My Astron hums loudly only when the fax machine runs. Otherwise silent. ?interaction puzzling.
On Fri, Apr 24, 2020, 7:35 AM David Bunte <dpbu...@gmail.com> wrote: > David - > > I have an RS-35M, that sits on a shelf under my operating desk. I leave it > on 24/7, and never gave any thought to acoustic hum from it. I just ducked > my head down below the desktop, and 'thought' I could hear some hum. I > turned off the power supply and verified that there is a little bit that I > could detect. I am blessed with better than average hearing for a > 76-year-old, but that is largely thanks to my hearing aids. > > In the past I have had pretty bad hum from power supply transformers, and > the worst case I ever had was totally cured by tightening the bolts that > held the laminations together. That was pretty easy because it was an open > frame transformer in a home brew KW amp. In a number of transformers I have > paid attention to in the past few years, the screws or bolts that hold the > transformer to the chassis go through the corners of the laminations, and > tightening those may also help. > > I have been "told" that acoustic hum is often made more evident because the > chassis is vibrating... and that putting some dampening material (a sheet > of rubber for example) under the transformer goes a long way toward > reducing the problem. > > Best of luck. > > Dave - K9FN > > > > On Fri, Apr 24, 2020 at 10:14 AM David Herring <david.n5...@gmail.com> > wrote: > > > Does anyone have a way to dampen the physical hum generated by the > > transformer in an RS-35M PS? > > > > This really is just transformer hum I’m hearing, not signal hum…my > station > > is fully bonded and as a result quiet in that regard. Most folks > probably > > never hear this hum, but I have been “blessed” with really good hearing > and > > so this hum irritates the dickens out of me. > > > > If push comes to shove, I will relocated the PS farther away from the > > operating position, I just didn’t want to have to extend power and > bonding > > runs and thus am hoping someone has a different idea. > > > > Thanks & 73, > > David N5DCH > > (Formerly AH6TD) > > > > > > ______________________________________________________________ > > 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 dpbu...@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 k7vora...@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
