I meant when it makes noise the noise comes from the steel panel under the transformer. Quiet ones are quiet (well, reasonably so). Working out the assembly procedure involved doing a lot of different things to see what ended up with the quietest assembly.
I should have mentioned before that the Belleville washer under the nut must be installed "right side up" as described on page 35 of the assy manual. Getting beyond that will involve removing the transformer to check hardware down in the center hole. You can follow the instructions in the manual to check that or just wait to work with Tech Support. I'm not personally familiar with the "bad transformer" issue others reported Tech Support said occurred. 73, Ron AC7AC From: kevino z [mailto:z_kev...@hotmail.com] Sent: Tuesday, December 20, 2016 9:16 AM To: Ron D'Eau Claire Cc: Charlie T, K3ICH; elecraft@mailman.qth.net Subject: Re: [Elecraft] [KPA500] incredible hum from PA Nope. I have one at work and it is quiet. Something is different with this one. As I stated in my original post, I'm confident that Elecraft will make this right. They are great folks over there. -Kevin (KK4YEL) ----- The problem with the world is that the intelligent people are full of doubts, while the stupid ones are full of confidence. On Dec 20, 2016, at 12:12, Ron D'Eau Claire <r...@cobi.biz> wrote: I believe most of the noise comes from the steel bottom of the kpa500. 73, Ron AC7AC -----Original Message----- From: Elecraft [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Charlie T, K3ICH Sent: Tuesday, December 20, 2016 4:40 AM To: elecraft@mailman.qth.net Subject: Re: [Elecraft] [KPA500] incredible hum from PA "No trees were killed in the sending of this message. However, a large number of electrons were terribly inconvenienced !" Yeah, but you have to realize, electrons LIKE to run around madly. They LIVE for the opportunity to be driven by that strange (to them) electromotive force, regardless of whether it's in one direction (DC) or back and forth (AC), just as horses luv to run. They live basically a very nomadic life, jumping from one nucleus to another. They get sluggish if not driven regularly. This is why old stock vacuum tubes can fail while just sitting on the shelf. Electrons also appreciate the applause as horses do when they perform, but seldom get to enjoy it. So, when you make them run, at least provide a little noise so that know they're well liked. Hmmm, maybe THAT"s why the transformer hums? More to the point of the subject, I wonder if it would have been possible to use a brass bolt or maybe even nylon mounting hardware for the big toroid? Probably not worth the effort is a simple re-tightening can fix it. ( You'll just have to provide some outside method of showing your appreciation to the electrons for their efforts.) 73 Charlie k3ICH ______________________________________________________________ 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 r...@elecraft.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 z_kev...@hotmail.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