The torque spec is called out in the manual. Why not use a torque wrench? Can we please not resurrect the KPA500 hum thread already beat to death multiple times years ago? Or does everyone need to chime in yet again?
55 inch-pounds. 73 Eric WD6DBM On Mon, Oct 19, 2020, 9:15 PM Bert <[email protected]> wrote: > Toroidal transformers cause very little acoustic hum, unless the core > is not tightly wound or the copper wire windings are loose! > > If you have to tighten the mounting bolt with a torque wrench > to get the transformer quiet, something is wrong! > > Bert VE3NR > > > > > On 2020-10-19 19:59, Jim Spikes N4KH wrote: > > Looking for details from anyone who resolved issues with excessive > > transformer hum during transmit on a KPA-500. > > > > > > > > I have a hum mitigation application note sent from Elecraft tech support. > > But the procedure recommended is pretty involved - removing front/side > > panels, un-plugging connections, removing the transformer, changing > > positions of the rubber discs, and putting it back together. Possibly > more > > than once, depending on the results. > > > > > > > > There is a risk of breaking something, and I'm not sure its going to > solve > > the problem if I'm successful. This is a new out of the box KPA500 kit. > > > > > > > > If anybody has any lessons learned I would appreciate hearing them. > > > > > > > > Jim, N4KH > > > > ______________________________________________________________ > > 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] > ______________________________________________________________ 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]
