electronic interfereence

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rickf

Well-known member
Joined
Jul 26, 2010
Posts
85
Hi,
just nput in two led bulbs in the light over the dinette.
this now interferes with the TV on some channels,
mainly one the wife likes the evening programming,
so this is not good.  anyone else have this problem
and resolved it?
the tv is with a digital antenna, new this year.
thanks
 

Jim Godward

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Mar 6, 2005
Posts
5,906
Location
Hillsboro, Oregon
Welcome to the wonderful world of Radio Frequency Interference, RFI.  There have been a number of cautions in the amateur radio sites regarding this problem.  It is real and a real nusance to say the least.  Solutions, none have been specifically identified.  However depending on the nature of your particular proble and your skill in electronics, there some things to try.  The easiest is to replace the LEDs with the original bulbs.  That will solve the SWMBO issue.

Then contact the place where you bought the lights and try to exchange them for others that do not have the problem.  You may just get you money back or they may have LEDs that do not have the problem.  How will you know, trial and error.

The problem arises because of the circuitry that is required to keep the LEDs happy with the applied voltage.  There is probably some high frequency switching going on and this results in local noise.  The FCC will be of no use to you as the issue is with the owner and user, you, of a noise generating device and not the manufacturer thus it is up to you to reduce and/or prevent the interference

It is sort of blackmagic to solve the problem if you choose to keep and use the LEDs.  Ferrite beads on the light fixture wiring as close to it as possible, may help.  A 10 microfarad capacitor across the lines of the light might help.  Ferrite beads on the input power lines to the TV may help.  These ideas are just a start and may not work at all. 

Unless you are knowledgeable in electronics either stay with the original bulbs or find a source of LEDs who will and can provide LEDs that do not interfere.  They will be expensive!!!!  :(

The only positive solution I can mention at this time is replace the LEDs with the original bulbs.  That will solve the SWMBO issue.
 

Gary RV_Wizard

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Feb 2, 2005
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73,954
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At our Silver Springs FL home
There is no inherent reason that leds themselves would generate RFI, so the ones you have must crappy supporting circuitry.  My best advice is to return them and exchange for another, better quality brand.  If you got them from forum-advertiser rvledbulbs.com, I'm confident they will exchange them for a another brand (I prefer Revolution or Ming for quality leds) or refund your money.

Here is another thought: were the bulbs that were replaced by the leds incandescent or fluorescent?  If incandescent, I'm wondering if the load from the bulbs was actually filtering out the noise in the circuit and now the lack of load by the leds is letting it pass through to the tv. And if fluorescent, did you remove the power from the ballast when installing the leds? If not, it is probably the unloaded ballast that is making the RFI noise.
 

John From Detroit

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Joined
Apr 12, 2005
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24,948
Location
Davison Michigan
Gary RV Roamer said:
There is no inherent reason that leds themselves would generate RFI,

Actually.... There is,  LED's naturally generate a very wide range of frequencies,  In another time I had a friend, T.E.Hartson who along with Walt Wilson wrote an article for a magazine I happen to subscribe to.  The article was a construction project, a "Gated noise source".. This is a device that spits out a very very broad spectrum electronic noise.. If you gate it (Turn it on and off at audio frequencies) and feed it to an AM radio you hear the audio (Gating) Frequency,  You turn around the band, the tone does not change  It never gets louder or softer.. You change bands, the tone is still there.. The unit described in the article was "FLAT' (That is the output was consistant) from around CB frequencies to MICROWAVE  Ted (T stands for Ted) used it to tune up the receivers at the cable vision company he worked for, as well as his ham gear.

The noise generating device was a diode,, All diodes do this, (Generate noise) the trick is to control the diode's noise.

I built one using LEDs.. Did not work as well as Ted's but there were several compromises in my design.  I will fix that one day.

Now to the original poster....

There is something called a Disc Ceramic Capicator, Radio shack sells them in the parts drawer.  Pick a few in the .1 .01, .001 range, wire them in praallel and wire them across the leads on the LED, the closer to the LED's you can put 'em the better,  they absorb RF enegery  I'm not sure which one will do you the most good but if you should try assorted powers of 10 till you get lucky, they are low cost .

 

rickf

Well-known member
Joined
Jul 26, 2010
Posts
85
wow,  getting a little above me on this.  I was reading that some diode type
used in leds to allow a range  of voltage, like from 10 to 18 volts, can cause this.
I was reading this on an offshoot site of a guy called the prudent rver.
anyway, I ordered  a couple bulbs from the RVLED site here, and he also said
that only once had he experienced this.  the bulbs I bought, from TechnoRV.com
are not a problem except the fixtures nearest to the TV.  so I can use them in another location.
Gary, the people at RVledbulbs,  Brian and Jay, seem great. I called and they set up different
shipping, honored the advertised discount, and shipped immediately.

Rick
 

Gary RV_Wizard

Site Team
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Feb 2, 2005
Posts
73,954
Location
At our Silver Springs FL home
Glad to hear the guys at rvledbulbs.com (aka Hitching Post of Ocala) are treating you right, Rick. I've done business with them myself for many years and always been treated very well, but it is good to hear positive feedback from others.
 
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