I have an Astron RS-35A, and also hums, not too loud, but if the Shack is in silence, I can hear it, low but can be heard. 73 to all, Fernando, PY1BL
Sent from my iPhone > On Apr 24, 2020, at 12:17 PM, Robert Sands <k7vora...@gmail.com> wrote: > > 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 fsinde...@yahoo.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
