Corcom makes a variety of filters that are designed to replace the AC power input connector on PC power supplies. I have done this on two and had good results.
73, Pete N4ZR Sent from my iPhone > On Nov 29, 2019, at 8:59 AM, YL2VW <yl...@lral.lv> wrote: > > Hi > > I suggest checking if there is good electrical contact between the metal > casing of the PC power supply unit (PSU) and the computer metal case itself > - scratch off the case painting under screws keeping both of them together > to provide better contact. > I had terrible RFI from my freshly assembled shack PC this August. And > while experimenting with extra grounding it to get rid of RFI, for my > surprise I discovered that noise goes away by ~95% when I mess with case > screws. Then I scratched the case painting off below the screws and noise > was almost gone. I assume if it would be in neighbors house, I wouldn't > feel it anymore then. > However, there still were some weak RFI birdies here and there (60 Hz > spacing approx), and as it was meant to be my HAM shack PC, I could not > live with idea that I add extra noise on top of existing neighbor's crap. > So I just replaced the PSU to another one I got for free after asking > friends around, and luckily no more RFI issues from this PC. > > The RFI generating PSU was brand-new "Be Quiet! System Power 9 500W" (I > find the name ironical for a PSU generating RFI). The good one had Chieftec > label. Both of them are kind of "made in China, quality controlled in > Germany". > > 73! > Agris/YL2VW > > >> On Tue, 26 Nov 2019 at 13:49, Rodman, David <rod...@buffalo.edu> wrote: >> >> A few ideas might be helpful here. I was at the station over the weekend >> and found a significant amount of noise coming from one of two computers in >> the station. Significant noise S5 at 1820. One computer runs the cluster >> and 2m connection. That was clean. The other handles most of the remote >> chores and has about 15 USB serial devices attached. Everything was off, >> except a battery operated transceiver attached to the receive antenna feed, >> the modem for the cable and my router. One can definitely see that >> operating the computer, closing windows or plugging in USB devices causes >> the modulation on the signal to change, this isolating the source to the >> computer alone and possible connections to peripherals (they were all >> turned off by the way). I did have few chokes available but attaching them >> to the USB wires out of the computer to their various devices made no >> improvement. I could get more specific but need to leave for my office >> now. Any ideas might be helpful and appreciat >> ed. >> >> >> --- >> David J Rodman MD >> Assistant Clinical Professor >> Department of Ophthalmology >> SUNY/Buffalo >> >> Office 716-857-8654 >> _________________ >> Searchable Archives: http://www.contesting.com/_topband - Topband >> Reflector >> > _________________ > Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _________________ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector