New UK website on Radio/TV Interference - AVS Forum
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post #1 of 5 Old 04-15-2013, 07:45 AM - Thread Starter
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Although this site is primarily aimed at Ham radio operators, shortwave listeners, and AM radio users, they have some very interesting information on typical noise sources that also plague TV viewers.

You'll want to look at the sections on "SMPS" (Switch-Mode Power Supplies), where they talk about cheap, "knock-off" units from e-bay, that will ruin reception for you and your neighbors.
Also, there are demonstrations of how Plasma TV sets create noise and interference (I know of many that even "self-jam" their own ability to receive signal, especially in the VHF bands).
New, "energy efficient" light bulbs can also create noise, although some are much better than others.

http://www.ukqrm.org.uk/

Ken English, Sr. Engineer, KSL-TV.
"The postings on this site are my own and don't necessarily represent the Company positions, strategies or opinions."
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post #2 of 5 Old 04-15-2013, 10:57 AM
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Good site Ken; thanks!

If you can not measure it, you can not improve it.
Lord Kelvin, 1883
www.megalithia.com/elect/aerialsite/dttpoorman.html
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post #3 of 5 Old 04-16-2013, 12:10 PM
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Good site.
I purchase three CREE LRP38 LED spotlights a couple of years ago to use in an eight foot track light 120V ( no transformer) system.
Each time I turn on the lights (one or all) I would lose channels 7 & 9 which are VHF digital signals. Turn the light(s) off channels 7 & 9 reappear. Have three separate digital tuners that are fed from the same VHF antenna. Same issue with each tuner. The store I purchase the light from sent out replacements. Same problem. I contacted Cree but was never able to get a response from the contact I was given. The lights are nice but they interfere with VHF signals.
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post #4 of 5 Old 04-17-2013, 06:45 AM - Thread Starter
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I notice that they do not show any FCC Part 15 certifications on the bottom of their Spec Sheet:

http://www.cree.com/~/media/Files/Cree/Lighting/Lamps/LRP%2038/Cree_Lamp_LRP_38_SpecSheet.pdf

I don't think I've ever seen one on any LED manufacturers' site.

Ken English, Sr. Engineer, KSL-TV.
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post #5 of 5 Old 04-19-2013, 10:05 PM
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Recently I purchased a single CREE warm white LED 60W replacement bulb recently introduced through Home Depot. The packaging says that it complies with Part 15 of the FCC rules. It does not currently interfere with my digital broadcast TV reception but does create significant interference for AM broadcast band, slight interference for FM broadcast band, and very slight but detectable interference for commercial aircraft and military aircraft communication radio listening. My CCFLs also interfere about the same for AM broadcast band only, but the CREE emissions extend upwards much higher in frequency up to at least 400 MHz.

http://www.flickr.com/photos/by_wally/8594172652/in/photostream
http://www.flickr.com/photos/by_wally/8593031687/in/photostream/
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