due to some kind of interference, monitor display is "shaking"

they are about 1 foot from each other, however, that's about how close they were at the other location.

the first is a 19 inch crt, at 1600x1200, the second is a 15 inch fp, at 1024x768.

So I am not sure it's the two monitors causing the problems together?

how do you mean "Service entrance".

It's a small apartment, but the other one I was at was smaller and i got rid of the "shaking" there.

I did, however, order a new UPS, so I don't know if that will help.

If I remove the coax surge protector, it seems to sometimes be worse.

well, i have noticed sometimes now, not even having coax connection, still problems with monitor shaking ... other times it goes away after removing coax connection, so I am not even sure that's what the problem is now???

I have two monitors near each other, as my video card supports 2.

If this is the problem, though, shouldn't it go away on one if I turn off the power of the other?

Well, I am not sure how much I can verify as it's an apartment, and I cannot rip up things to check on things:)

As far as moving things, when I did move both monitors and computer to other side of the room, yes the shaking seemed to mostly go away, unless I plugged coax surge protector into coax on wall and had grounder cable connected, even though nothing was connected to surge protector!

however, it seems like sometimes the monitor shakes more than others, any ideas?

First ignore everything about the surge protector. It does not even claim to protect your computer from transients that typically damage electronics AND only complicates your analysis. Eliminate it completely while trying to solve the shaking problem. Nothing inside the surge protector will help you solve this problem nor provide useful information.

Second, having all incoming utilities earthed at a common point at the service entrance ... where utility wires meet building wires ... will further eliminate possible reasons for failure. This too is a question to grasp and answer almost as if life depended on it. Unlike things like the surge protector, the common grounding is not a 'witchcraft' suggestion.

Not only turn off that adjacent monitor. Completely disconnect it. As a potential source of external magnetic fields, the only reliable test is to completely disconnect that second monitor so that it never again need be a variable in the analysis. Notice we want only definitive 'yes' or 'no' answers.

Where in the apartment does shaking significantly increase and decrease? You also know where the main breaker box is located. From that, approximate where wires go from AC electric box to the various apartments. Utility wire enters the building where all apartment wires go for electricity. Where in your apartment would those wires route through the walls? Combine those possibilities with where your monitor does and does not shake. Again, no witchcraft. Your analysis should answer these questions up front.

Without eliminating these most common reasons for shaking, then everything done afterwards is akin to speculation - better called witchcraft. Classic reasons for a shaking monitor are external magnetic fields or an unstable (and failing) power supply inside that monitor. Ignore everything else and first deal only with these concepts - these questions. Be concerned about things that create external magnetic fields. You are concerned that all utilities are properly earthed together at the service entrance - which means suspect how cable was installed. Get that surge protector completely out of the analysis since mention of a surge protector here only adds 'witchcraft' to the analysis. Remove that surge protector completely in all tests.

Monitor will shake now and not shake one half hour later when the neighbor's electric hot water heater powers on and off ... which is why your analysis should include a list of building electric appliances. We still don't even know what heavy appliances are major electric consumers meaning we still don't even have basic facts.

What is creating magnetic fields? Stop worrying about myths such as 'connect this wire and sometimes the shaking is less'. Either the shaking is significantly eliminated or you are grasping at straws. Where does the monitor work without shaking? What happens when monitor is powered in another building, or is powered outside on the lawn connected to a 50 foot extension cord - where external magnetic fields would not exist? Get facts. Determine if external magnetic fields, a failing internal power supply, or even improperly connected utilities to the building create your shaking. Until you have eliminated the classic and major reasons, then everything else posted only creates confusion.

Notice the eng> Well, I am not sure how much I can verify as it's an apartment,

I've seen TV antenna isolators that just used capacitors. but yeah it could be done with a tranformer - a single turn for each winding on a UHF-rated balun core would do it. Bye. Jasen

ok here is the problem now. The cable guy came the other day, and after plugging my power into his generator, we observed that the shaking had gone away, and i no longer had a "hum" on my tv card display, or rising horizontal bar.

So we told this to the electrician, who came today.

he said the following

"unable to fix cable line problem. new grounds run, all connection tightened. I did find a loose neutral in main panel and fixed it"

yet the problem remains! Now I am waiting for the cable people to come back, but I am almost positive it's some electrical thing, or something.

Even when I disconnect from coax on wall, my monitor is still shaking.

what can i do now?

So what did you do at the other place to get rid of the shaking?

Ken

You've got a magnetic field somewhere near the monitor. Move the system.

--
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I had the ground line from the coax surge protector go to a screw on socket.

but how can that be the problem, if when I leave it where it is, but plug it in to cable person's generator, it works OK?

ok, here's a picture of my setup, if this helps.

it's just like the way i had it at old apt, too.

Like i said, why did it work OK when i plugged into generator?

thanks

My first thought would be that the source of the magnetic field - whatever it happens to be - isn't being powered by the generator.

Had a similar problem that I beat my head against for months, before realizing it was the el-cheapo amplified speakers that sat on either side of the monitor. The critical clue that finally sunk in: The monitor would "dance" to the music I was playing.

Moving the left speaker (which turned out to be the one containing the system's amplifier and its power supply) about 8 feet away from the monitor cured the problem. Putting it back would make the problem return.

--
Don Bruder - dakidd@sonic.net - New Email policy in effect as of Feb. 21, 2004.
Short form: I'm trashing EVERY E-mail that doesn't contain a password in the
subject unless it comes from a "whitelisted" (pre-approved by me) address.
See  for full details.

Don Bruder wrote: > Had a similar problem that I beat my head against for months, before

In an office building where I once worked, we had a row of PCs (shared resource, before desktop machines) on which the monitor images would often shimmy at the same time. It took us longer than it should have to realize that the wall they were against was next to an elevator shaft, and every time the elevator car came by, the disturbance in the magnetic field would show up on the monitors.

--
Noah

You are driving off anyone with experience to help you. When such people provide a list of things to try, a person without any electromagnetic field training does not select which tests he feels are valid. He says, "Yes Sir", does all those tests, and reports back what was discovered.

Rather than want to solve the problem, you posted:

You are not going to get an answer to that question because 1) that generator provided virtually zero useful information and

2) because you post again saying you know more than people with 30 and 40 years experience doing this stuff. The answer to your question is do it yesterday.

You want to solve the shaking? Then what happened when you ran the system out on the lawn connected to a 50 foot three wire extension cord. How did the system perform when connected to the same power cord and wall receptacle, both sitting inside the room where shaking happens and out on the lawn? Notice we are not for a minute trying to fix the problem. Obviously running on the lawn is no cure. But again, stop trying to fix the problem. We don't care, yet, to fix the problem. By trying to fix the problem, you have taken a simple one day solution and turned it into a week long project.

By now you should have tested the system elsewhere in the apartment AND identified walls containing power wires. Even better do that same test in each location powered from the original wall receptacle (50 foot 3 wire power cord) and from the wall receptacle nearby the new test location. Ignore what the cable man's generator did. It is not relevant or useful until you have performed tests recommended by those with both experience and training in E-M fields.

Also rather useless is discussion of a new ground. Both ends of a ground wire are electrically different, as posted previously. All grounds are different. Therefore the only useful information about a new ground wire says from where to where, how long, and how it was routed. Is the new ground a safety ground, an earth ground, ground to cable, ground from AC electric box to earth? Just saying new ground tells us virtually nothing - zero. Information as useful as that generator.

Does the cable TV wire now connect less than 10 foot to the same earth ground used by AC electric box? Even connecting the cable to a ground screw on a wall receptacle is not same ground. Notice why we have motherboard ground, earth ground, safety ground, cable ground block, etc. All are different even when interconnected. But again, this is why when you are instructed to move the system around the room and test, then you do it and not second guess using symptoms create by a generator.

BTW, you don't seem to get it. You keep looking for an electric wire solution when others keep saying - magnetic fields. Magnetic fields. Massive difference. Magnetic fields. We know you are not getting it because you even tried what would be a total waste of time - the filter.

URL for the picture does not work. But it really does not help much. That picture would not show anything useful. Again, notice the expression so many posted: magnetic fields. Take a picture of the magnetic fields and things that would create such fields. IOW what is behind that wall. Only then are you demonstrating a grasp of what was posted.

You jumped on a total nonsense idea - the Radio Shack filter. You ignored important suggestions such as Don Bruder:

D> ok, here's a picture of my setup, if this helps.

For one thing, the condescension is not at all necessary. Saying I am not interested in solving the problem after I

1)get the cable people to come see if it's on their end (as far as humming on tv) 2)get an electrician to come fix what the cable guy said the problem was, as far as grounding and neutral and what not, is just not honest. Not to mention, I also bought an isolator, as was suggested on here. I was clearly told on here that it could be a grounding issue, which of course the electrician addressed. So how in the world can you act like I haven't done any of the steps?

As I clearly stated before, I did test it elsewhere in the apartment, and the same problem occurred. Why are you telling me to do that again after I have already done it and seen that the same problem occurs?

I never disagreed that it was a magnetic field or what not, I was going on what I was told here and by the cable guy then the electrician.

Saying I challenged a suggestion when I was told several times to try an isolator is just, again, completely dishonest of you, as well as condescending. You act as though I am going off what I think would make sense as opposed to what I have continually heard on here, been told by the cable guy(About the grounding), and then been told by the electrician. How in the world can you say someone is trying to have their own solution when they have consulted numerous professionals that are far more familiar with the symptoms than he?

-- You jumped on a total nonsense idea - the Radio Shack

---filter. You ignored important suggestions such as Don Bruder:

I HAVE tried moving the system, which I also stated, and it did not solve the problem. Why are you lecturing me like a child when you clearly overlooked the fact that I stated I had already tried this approach?

I appreciate all people's help on here, but if you are going to overlook solutions I have tried and make outrageous claims about me not listening to advice when I have clearly demonstrated I have done so, all the while being condescending toward me, perhaps you personally would be happier not responding to my posts anymore.

thanks

there's the url for picture, sorry everyone

ok, apparently I solved a large portion of the problem.

It was apparently not a magnetic issue at all, because if I ran an extension cord from power cord of monitors to another room, the shaking would go away for the most part, but just not in the current room, for whatever reason.

Eventually I figured I'd try the grounder thing you can buy that converts 3 prong to 2 prong, and, on one of the sockets near the computer, it worked! At least, just as much, for the most part, as being in the other room. Strange thing is, if I plug it into the top plug of the same socket, the shaking returns.

Apparently it was an electrical issue, but I have to deal with what I have in this apartment:) thanks for the help everyone