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New ballast killing radio

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The Bishop

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I had several 48" fluorescent light fixtures that needed a new ballast so I replaced the old with new T8 ballast.

Now when I turn on the lights on in my shop the radio speaker almost dies. The sound is so low you can't understand it. It's not the volume, the sound is distorted and muted.

I can disconnect them all except one and the speakers are still muted. When I disconnect the last one the radio sounds return.

The shop is an insulated metal building 40X24.
 

dr pepper

Well-Known Member
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I'd expect this with Am reception, well maybe not as bad as all that.
A harmonic of the switching frequency of the ballasts is interfering with your radio by the sound of it.
 

Les Jones

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Have you replaced the old type choke and starter switch type balasts with electronic balasts ?

Les.
 

MikeMl

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I had several 48" fluorescent light fixtures that needed a new ballast so I replaced the old with new T8 ballast.

Now when I turn on the lights on in my shop the radio speaker almost dies. The sound is so low you can't understand it. It's not the volume, the sound is distorted and muted.

I can disconnect them all except one and the speakers are still muted. When I disconnect the last one the radio sounds return.

The shop is an insulated metal building 40X24.
Welcome to the new world of cheap-crap Chinese switching power supplies where they make more $$$ if they leave out the filters!!!
 

The Bishop

New Member
The radio is a FM station, and it played excellent until I replaced the ballast. Since it is in a metal building I have a section of insulated coaxial cable going from the metal antenna on the Brookstone radio to an old round type TV antenna which is outside the shop on a 20' pole.
We live in the country and the radio signals are sometimes weak, but with this antenna setup I get great reception until I turn on the new shop lights.
I have four newer fluorescent light fixtures that are factory made that do not interfere with the radio sound. I can usually work with just the newer lights and everything is fine but when I need more light the radio dies and I turn on the CD player.
I'm stumped about the T8 ballast.
Before when the lights were T12 ballast the radio worked fine.
 

MikeMl

Well-Known Member
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I would go to a local thrift shop (Habitat for Humanity) and look for a retired fixture with an old iron ballast in it...

I am a weak-signal ham radio enthusiast living in a rural area, and I am on a crusade to eliminate every switching power supply (and solid-state ballast) from my own property. I am winning locally, but cannot control what my neighbors (200 ft from my antennas) do. I have proved (using direction-finding techniques) that my residual noise is coming from my neighbor's Chinese Crap!
 
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dr pepper

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If the lights take out Fm for you then take note that might apply to those around you too, Fm is in the Vhf frequency band and even low power tends to go a long way.
 

The Bishop

New Member
I found two of the older Florissant with new T8 ballast were the problem in the barn. I swapped the two problem lights with two other lights from the Shed next to the barn. I had 8 lights in the barn and 4 lights in the shed.
I swapped the 2 troublesome fixtures and installed them in the Shed now the barn radio works great again.

Don't know why but everything is fine now.
 

dr pepper

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Sussed.
Might be worth checking your grounding to make sure its Ok.
 

tcmtech

Banned
Most Helpful Member
The odds are it's a very cheaply made ballast thats leaking loads of RF harmonics way up into the FM spectrum as other implied.

Now to make some cheap and easy RF chokes to see if that the problem it pretty simple. Just take the leads coming out of the ballast and wrap each of them around a small iron or steel bolt about 10 - 15 times if you can as close to the ballast body as possible being the odds are the leads are working like transmitter antennas and if so the homemade chokes will help knock a good deal of that radiated RF energy down.

Its just an guess and experiment and may not do anything if the RF is being transmitted from the ballast body itself, which is quite possible, being I have seen a few low end electronic ballasts that had all plastic cases rather than the good all metal RF blocking ones the higher quality ones use.
 
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