It would seem prudent to install a recording power line monitor. This would give a clue if further line conditioning would be advantageous. Your power company may be able to assist in this matter.
Bob, K4TAX Sent from my iPhone > On Jun 27, 2018, at 3:00 PM, Chris R. NW6V <chrisr...@gmail.com> wrote: > > I may be wrong, but that may not be what Dick, WM6G, is referring to. > > I've had a KPA500 for quite some time, so I have an idea of what > constitutes "normal." > > In the last few months I've noticed that every morning, between roughly > 9-10 AM, I hear brief 1-5 second pulsations of easily audible hum emanating > from the KPA500. The pulsing events last perhaps 30 seconds to a minute, > and may happen more than once. > > Yes, this ceases if the power cord is out or the power switch on the rear > is OFF. But again, it is brief-lived when it occurs, and it's new. > > To me, guessing, it sounds like something connected to the main AC feed is > coming up out of phase, then finally syncing, after which the hum stops. > > A neighbor's solar array? I have no idea as of this point. > > 73 Chris NW6V > > >> Message: 23 >> Date: Wed, 27 Jun 2018 12:48:19 -0500 >> From: Bob McGraw K4TAX <rmcg...@blomand.net> >> To: elecraft@mailman.qth.net >> Subject: Re: [Elecraft] KPA500 Noise While Off >> Message-ID: <47eb73a6-cc2f-5fd6-4318-17e76867d...@blomand.net> >> Content-Type: text/plain; charset=utf-8; format=flowed >> >> Although the front panel switch is OFF, the control circuit of the power >> supply remains ON as long as the rear power switch is ON or power is >> applied.? It is normal to hear a small amount of hum from the power >> transformer and the left rear of the cabinet to be slightly warm.? See >> page 14 of the KPA500 manual for more detail.> >> >> 73 >> Bob, K4TAX > ______________________________________________________________ > 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 rmcg...@blomand.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 arch...@mail-archive.com
