I know you already ran the cables, but twisted pair would probably help. wunder K6WRU Walter Underwood CM87wj http://observer.wunderwood.org/ (my blog)
> On May 23, 2020, at 9:37 AM, Nicklas Johnson <[email protected]> wrote: > > The backstory as briefly as I can make it: I wanted to place my home > theater subwoofer in the corner of our living room; doing so required > running two speaker wires and a coaxial cable under the house and plugging > the subwoofer into a different outlet than the AV receiver; this in turn > resulted in ground-loop hum (because of a tiny difference in potential > between the two outlets) which I worked around with a set of 1:1 > low-frequency audio isolation transformers. The subwoofer is of a type > that produces a signal based not only on the LFE channel, but also on the > left and right speaker channels, thus the two speaker wires along with the > coaxial cable. > > Now the subwoofer is picking up common mode noise on 20m, which isn't > terribly surprising, as this happens a good bit with consumer-grade > electronics. I'm hoping to mitigate this with some substantial ferrite > clamps for all three connections and as many turns as I can get through > them. > > My hunch is that the best place in the path to clamp them on will be > immediately before the connection to the speaker itself, on the speaker > side of the isolation transformer, but I wanted to get the opinions of > folks who have solved this problem in the past to see if there's any reason > the ferrites should come before the isolation transformers. > > Thoughts? > > Nick > > -- > *N6OL* > Saying something doesn't make it true. Belief in something doesn't make it > real. And if you have to lie to support a position, that position is not > worth supporting. > ______________________________________________________________ > 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]
