TV interference with T8 lights

I decided after the T 12 lights in my attached garage started having problems to replace them with T8's.(Electroonic ballasts) Since doing this, Channel 5 WTVF goes out every time I turn the garage lights on. It goes back to normal when the lights are off.

I have a rooftop antenna a yagi, on a tower right outside my garage. I also have on this tower my dish network dish.

I origionally thought it was probably the light and replaced it with another one from Lowes, but this light did the same thing as well.

Is there a way to diagnose what is causing this or preventing it?

I also have UHF little antennas at varios tv's in the house to be able to work the remote from another bedroom. (Satelite box). however, for a test, I unscrewed one of the antennas at the kitchen tv and it made no difference.

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Easy....get rid of the electronic ballasts, they are transmitters because of the internal square wave choppers. Steve

Reply to
Steve Lusardi

This should not happen.

One assumes that the electronic ballasts are jamming TV reception, but UHF is way above the inverter frequency, which is probably around 20 KHz, with harmonics in the low megahertz.

I would try a different brand of ballast.

You should be able to return the light fixtures as defective, perhaps illegal, because the FCC frowns on such interference.

Joe Gwinn

Reply to
Joseph Gwinn

The remotes work at 2.4Ghz, well within the microwave spectrum. A leaky microwave oven will affect those, not much else.

If the ballasts are putting out that much RFI, you should be wiping out AM reception for quite a ways, a cheap transistor radio should pick that right up. If they're chink fixtures, not much you can do except replace them with something better-made. Another problem, maybe easier to fix, would be that the ballasts aren't radiating but putting out a signal down your AC power lines and that's getting into your electronics that way. RF chokes and filters can be added to kill that off, shouldn't have to be done on correctly designed ballasts, but would be a possible fix. I had a chink-designed motor control that tripped the computer's UPS anytime I used it, had to stick an EMI filter on the power cord to kill that.


Reply to

Thing is, I took one light back to lowes and exchanged it and now this light does it too. It is the commercial stip lights I bought. I really dont want to buy another ballast. And chennel 5 here is broadcast on VHF.

Is there a filter I could install on the coax of the antenna?

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stryped fired this volley in news:b6f8cb95-2d0b-

It's _actually_ on the old VHF channel 5? That's not unheard-of, but pretty rare. Most digital channels (even if the _show_ as (say) "channel

5.1" are up in the 7-14 range, or up...

You ARE in a pickle. The way the old FCC regs read, if the device is "approved" and it causes interference, it's as much the receiver's duty to deal with it (re-orient the receiving antenna, etc.) as the transmitter's.


Reply to
Lloyd E. Sponenburgh

I assume that the replacement is the same make and model.

US Channel 5 is 76 MHz through 82 MHz, which is way higher than any reasonable inverter harmonics. For instance, the 20th harmonic of a 20 KHz inverter square wave is 0.4 MHz. So there is a problem in the ballast design, and I have no idea how this got by the FCC.

I would try a better make and model fixture.

Certainly, but it should not be necessary, and the filter may be more expensive than getting a fixture that does not have the problem. Shielding an ~80 MHz signal at the likely power level isn't all that cheap.

I have eight 4-tube T8 fixtures in my shop, and have no such problem.

By the way, how does over-the-air FM radio fare? The FM band is between TV channels 6 and 7, so if TV 5 is in trouble, the FM band may also be.

And, how is AM band reception?

Joe Gwinn

Reply to
Joseph Gwinn

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