Strange AM radio static noise

My clock radio is virtually useless at night lately in the 500-800 KHz range due to extreme static noise over the stations' broadcast. However, by accident I discovered that the noise virtually disappears when I turn and leave on the light in the walk-in closet. Any idea what might be causing this and how to fix it?

Reply to
cameo
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Possiblbly a bad CFL lamp somewhere. With the cold weather, CFL's do strange things.

Cheers

Reply to
Martin Riddle

Bad electrical connection / wire nut joint, somewhere upstream from the closet light... loading the connection apparently is enough to stop its intermittent connection and arcing.

This is serious, you could have a potential electrical fire in the making. Maybe call in an electrician? ...Jim Thompson

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| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
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Reply to
Jim Thompson

Thanks for the tip. I was thinking it was due to some bad ground connection maybe.

Reply to
cameo

Any poor connection can make minute arcing. You notice it at night on AM stations since most of them must reduce transmitted power at (local) sundown., so your radio AGC's gain goes up to compensate, making it also more sensitive to electrical "static". ...Jim Thompson

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| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
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Reply to
Jim Thompson

I experienced a similar situation several years ago. It turned out that one of the lighting circuit breakers in my service entrance was causing the noise. Simply opening then closing said breaker solved the problem. There were no active loads on that circuit. Go figure.

Reply to
RosemontCrest

I bet it's a touch light switch ?

Jamie

Reply to
Maynard A. Philbrook Jr.

You said "vitually disappears". Does that mean that it's still somewhat audible when the light is turned off?

Check the following with a portable AM radio for EMI:

  1. CFL lights
  2. LED lights
  3. Light dimmers
  4. Arcing connections
  5. Arcing conventional wall switch
  6. Arcing circuit breaker
  7. Alien invaders

However, if it doesn't completely go away when the power it turned off, I would go hunting for switching type wall warts (power supplies and chargers). The Chinese cheap clone variety produce large amounts of RF noise. Almost anything with a switching power supply inside (which is just about anything electronic these days) should be tested.

Also, to be sure that it's actually coming from your house, turn off the power to the entire house at the breaker panel. If the noise is still there, then it's coming from the neighbors (or the alien invaders).

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Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
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Reply to
Jeff Liebermann

You might try a small portable AM radio to sniff around and locate high noi se places. I have the same problem and traced it to my desktop computer whi ch was turned off. Don't know what's wrong with it, but the noise goes away when I disconnect the power plug. It doesn't have a hard power switch, so I have to pull the power plug out of the computer.

-Bill

Reply to
Bill Bowden

If the noise is worse with it off suspect the switch itself.

Try unscrewing the lamp from the socket and see what happens. Keep us "posted".

Reply to
jurb6006

If it's broadband, moving up in frequency more easily locates source. Shortwave, cb, am detection.

Greg

Reply to
gregz

I have the same problem and traced it to my desktop computer

Many desktop computers stay partially on all the time, so that they can do "wakeup from LAN", ie. turn on when a message comes in to the Ethernet port. Some have a yellow LED on the motherboard that stays lit to indicate standby power is on. The network jack lights may still light up, too.

Jon

Reply to
Jon Elson

The problem is gone now. It appears that one of those in-line switches of a nearby lamp was responsible. It provided marginal connection when it was switched on.

Reply to
cameo

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