Post by thread:EMI in my room [OT] HELP

Hi to all engineers, Sorry for OT question since this is a smart list I decided to ask this question.After I moved and started to setup my PC monitors in my room I noticed that monitors are shaky. First I tried to change settings it didn't effect at all when I started to move the monitor around I noticed there are a few spots that shakes less but still is not expectable. I tried to cover with the coil it helps but very little. I disconnected almost every thing but still doing it and last thing I tried is I used backupUPS and turned the main power off the monitor still was shaky. I tried 3 different monitors they all shaky but more or less. next to my house about 20 feet a way there is a power electrical post. I am not sure if it comes from there. any help will highly appreciated . Andre

Maybe the monitor is fine, and you are shaking. Tipping the bottle lately? I have seen monitors get angry like that, and it is almost always a 60 Hz field from just outside of the monitor. If I take the linear supply I have an set it on top of the monitor (voice of experience here) then it does just that. Of course, I do this sober. Chris Eddy Andre Abelian wrote: > Sorry for OT question since this is a smart list > I decided to ask this question.After I moved > and started to setup my PC monitors in my room > I noticed that monitors are shaky. First I tried to change

Andre Abelian <spam_OUTPICLISTTakeThisOuTMITVMA.MIT.EDU> wrote: > After I moved and started to setup my PC monitors in my room I > noticed that monitors are shaky. First I tried to change settings > it didn't effect at all when I started to move the monitor around I > noticed there are a few spots that shakes less but still is not > expectable. I tried to cover with the coil it helps but very > little. I disconnected almost every thing but still doing it and > last thing I tried is I used backupUPS and turned the main power > off the monitor still was shaky. Andre: It's probably your UPS that's causing the interference. Turn it off and plug everything directly into the wall; if that solves the problem, you'll need to get longer power cords so you can move the UPS as far away from your monitor as possible. -Andy === Andrew Warren - .....fastfwdKILLspam@spam@ix.netcom.com === Fast Forward Engineering - San Diego, California === http://www.geocities.com/SiliconValley/2499

I disagree. It is highly unlikely that the UPS is causing the problem. Most use SMPS so there is no LF magnetic field to radiate and beat with the monitor scan rate. He didn't say that the shake got worse when he engaged the UPS (where there is more likelyhood of radiated field from the high power xformer). He also said he could find places where is shook less. While low power line voltage could cause the monitor to shake, it wouldn't change with orientation. I would assume that he also didn't have the problem in his previous location, and I would expect the UPS to have been in close proximity at the old location. Andre said "next to my house about 20 feet a way there is a power electrical post." It is more likely that he is suffering from radiated LF magnetic field from a power transformer on the pole. If moving a 12" square sheet of steel (unroll a big 'tin' can to use as a shield) around the monitor changes the shake, he has external magnetic interference. Call the power company (after confirming that you have a power transformer on the pole) and complain about the 'radiation' you are being exposed to. They are PARANOID about potential lawsuits from EMF exposure so they will come out and change the transformer proto. If they won't, go to the media with the story about being 'exposed to unwanted EMF'. There is lots of literature, pro and con as to the deleterious effects of exposure to EMF, so you have a very big club to use on the power company (even if it's wrong <G>). Where PR is concerned perception is everything. Andrew Warren wrote: {Quote hidden}> Andre Abelian <PICLISTKILLspamMITVMA.MIT.EDU> wrote: > > > After I moved and started to setup my PC monitors in my room I > > noticed that monitors are shaky. First I tried to change settings > > it didn't effect at all when I started to move the monitor around I > > noticed there are a few spots that shakes less but still is not > > expectable. I tried to cover with the coil it helps but very > > little. I disconnected almost every thing but still doing it and > > last thing I tried is I used backupUPS and turned the main power > > off the monitor still was shaky. > > Andre: > > It's probably your UPS that's causing the interference. Turn it off > and plug everything directly into the wall; if that solves the > problem, you'll need to get longer power cords so you can move the > UPS as far away from your monitor as possible. > > -Andy > > === Andrew Warren - .....fastfwdKILLspam.....ix.netcom.com > === Fast Forward Engineering - San Diego, California > === http://www.geocities.com/SiliconValley/2499 -- Robert.Rolf-AT-UAlberta.ca U of Alberta, Neuroscience, 513 HMRC Edmonton, Alberta, Canada, T6G 2S2

Robert Rolf <EraseMEPICLISTspam_OUTTakeThisOuTMITVMA.MIT.EDU> wrote: > I disagree. It is highly unlikely that the UPS is causing the > problem. Well, we won't know for sure until Andre does some testing... But three weeks ago, when I moved MY office, my monitor was doing the same thing and it demonstrably WAS caused by the UPS. > He didn't say that the shake got worse when he engaged the UPS Right... Probably because he never DISengaged the UPS to see if it got better. > He also said he could find places where is shook less. While low > power line voltage could cause the monitor to shake, it wouldn't > change with orientation. I would assume that he also didn't have > the problem in his previous location, and I would expect the UPS > to have been in close proximity at the old location. Well, yes and no. He JUST moved, so his computer, monitor, and UPS might all be living next to each other on the floor while he waits for his furniture to arrive. That was the situation at my place for a day, and as soon as I got my furniture and set everything up as it had been at the old place, the problem went away. -Andy === Andrew Warren - fastfwdspam_OUTix.netcom.com === Fast Forward Engineering - San Diego, California === http://www.geocities.com/SiliconValley/2499

Try getting a magnet and mapping the source of the fields. You may have a defective wire in your wall, or a radio tower on the top of the hill. Andre Abelian wrote: {Quote hidden}> Hi to all engineers, > > Sorry for OT question since this is a smart list > I decided to ask this question.After I moved > and started to setup my PC monitors in my room > I noticed that monitors are shaky. First I tried to change > settings it didn't effect at all when I started to move the monitor > around I noticed there are a few spots that shakes less > but still is not expectable. I tried to cover with the coil it > helps but very little. I disconnected almost every thing but > still doing it and last thing I tried is I used backupUPS and > turned the main power off the monitor still was shaky. I tried > 3 different monitors they all shaky but more or less. > next to my house about 20 feet a way there is a power electrical post. > I am not sure if it comes from there. > any help will highly appreciated . > > Andre -- Daniel Hart Embedded System Design Engineer NBS Technologies, Inc. (Card Technology Corp.) 70 Eisenhower Drive, Paramus, NJ 07652, USA +1 201 845 7373 x183 @spam@dhartKILLspamnbstech.com