My 50 Amp Astron had a piece of cork material glued between the front of the case and the transformer. It started humming one day when the glue dried out and the cork fell. I glued it back in place and all is well.
I had a 70 Amp do the same thing. Maybe try a little piece of some similar material between the side of the case and transformer. Hank K4HYJ ----- Original Message ----- From: Eric Garner (garn...@gmail.com) Date: 04/24/20 12:57 To: Elecraft Discussion List (elecraft@mailman.qth.net) Subject: Re: [Elecraft] OT: Astron RS-35M Transformer Hum Has anyone tried using something like Dynamat (used to damp vibrations in cars). To keep the case from resonating? On Fri, Apr 24, 2020 at 9:17 AM Fernando Sindeaux via Elecraft < elecraft@mailman.qth.net> wrote: > 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 garn...@gmail.com -- --Eric _________________________________________ Eric Garner ______________________________________________________________ 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 h...@optilink.us ______________________________________________________________ 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
