interference on tv

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Old 08-03-06, 03:46 AM
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interference on tv

why there is an interference of tv the moment I switching on at any switch of the house? is there a problem on the circuit? pls. help this is the case of my neighborhood.
I can't find any wrong with the circuit. lighting has separated 15 amp breaker.
 
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Old 08-03-06, 09:02 AM
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Common causes of interference are dimmer switches and fluorescent light fixtures. If the problem is caused by a dimmer switch, the solution is to replace the dimmer with a switch that has reduced RF emissions. Interference caused by fluorescent fixtures can be reduced by making sure that you have the correct bulb in the fixture to match the ballast; or by replacing the ballast with a low RF emission ballast. Also, you can try to move the TV away from the fluorescent light fixture.

If you do not have dimmers or fluorescent fixtures, perhaps the TV, TV cable or antenna is located too close to power lines. If the coax cable runs next to the power cable inside the wall, that is a likely source of interference.
 
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Old 08-03-06, 09:13 AM
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Anything which makes a spark can cause interference, including light switches. The stronger the tv signal, the less likely you are to see interference. However, if the tv is and older model or you are using an antenna vs cable, you are more prone to interference.
Remember that the first wireless signals were sent by spark gap transmitters.
 
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Old 08-03-06, 09:59 PM
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That type of interference can be picked up on your AM radio.
Flip the switch to get the noise started.
Put radio in the battery mode and start turning off the breakers. When the noise stops, check as see what type of loads are on the circuit. You will need to unplug one at a time. You have something arcing causing the noise. eg doorbell transformer, gold fish bowl pump or heater, electric blanket(I hope you are not using this now), heating pad, breaker arcing in the panel or anything in the house. Also could be a receptacle with loose connection. Please let us know what you found.
 
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Old 08-04-06, 09:11 AM
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I had a call complaining that my ham radio was jamming their TV. As we talked, they said "there it is now". Since I was talking to them and not on the radio, I asked about their furnace - did it just come on? Yes. Is it an oil fired furnace? Yes. Have your ignitor cleaned or repaired and your interference will stop.

Have also tracked down problems due to flashing Christmas lights, and bad pole transformers. They can cause a problem a city block away.
 
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Old 08-04-06, 09:55 AM
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My tv does the same thing, but only when we turn on the ceiling fan.
 
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Old 08-05-06, 03:08 AM
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yes it has a dimmer switch. to isolate I removed it but problem still exist.

one thing I observed is that the power outlet of tv is closed to tv cable outlet. when I disconnected that power outlet and tried to switch on the light switches and thats it. its solve the problem.


thanks to all of you guys for sharing your ideas.

and now my question is what is the minimum distance of power outlet to tv cable outlet?
 
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Old 08-05-06, 06:39 PM
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Originally Posted by hex boy
and now my question is what is the minimum distance of power outlet to tv cable outlet?
Maybe I am wrong but the only requirement is the they not share the same box. I have CATV right next to 120VAC and have no trouble.

You should suspect the cable running from the splitter or CATV entrance point to your TV. I assume you have analog cable.

-Check all F connectors by unscrewing and making sure the center wire is making good contact with the bulkheads (barrels) on wall plates, splitters, amps and ground blocks.

-If that cable is old and is RG59, it won't do as well as an RG-6 or RG-6 quad shield. If it is inside the wall it's hard to tell what condition it's in in there. Is it possible that the cable was run parallel to the power outlet cable, or that they might be cinched or under the same staple? RG-6 is noticeably thicker than RG-59.

-If practical disconnect the CATV wire on both ends, from the TV and from the CATV splitter or amp. Check continuity between the center and shield and between center and a ground and between shield and a ground. If you've got continuity anywhere there, verify you have no splitter or ground block in the circuit first, and if not, you have a bad CATV cable. Replace.

-Check continuity of the center and shield by shorting one end and measuring the resistance on the other end. If it's not on the order of a few ohms, you may have a problem.

-If you or the CATV company can determine that it is simply a matter of weak signal, I would recommend an Electroline amp. Weak signals usually show up in higher frequencies first, with snowy pictures and interference patterns. Here's a useful chart: http://www.qsl.net/atn/library/Broadcast_freqs.htm
 
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Old 08-07-06, 05:32 AM
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You can legally run low voltage wires (ie telephone, television, etc.) right next to electrical wires. However, you should not. Most people recommend a distance of at least one foot, and crossing at right angles only where necessary.

Just to complete the picture, and so nobody calls me on it, you cannot run low voltage cables in the same conduit as electrical wires.
 
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