sm0kiE
join:2002-01-05
San Gabriel, CA
 ·Charter Pipeline
edit:
July 23rd, @03:25PM
| Blocking TV / Computer monitor interference
I live near a power pole... and it constantly emits some sort of field that makes my CRT monitors shaky and my LCD TV discolored.
I did some research and I believe it's an Electromagnetic Field.
I managed to fix my CRT monitors by upping the refresh rate, but I can't do that to my LCD HDTV. Anybody got suggestions?
By the way, if this is the wrong forum please point me in the right direction. Thanks. |
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ArthurS
Watch Those Blinking Lights
Premium
join:2000-10-28
Hamilton, ON
| How close is the power pole? The reason I ask is that it would need to emit a ridiculously powerful EMI field, and you would need to be extremely close to it, for those kinds of problems to occur, IF they can be blamed for your problems.
Shaky CRT monitors are often caused by the wrong refresh rate. Not sure about your LCD HDTV, but can you describe the discoloration more? Also, do you have any unshielded speakers close to your monitors? |
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sm0kiE
join:2002-01-05
San Gabriel, CA
·Charter Pipeline
| Basically the pole isn't the normal small wooden power pole, but the giant 4x higher metal Eiffel tower looking power poles.
When I initially moved in, the monitor images were all shaky, it looked like the surface of water moving. That was at the default 60hz Windows XP setting. Raising the refresh above 100hz eliminated this problem.
The discoloration on my LCD TV is different. There is no shakiness, but a band of discoloration that stretches the complete horizontal screen and about 1/8 the vertical height of the screen that slowly moves upwards then repeats at the bottom. It basically ups the tint of the affected area. For example people's skin tone will turn pinkish/purplish. |
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ArthurS
Watch Those Blinking Lights
Premium
join:2000-10-28
Hamilton, ON
| said by sm0kiE  :Basically the pole isn't the normal small wooden power pole, but the giant 4x higher metal Eiffel tower looking power poles. When I initially moved in, the monitor images were all shaky, it looked like the surface of water moving. That was at the default 60hz Windows XP setting. Raising the refresh above 100hz eliminated this problem. Problem solved, and highly unlikely to be caused by nearby power line magnetic fields.
said by sm0kiE :The discoloration on my LCD TV is different. There is no shakiness, but a band of discoloration that stretches the complete horizontal screen and about 1/8 the vertical height of the screen that slowly moves upwards then repeats at the bottom. It basically ups the tint of the affected area. For example people's skin tone will turn pinkish/purplish. What you described is what is known as a ground loop problem in your video (otherwise known as a hum bar), and not caused by nearby power line interference. Is all your video equipment plugged into a single AC outlet? If you disconnect your cable feed, does the problem go away? |
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russotto
join:2000-10-05
Collegeville, PA | reply to sm0kiE
It's a 60Hz hum bar, but it's quite possible it's caused by the nearby power line rather than by the more usual ground loop. |
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sm0kiE
join:2002-01-05
San Gabriel, CA | Okay, so I disconnected the cable box but left the TV on. The humm bar is still visible even though the screen is just black. What does this mean? |
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sm0kiE
join:2002-01-05
San Gabriel, CA
edit:
July 23rd, @06:16PM
| Well now that I look at it on the black screen, it's not just one bar, it's two, maybe more small ones that all move uniformly upward.
Should I call an electrician for this problem or a video specialist? |
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punker
deleted by moderator
Premium
join:2004-06-21
Palmdale, CA
clubs:
 ·Time Warner VOIP
·RoadRunner Cable
edit:
July 23rd, @06:41PM
| reply to sm0kiE
said by sm0kiE := The discoloration on my LCD TV is different. There is no shakiness, but a band of discoloration that stretches the complete horizontal screen and about 1/8 the vertical height of the screen that slowly moves upwards then repeats at the bottom. It basically ups the tint of the affected area. For example people's skin tone will turn pinkish/purplish. sounds like it need to be calibrated
LCD's are immune to high magnetic fields
#1 reason i did not get an plasma
your best bet if it's noise .
get an noise filter.
»www.google.com/products/catalog?···t=result |
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wings10
I Am Legend
Premium
join:2004-06-09
South Elgin, IL
clubs: 
edit:
July 23rd, @06:41PM
| I never had to worry or have issues with high magnetic fields.  |
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punker
deleted by moderator
Premium
join:2004-06-21
Palmdale, CA
clubs: | well some of my speakers do not have Magnetic Field Shielding |
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ArthurS
Watch Those Blinking Lights
Premium
join:2000-10-28
Hamilton, ON
| reply to sm0kiE
said by sm0kiE :Well now that I look at it on the black screen, it's not just one bar, it's two, maybe more small ones that all move uniformly upward. Should I call an electrician for this problem or a video specialist? Why spend $$$ on an electrician or specialist when you can do a few things yourself to track down the problem?
First tell me what kind of devices do you have plugged into your HDTV? Does one source/device have more hum bars than the other?
How are all your components are plugged into AC power? One receptacle, several receptacles--do they all share the same AC receptacle? Where are they located and how far from your HDTV?
Is it a rat's nest with your wiring? Keep signal cables separate from AC power cords, keeping a good 6-12 inches of separation between the two.
You need to do a process of elimination here to get to the root of the problem: First unplug everything from your HDTV monitor, then check to see if you have any hum bars. One by one, plug in each device to your HDTV, looking for the hum bars to reappear, one device at a time. Report back your findings. |
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sm0kiE
join:2002-01-05
San Gabriel, CA
·Charter Pipeline
| First of all, thank you for helping.
I have narrowed it down to my cable box. My PS3 and Xbox 360 don't have any bars. The bars only appear when the Component cables from the CATV box are connected (even if the CATV box is off). The lines disappear if I actually unplug the CATV box.
As for the power wires, the are all plugged into one of those 5 socket rectagular things (with an on/off switch), which is plugged into the wall. |
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ArthurS
Watch Those Blinking Lights
Premium
join:2000-10-28
Hamilton, ON
| said by sm0kiE :I have narrowed it down to my cable box. My PS3 and Xbox 360 don't have any bars. The bars only appear when the Component cables from the CATV box are connected (even if the CATV box is off). The lines disappear if I actually unplug the CATV box. In that case you need to call your cable TV provider to get this problem resolved. You may need to have a shield isolator put on your cable feed as well--cable TV feeds are notorious for causing ground loop problems with home AV setups. |
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ArthurS
Watch Those Blinking Lights
Premium
join:2000-10-28
Hamilton, ON
edit:
July 23rd, @08:03PM
| reply to russotto
said by russotto :It's a 60Hz hum bar, but it's quite possible it's caused by the nearby power line rather than by the more usual ground loop. If that truly is the case, that would be a house I certainly wouldn't want to live in! Inverse square law tells me this might happen if you live in a tent directly underneath a high voltage transmission line the size of which supplies a city, but highly unlikely in the average home and the clearances required by zoning laws. |
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sm0kiE
join:2002-01-05
San Gabriel, CA
·Charter Pipeline
| reply to ArthurS
said by ArthurS :said by sm0kiE :I have narrowed it down to my cable box. My PS3 and Xbox 360 don't have any bars. The bars only appear when the Component cables from the CATV box are connected (even if the CATV box is off). The lines disappear if I actually unplug the CATV box. In that case you need to call your cable TV provider to get this problem resolved. You may need to have a shield isolator put on your cable feed as well--cable TV feeds are notorious for causing ground loop problems with home AV setups. Thanks... I'll try that. What should I tell the customer service? It's a ground loop problem and I need a shield isolator? |
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ArthurS
Watch Those Blinking Lights
Premium
join:2000-10-28
Hamilton, ON
| Just explain to them the problem, they may replace the box, component cable (could be either or both), or they may put in the isolator (or fix the cable grounding problem itself), or a combination of all of the above. You may have to be persistent about the problem, especially if the call center is in Asia somewhere. You might want to further eliminate the possibilities by substituting the component cable to the cable box with one that you know works, to see if that's the source of the problem. |
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sm0kiE
join:2002-01-05
San Gabriel, CA
·Charter Pipeline
edit:
July 23rd, @10:22PM
| It does appear to be the component cables because if I hook it up using the coax cables there doesn't seem to be any bars.
The only problem is that coax quality isn't as good as component. The cable box has an HDMI output, I wonder if that will get rid of the bands. |
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ArthurS
Watch Those Blinking Lights
Premium
join:2000-10-28
Hamilton, ON | If your HDTV has an HDMI input, the yes, definitely try using the HDMI output of your cable box. If not, then swap out the component cables. |
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sm0kiE
join:2002-01-05
San Gabriel, CA | Thank you ArthurS, problem solved! |
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dvd536
as Mr. Pink as they come
Premium
join:2001-04-27
Phoenix, AZ
| [OT] Want to have some fun?
at night take one of those long fluorescent tube lights and hold by end and touch other contact to the dirt. the light will turn on just with amount of electric in area.
--
When I gez aju zavateh na nalechoo more new yonooz tonigh molinigh - Ken Lee |
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