Radio Frequency Interference with T-5 Lights

[bookman51]

I just got installed t-5 lights is my metal pole building. Unfortunately turning on the lights knocks (creates a loud buzz) on most of the radio stations I want to listen to (both AM and FM).

I had asked the supplier ahead of time if there would be a problem and he said "no." The supplier called the company (Atlas Lights) they said they seldom have of a problem. Well, I doubt it given what I see on the internet and in talking with friends with metal pole buildings.

It is definitely the lights. Turn them on...just a buzz for all but stations in town. I can pick up okay both local AM and FM stations but anything over 30 miles away has a loud buzz. Turn the lights off, and I can pick up what I always picked up

Are there solutions? I have tried relocating the radios (I have two in my shop), checking out the sound with a newer radio, moving the antenna, grounding one of the radios (had a screw on it that said ground), etc. Still the same problem.

I reviewed some of the threads on the forum but did not see a solution, but hopefully someone has one.

Thanks in advance.

 

[pattenp]

This is not much help but there is a thread on here about the problem and I believe someone posted a line filter that helps. Keep searching.

Edit: Post #18

http://www.garagejournal.com/forum/showthread.php?t=138207&highlight=filter


*

 

[bookman51]

This is not much help but there is a thread on here about the problem and I believe someone posted a line filter that helps. Keep searching.

Edit: Post #18

http://www.garagejournal.com/forum/showthread.php?t=138207&highlight=filter


*

Thanks, If I read correctly, the line filter is about $25 each. I have nine lights and they are 15 feet in the air. I rented a sissor lift for the electrian to put them in. Don't what to do it twice! Hope there is an easier solution.

 

[nehog]

You may be able to get away with an external antenna, and a filter at the receiver. I would certainly try that first were this my problem to solve.

 

[bookman51]

You may be able to get away with an external antenna, and a filter at the receiver. I would certainly try that first were this my problem to solve.

So what are we talking about when you say filter? What I have is a older SONY boombox and an older GE radio. I checked with a newer radio and same problem. The older SONY has a telescoping antenna. It might screw off to attach an antenna. Maybe there is an adaptor for a coaxial cable. The older GE radio has an internal antenna and a small screw for an external antenna and another one for a ground. I assume for an external antenna you mean something that uses a coaxial cable and runs to a a remote antenna some distance away from the lights?? I am just trying to be careful about throwing good money after bad. That is, invest in an external antenna and filter and discover I still cannot get most stations with the lights on.

Thanks

 

[RPH]

Depends if the noise is on the line or emitted to the air. Most likely it's on the line. Do the lights have plugs or are they connected directly? If plugs, try a computer filter strip to see if the noise goes away. Unless you have a o-scope around then you can check the line for noise.

 

[bookman51]

Depends if the noise is on the line or emitted to the air. Most likely it's on the line. Do the lights have plugs or are they connected directly? If plugs, try a computer filter strip to see if the noise goes away. Unless you have a o-scope around then you can check the line for noise.

The lights have plugs. And I don't have an o-scope around. The lights are on a separate circuit from the radio. I also noticed, I loose my radio when I drive my pickup into the shop. So, I think the RFI is emitted through the air...my uneducated guess anyway.

The engineer with Atlas Lighting suggested Snap Choke Core from Radio Shack. I had already tried one on the electrical cord and one on each of the speaker wires, all placed near the radio. Maybe I do not have enough or placed them wrong. At $2.99 for two, I can try more, if any thinks that would work.

Thanks

 

[justsam]

First, to eliminate a line noise issue, use a battery powered radio and see if issue is better . You stated you "lose" your radio when you drive in to shop. Is that due to interference or due to lack of signal due to metal building? How does truck radio work without lights on but inside building?

In the RF world it is all about signal to noise ratio. You can have high interference IF you have an even higher signal level.

Sounds like you are getting interference on both AM and FM. The interference from your lights is typically one that impairs Amplitude Modulated (AM) signals. Is it any better on FM? If you have the same level of interference on both AM and FM, than the issue is past the detector portion of your receiver, and more in the amplifier section, which is typical of a power line induced interference.

An outside antenna may help, if the issue is in the RF portion, as opposed to the audio or amplifier portion of the radio. Again it gets back to signal to noise ratio, if you can get more signal you can tolerate more interference.

 

[bookman51]

First, to eliminate a line noise issue, use a battery powered radio and see if issue is better . You stated you "lose" your radio when you drive in to shop. Is that due to interference or due to lack of signal due to metal building? How does truck radio work without lights on but inside building?

In the RF world it is all about signal to noise ratio. You can have high interference IF you have an even higher signal level.

Sounds like you are getting interference on both AM and FM. The interference from your lights is typically one that impairs Amplitude Modulated (AM) signals. Is it any better on FM? If you have the same level of interference on both AM and FM, than the issue is past the detector portion of your receiver, and more in the amplifier section, which is typical of a power line induced interference.

An outside antenna may help, if the issue is in the RF portion, as opposed to the audio or amplifier portion of the radio. Again it gets back to signal to noise ratio, if you can get more signal you can tolerate more interference.

Let me see if I can respond in the order of your questions. I appreciate your help.

1) The signal does do down a bit when I drive my pickup into the building. However, I checked to make sure, and when I have my pick up radio on, I get decent reception until I turn the lights on. Then most stations turn to static.

2) I get interference on both AM and FM on the plug in radios. I have not checked AM on the pickup radio. Without the lights I pick up stations pretty well. With the lights on, I only pick up AM and FM stations within about 10 miles. With any other stations I get a lot of static...so much I cannot listen to them.

3) I was getting good reception until the lights were put in. I get good reception on AM and FM when the lights are off. Most stations turn to static with the lights on.

4) I got an e-mail back from an engineer at Atlas Lighting and he told me they only use the nonconsumer (commercial) ballasts in their lights. Unfortunately, the local distributor told me the lights would not affect my radio. So, here are the following options

a) Replacing the ballasts with consumer/residential ones, but probably not an option since Atlas does not use residential ballasts. Plus another day of electrician's time and the cost of renting a sissor lift for working 15 feet up is a chunk of change.

b) Replacing the lights, but probably not an option for the same reason above. Now I could try to hold the distributor's feet to the fire and maybe they would pay the bill, but I have to decide if it is worth the grief and ill-will.

c) Try a shielded coxial cable and remote FM antenna. Now, in checking, seems like I can get decent cable (from a TV satellite supplier) for 20 cents a foot. I do not know how signal might drop, but I have a hill behind my shop/garage and I could run the cable 50 feet up the hill to its top and put an FM receiver there. I don't know anything about FM receivers but it appears on the Internet they run $30-$40. I suppose I need a metal pole or something to hold it. I need to do some trenching later this summer so I could bury the cable at the same time. Looks like for some time and maybe $100 I could do an external antenna...if that would work. Never done one before, so cautions or additions to my plan. I suppose if I wanted to be hardnosed, I could ask the light distributor to come up with the money for the wiring and antenna.

Oh yes, my radios are cheap ones and I do not see place to connect a coxial cable. One is a boom box with a telescopring antenna, which might screw off. The other one just has a screw for an external antenna. However, I assume I need to disconnect any internal antenna or else it would pick up the RFI.

Thanks and I welcome any further help.

 

[bookman51]

First, to eliminate a line noise issue, use a battery powered radio and see if issue is better . You stated you "lose" your radio when you drive in to shop. Is that due to interference or due to lack of signal due to metal building? How does truck radio work without lights on but inside building?

In the RF world it is all about signal to noise ratio. You can have high interference IF you have an even higher signal level.

Sounds like you are getting interference on both AM and FM. The interference from your lights is typically one that impairs Amplitude Modulated (AM) signals. Is it any better on FM? If you have the same level of interference on both AM and FM, than the issue is past the detector portion of your receiver, and more in the amplifier section, which is typical of a power line induced interference.

An outside antenna may help, if the issue is in the RF portion, as opposed to the audio or amplifier portion of the radio. Again it gets back to signal to noise ratio, if you can get more signal you can tolerate more interference.

I put batteries in my radio and unplugged it from the power source. When I turned on the lights, I lost all but the closest AM and FM stations.

 

[darcyh]

I had the same problem after installing 'electronic' ballasts on my lights. These ballasts are really switching power supplies and are notorious for generating RF interference. Some ballasts do a better job than others at shielding the noise. I understand 'residential' ballasts do a better job at filtering out the noise.

I believe the RFI is emitted through the AC line as well as the ballast. I have had success by installing filters at the connection of the ballast. Mouser sells them for about $13. This is the only way I eliminated 90 percent of the noise.

Other option is to mount an outside antenna many feet away from the building and run co-ax cable to your receiver. This won't help much for AM reception.

To see the effect of a poorly shielded switching power supply, take a portable radio and place it near the 'brick' part of a laptop p/s an see what it does to your reception.

Good Luck

 

[bookman51]

I had the same problem after installing 'electronic' ballasts on my lights. These ballasts are really switching power supplies and are notorious for generating RF interference. Some ballasts do a better job than others at shielding the noise. I understand 'residential' ballasts do a better job at filtering out the noise.

I believe the RFI is emitted through the AC line as well as the ballast. I have had success by installing filters at the connection of the ballast. Mouser sells them for about $13. This is the only way I eliminated 90 percent of the noise.

Other option is to mount an outside antenna many feet away from the building and run co-ax cable to your receiver. This won't help much for AM reception.

To see the effect of a poorly shielded switching power supply, take a portable radio and place it near the 'brick' part of a laptop p/s an see what it does to your reception.

Good Luck

Thanks, I can live without AM but I do enjoy FM. I had 9 lights installed they are 15 feet up, so I had to rent a sissor lift. I don't look forward to purchasing 9 filters, renting a sissor lift and probably getting the electrician back. I will try the remove antenna first. Thanks for the suggestion.

 

[justsam]

Sorry to say but this is not going to be an easy problem to solve with the existing hardware, or labor revisiting the individual light fixtures.

You have an environment where it is difficult to get signal to the receivers due to the metal building, and you have the T-5 lights which are effective broadband noise generators inside the building. Depending on their proximity to the roof or other metal in the building, they can inductively couple RF into the building, using it as a giant antenna.

At best I think you can mitigate the issue by using magnetic ballasts as opposed to switching supplies, but the tubes themselves can at times be noise generators.

Getting more desired signal to your receiver is an option, but it needs to be a decent receiver with a coaxial antenna input, and an external antenna.

My fear is you can spend time, money, and frustration and only reduce the issue. I suggest you consider something like internet radio which most stations now have, Pandora or the like if for music, etc.

Remember if you do want to battle it, it is a two pronged approach, improve the desired signal, and reduce the interfering one, i.e. signal to noise ratio.

 

[raceman17]

I 2nd the internet radio...

I noticed I had the same problem with the FM radio when I moved into my new shop. I used my Iphone or any other smart phone and just use a radio app like Iheart Radio or Pandora. Most radios have inputs for these devices. It was the cheapest and easiest thing to do.

 

[bookman51]

"Getting more desired signal to your receiver is an option, but it needs to be a decent receiver with a coaxial antenna input, and an external antenna."

I think I will try this first since I don't have an internet radio, Ipod, or smart phone.

I do get some of the stronger nearby stations despite the lights, and during the day I don't have to run the lights...so I can get the other stations.


Thanks for the advice.

 

[bookman51]

I solved the problem with a remote antenna, shield coaxial cable from the antenna to the radio, a used stereo receiver, and putting the speaker wires in metal conduit. I have better sound in the shop than in the house.

 

[laser3kw]

thanks for the update. I am sure others are in the same boat and will find this usefull

 

[Scott I]

HI , i like the easy part of your idea. my question is how do you hook coaxial up to radio that has no port for coax. would an alligator clip work pinched on existing antenna of Milwaukee job shop radio?

 

[Milton Shaw]

I am amazed you can find anything on the radio you would want to listen too. I listen to mp3 player in shop and while on trips as I cannot find any stations with music I like.

 

[Stee6043]

I went through this same round of shock, denial and finally acceptance last summer when I installed a bunch of T8's in my garage (T5's aren't the only light with this issue). When my two circuits of lights are both switched on I believe I can receive 2 of my 12 radio station presets. And those two stations are not the two you'd want to listen to in the garage with a beer in your hand while doing anything remotely masculine in nature (which perhaps begs the question of why they are presets on MY garage radio....hmm).

After looking at the cost of the filters, the pain it would be for me to mount an external antenna and the overall investment in either I finally accepted the reality that I put way too many lights in my garage to expect any kind of normal radio reception.

If I'm in my garage with the overhead lights on the stereo is either playing mp3's or streaming Pandora from my phone. This is the reality for me in a well lit garage. And I'd say it's 100% worth it.

 

[2ManyProjects]

HI , i like the easy part of your idea. my question is how do you hook coaxial up to radio that has no port for coax. would an alligator clip work pinched on existing antenna of Milwaukee job shop radio?

First, note that the coax itself will NOT act as an antenna (well, not a good one, anyway). Avoiding pickup of "interference" signals is precisely the point of the shielded cable design. That coax will need to connect to a usefully oriented REAL antenna in order to do you any good.

If the unit has screw-type antenna terminals, but NOT a coax antenna input, use a "Balun" transformer, such as:

http://www.solidsignal.com/pview.asp?p=wmxfmrpt&d=pigtail-300-to-75-ohm-transformer-/-balun-(pvmt2)

.

But it sounds like your radio lacks even those terminals.

When it comes to jury-rigged ad hoc antennas for radios not designed to use an external antenna, it becomes almost purely a matter of trial & error dumb luck. Pretty much ANYTHING you rig up will be "wrong" in theory; but may actually provide some degree of practical improvement depending on what particular reception issue you're battling. That said, if you're just going to alligator-clip it to a rod-type antenna, don't use coax; use ONE clip, and a single-conductor wire of some sort. Orientation and length of that wire will become the critical variables.

But really... You're near-certainly asking for too much out of too little underlying hardware. Portable "boom box" radios are fine for job sites. But for a permanent installation in your shop/garage, you really ought to do better, for all sorts of reasons (radio reception being only one of them). This does NOT mean you need to spend a ton of money. Craigslist is rife with old two-channel stereo receivers, many of which can be bought for perhaps $20-50 (and at least most of the ones with significantly higher asking prices are still only worth $20-50, despite the sellers' often silly B.S. prose about "vintage audio" or similar nonsense; '70s/'80s Japanese Mid-Fi is still just '70s/'80s Japanese Mid-Fi, and at least most of it was mediocre at best even back then). Find a modest pair of bookshelf speakers you happen to like for another $20-50 or so (be sure the woofer surrounds are in good shape; old foam ones tend to rot away over time), and you're good to go.