RF choke


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Old 06-08-14, 08:47 AM
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RF choke

I know there are people who have a better electronic background than I do, so maybe you can help.

A friend an I are having the same issue in out home shops. We have florescent lighting that is causing very bad interference on out radios. It makes it a bit more than annoying to listen to while working there. The lights are your standard tandem 8' strips with 4 x 4' T8 lamps and universal electronic ballasts.

I have tried contacting two ballast manufactures and have gotten no reply from one, and unhelpful reply from the other. A "Its not our problem." kind of answer.

So I am wondering if there is anything I can do? The interference happens on both radios that are plugged in, and battery powered. In my research I have found some people suggesting adding an RF choke some place so i am wondering if these might help: Amazon.com: 4 RFI EMI Snap Ferrite CB Ham Radio RF Choke Filter Phone TV PC speaker noise Coax: Electronics
 
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Old 06-08-14, 09:01 AM
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My Ridgid jobsite radio has a donut type choke on the hot wire inside the cabinet. Reminds me of a CT. About the size of a quarter. Reason I know, is my guys pulled the cord one too many times and broke a wire somewhere. Had to replace the cord when I discovered the choke.
 
  #3  
Old 06-08-14, 09:12 AM
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By "cabinet" I'm guessing your talking about the plastic outside of the radio, correct?
 
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Old 06-08-14, 09:36 AM
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The bothersome noise is on AM ... FM ... or both ?

If it's just AM there isn't going to be a whole lot you can do. Some of the ballast noise leaks back into the wiring but that is only a small percent. Most of the noise is transmitted out thru the tubes.

A choke helps to reduce the noise leaving the fixture thru the wiring but I'm not sure how much it will help overall.

Larry, your "doughnut" type filter keeps noise that is on the AC line from entering the radio.
 
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Old 06-08-14, 09:40 AM
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FM. AM is not even an option.
 
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Old 06-08-14, 01:12 PM
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You're kidding me.... the lights are bothering the FM. I have never seen a ballast bother FM reception..... and you both are having the same problem.

Same radio.... carrying it from one garage to another ?

Are the fixture frames grounded ?


On edit: apparently I'm in the dark here as others are screaming about the amount of noise that the electronic ballasts generate. Whole houses can be impacted by one ballast. I was at another one of my tech sites and apparently other than changing the ballasts there is nothing that can be done. Some have tried an outside antenna with shielded coax and that's helped. Others have tried filters on the actual ballast power wires with little or no difference.

Apparently extra grounds to the fixtures doesn't help either. I can spec out a filter to try but you'd need to put them on all the fixtures. One guy suggested trying one ballast at a time to see if there was one in particular causing the interference.
 

Last edited by PJmax; 06-08-14 at 01:27 PM. Reason: updated reply
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Old 06-09-14, 03:34 PM
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Same radio.... carrying it from one garage to another ?
No, radios are different and about 175 miles away so they are not even on the same electrical system or radio station.

Are the fixture frames grounded ?
Yes.

I have also read about replacing the ballasts from a commercial ballast to a residential one like you find at the big box stores. Some ballasts are marked "residential only' on them and I have read on some sites that they have more "electronic magic" in them to reduce interference. I am fine with changing the ballasts, I just want to make sure that this will/might fix the issue.

PJ, maybe you can confirm this?
 
 

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