Hmm. One of the reasons people get a KPA500 is because they can't get 240 to the shack and the KPA will run on 120V. That makes it non-idiotic to inquire upon the 120V supply.
I heard of a problem something like this, not a KPA500, that turned out to be a defective wall outlet. I would imagine that the KPA500 is unforgiving of a precipitous drop in AC voltage. In the case I cite, all kinds of wierdness in the shack went away when the wall outlet was replaced. The defective wall outlet had internal blades that were badly pitted. It was also very old by any means of estimate. I also heard of a power cord that was not crimped correctly inside the molded plug, discovered upon dissection style autopsy afterwards. Other issues would be aluminum wiring that had not been tightened up, a single bad socket in a power strip, etc. Also have heard of a wall socket connection where one of the screws on the outlet had never been tightened. A KPA500 is a hard pull on a 120V socket. It would not matter to the AC power that you were just hitting 10 watts, because you turn on the idling current as soon as any RF is sensed. Do not assume that the 120V supply is A-OK. Verify everything on that 120V circuit, up to and including the breaker in the breaker box. Breakers go bad too. In any event the very best of luck chasing this aggravating problem. Please let us all know what finally turns out to be the actual problem and what you did to fix it. 73, Guy K2AV On Tue, Feb 16, 2016 at 11:48 AM, Cliff Frescura <c...@cfcorp.com> wrote: > Can you measure the 110V line voltage on key down? Is it stiff enough? > > 73, > > Cliff K3LL/6 > > -----Original Message----- > From: Elecraft [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Mike > Crownover > Sent: Tuesday, February 16, 2016 8:22 AM > To: 'Nr4c' > Cc: elecraft@mailman.qth.net > Subject: Re: [Elecraft] KPA500 problem > > Bill, > > Did that, it's set for 110v. I used the yellow tap, which gives me 75 v, > right in the middle of the spec. I did try the other two, but same > behavior. > > Thnaks, > > Mike AD5A > > -----Original Message----- > From: Nr4c [mailto:n...@widomaker.com] > Sent: Tuesday, February 16, 2016 10:19 AM > To: Mike Crownover <a...@gvtc.com> > Subject: Re: [Elecraft] KPA500 problem > > What input voltage is it configured for? > > Check manual for voltage tap info. > > Sent from my iPhone > ...nr4c. bill > > > > On Feb 15, 2016, at 11:11 PM, Mike Crownover <a...@gvtc.com> wrote: > > > > I just bought a lightly used KPA500. It arrived from the seller, well > > packed and complete with cables, manuals, etc. I turned the amp on, > > interfaced it with my K3, keyed the radio and the KPA500 immediately > > shut-off. No fault light or error code, nothing. It shuts down just as > > if I had pressed the power button, the fan runs, etc... The antenna is > > resonant 1:1, I've lowered input power to 10 watts, swapped coax, > > hooked it up to another K3, used RCA to RCA cable, the Elecraft cable, > > etc.. When down to 10 watts input, I can tap the paddle like a > > straight key lightly and the amp works, but put two dits together and > > it > shuts down. > > > > > > > > Has anyone had an experienced anything like this. I keep thinking this > > has to be something simple. > > > > > > > > Mike AD5A > > > > ______________________________________________________________ > > 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 > > n...@widomaker.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 c...@cfcorp.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 k2av....@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
