On the subject of RF interference. Years ago we came back from living in California to Australia. We had a 110V coffee espresso machine. It worked well and we ran it from a voltage changer plugged into the socket. Early rise time, my wife would go into the kitchen and make a coffee.
I'm in the habit of reading my email and surfing at that time (like now in Australia). For weeks and months my internet would go off and come back a few minutes later. I eventually tied it back to the coffee machine/voltage reducer. We stopped using it and all good. The wireless router runs on 2.4Ghz and is located in my study, maybe 30 feet from the kitchen and there is a double brick wall in the way. As an adjunct to this. I switch off my router at midnight and I get much better sleep. On Sun, Nov 12, 2023 at 6:11 AM Joel C. Ewing <jce.ebe...@cox.net> wrote: > I think shielding of the PC itself is unlikely the problem, unless the > case is not properly closed. All PCs I have ever seen have metal cases, > which if properly seated and grounded act as a RF shield, inbound and > outbound. > > Any electric motor could be producing power transients at power on/off > and possible RF interference from contact arcing (which can increase > with motor age), which might travel over the house wiring, or via air > and get picked up by other cables in the room which are connected to the > PC. Any magnetic effects of a motor should be minor by comparison. > > If it's a large enough motor, start up may produce a temporary dip in > voltage big enough to be a problem for a computer that is not powered > through an Uninterruptible Power Supply (UPS). If you notice any lights > flicker when the shredder powers up, that definitely could be an issue. > If you are not already using a UPS for your PC, you probably should be, > for other reasons as well. The shredder definitely should not be plugged > into the same outlet as your computer, and it would be best if it were > on a different house circuit as well. > > If the problem only started occurring after adding RAM, maybe the PC > power supply is now working harder making it more sensitive to power > dips than before. It's also possible the computer may be getting old > enough that the power supply is getting less effective at filtering out RF. > > If for some reason the shredder motor is broadcasting more RF > interference than in the past, keeping it further away from any cables > connecting devices to the PC may help. There are also some relatively > inexpensive ferrite beads that can be clipped onto cables near the > computer to block RFI from entering via that route. > > Assuming you are in a house, the simplest experiment is to try moving > the shredder to another room far away from the PC where it can be > powered from a different house circuit. If that eliminates the problem > and having the shredder in a different room is acceptable, moving the > shredder away from the PC may be the simplest short-term solution. > Otherwise you can either try using a UPS for the PC and/or adding > ferrite RF filters on PC device cables that don't already include a > filter, especially if there are any cables that are routed close to the > shredder. > > JC Ewing > > > On 11/11/23 06:34, Bob Bridges wrote: > > Hah! A few years ago I had my hardware-geek son build my latest tower > PC. It's pretty good - not water-cooled like the one he made for himself, > but a nice big monitor and I finally gave him permission to load me up on > RAM. But ... > > > > Do normal commercial PCs have Faraday cage around them, or something? I > can't use my old paper shredder any more, because when it fires up within > the same room, the PC suddenly dies and has to be rebooted. A minor EMP, I > take it. > > > > --- > > Bob Bridges, robhbrid...@gmail.com, cell 336 382-7313 > > > > /* The will to win is not nearly as important as the will to prepare to > win. -R.M. Knight */ > > > > -----Original Message----- > > From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> On > Behalf Of Leonard D Woren > > Sent: Saturday, November 11, 2023 02:12 > > > > Long ago I was told why my shop didn't carpet the tape storage area. > Apparently some shop that did had a problem with unreadable tapes. > Eventually they figured out that all the unreadable tapes were on the > bottom row of the tape storage. And the outside cleaning people used a > vacuum cleaner... > > > > --- Bob Bridges wrote on 11/8/2023 6:56 AM: > >> /* The more sophisticated the technology, the more vulnerable it is to > >> primitive attack. People often overlook the obvious. -Dr Who, 1978 */ > > > -- > Joel C. Ewing > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN > -- Wayne V. Bickerdike ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
