technical Resources > >> On 12/2/20 1:25 PM, Bob McGraw K4TAX wrote: >> While I don't often run RTTY, I do run a good bit of PSK-31, WSJT-X FT-8 and >> MSK-144 along with CW and SSB modes. I do watch the PA temp, specially as >> it nears 65 to 70 degrees C. I also run with the Fan on #1 or #2 for >> starters. I know some will say it doesn't make a difference while others >> say it will. As to me, I know that heat is the downfall of solid state >> electronics. Cool is always better. >> For the above, I normally run 400 to 500 watts, depending which power >> indicator I choose. And, a very important point, at any time I never >> exceed 500 watts into a well matched load. I do have a Bird 43P with a 500 >> watt, 2 - 30 MHz, element in-line between the amp output and ATU input. I >> also have a 500 watt element, 25 - 60 MHz, for 6 meters. >> Two facts to which I view one must pay attention: {per the KPA500 manual} >> (a) Duty Cycle a 500 watts = 10 minutes key down / 5 minutes standby >> (b) Heat Sink Temp = 90°C Maximum {194° F} >> I view if one exceeds either of these two items above........they just >> became a very underpaid design and test engineer. >> 73 >> Bob, K4TAX >> Message: 1 >> Date: Wed, 2 Dec 2020 08:36:54 -0800 >> From: Dave Cole<d...@nk7z.net> >> To:elecraft@mailman.qth.net >> Subject: Re: [Elecraft] KPA500/KAT500 and RTTY >> Thanks sir... >> 73, and thanks, >> Dave (NK7Z) >> https://www.nk7z.net >> ARRL Volunteer Examiner >> ARRL Technical Specialist, RFI >> ARRL Asst. Director, NW Division, Technical Resources >>> On 12/2/20 8:24 AM, Gordon LaPoint wrote: >>> Dave, >>> >>> I have done many RTTY contests and regular qso's using the >>> KPA500/KAT500/K3 over the last few years. I run full 500 watts with no >>> problems, the temp gets up to the 60 to 65 range a lot when calling CQ >>> in a contest, or during a 10 minute tx.? If the temp gets to 70 then the >>> fan kicks into high gear and is very noisy, but still within specs. >>> Gordon - N1MGO >>> >>>> On 12/2/2020 9:57 AM, Dave Cole wrote: >>>> Hi, >>>> >>>> Any recommendations as to the max power I might run using a KPA500 and >>>> KAT500, on say, a three to five minute transmission? >>>> >>>> Also, what is the recommended max temp for the PA on this device as >>>> measured by the KPA500? >>>> >>> _ >> ______________________________________________________________ >> 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 >> Message delivered to d...@nk7z.net > ______________________________________________________________ > 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 > Message delivered to vetteresto...@gmail.com ______________________________________________________________ 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 Message delivered to arch...@mail-archive.com
