USB Charger Causing Radio Interference -RFI (1 Viewer)

Titanium

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Had very bad interference on the truck 2 meter rig last weekend while camping with the cab over camper. The receiver S meter was displaying full strength noise when the truck was within 25' of the camper or connected. The receiver had very poor reception and only could copy the strongest repeaters.

I thought that the problem was the solar PWM controller or LED lights, but was surprised when the culprit was found to be the USB charger!

Here is a YouTube video on the problem and resolution. If you notice noise in your stereo or ham radio, check if the USB charger is the source. This seems to be a very common problem that no one talks about.

 

primestar31

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I had a noisy Dell laptop charger brick, and a noisy Harbor Freight battery maintainer that were both destroying my VHF tv reception before I tracked them down. I could pick up the HF charger almost 300 feet away from my garage on the AM radio in my car.

Many manufacturers no longer take any steps for filtering or shielding switching power supplies.
 
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Corrado

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Over the years I had purchased dozens of LED bulbs for the house to replace the CFLs and incandescent bulbs, I found many of the earlier ones generated so much RFI that it wiped out the OTA TV stations. Those ended up in the garage, attic and closets and other barely used places.

More recently, I noticed something about to become an issue for amateur radio HF users. A home down the hill from me recently had solar panels installed. During daylight hours there is a definite inverter whine present on AM. I can't be 100% sure, but it started the same time and is noticeable even on a car radio when driving by.
 
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nbkhwjm

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Had very bad interference on the truck 2 meter rig last weekend while camping with the cab over camper. The receiver S meter was displaying full strength noise when the truck was within 25' of the camper or connected. The receiver had very poor reception and only could copy the strongest repeaters.

I thought that the problem was the solar PWM controller or LED lights, but was surprised when the culprit was found to be the USB charger!

Here is a YouTube video on the problem and resolution. If you notice noise in your stereo or ham radio, check if the USB charger is the source. This seems to be a very common problem that no one talks about.


ive had those cig chargers full up BLANK OUT strong FM stations in the car.. they are awful.. absolute crap...
 
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wvman

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Has anyone experienced similar problems with the ever so common wall warts that come with everything these days? I have a ton of those things running in my house. I have some interference on my cameras hooked to my security system. I have tried everything to track it down and can't locate the problem.
 

primestar31

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Has anyone experienced similar problems with the ever so common wall warts that come with everything these days? I have a ton of those things running in my house. I have some interference on my cameras hooked to my security system. I have tried everything to track it down and can't locate the problem.

Yes, very much so. Switching power supplies are the Devil.

How have you noticed the issue? Is it coming through on a tv set, or radios, etc? shut off ALL your breakers (except main one). Turn on ONLY the one feeding that device, and see what happens. IF you notice the interference right away, find out what all is plugged into that circuit, and disconnect them one by one until the interference stops. If you don't notice the interference right away, turn on each breaker one at a time until you do.

There also is the possibility that the interference is coming from a power pole, or neighbor.
 
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KE4EST

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Yes, those cheap things are more headaches sometimes then help.
 

harshness

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Yes, very much so. Switching power supplies are the Devil.
There's an interesting manual quote in a recent Jay Allen radio review about Sangean's switching wall warts used in a couple of their tabletop radios and how they don't seem to cause interference. Search for the phrase "VERY IMPORTANT PLEASE READ".

If someone is going to the trouble and expense of avoiding these issues, they should be recognized.
 
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wvman

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Yes, very much so. Switching power supplies are the Devil.

How have you noticed the issue? Is it coming through on a tv set, or radios, etc? shut off ALL your breakers (except main one). Turn on ONLY the one feeding that device, and see what happens. IF you notice the interference right away, find out what all is plugged into that circuit, and disconnect them one by one until the interference stops. If you don't notice the interference right away, turn on each breaker one at a time until you do.

There also is the possibility that the interference is coming from a power pole, or neighbor.

The only place I've noticed any interference is on my cameras for my security system. I bought a new power supply, still there. I had a voltage conditioner and powered the cameras through it, still there. I bought individual wall warts designed for use with cameras, still there. Purchased ground loop isolators, made the problem worse. I bonded all the grounds on the house, still there, only now, it's intermittent, and switches cameras. I am beginning to wonder if the cameras aren't talking to each other.

All my cameras are TVI, but none of the cameras are on cable runs longer than a couple hundred feet, even though TVI can function out to 1400 feet. Being somewhat of a perfectionist, I get annoyed rather easily when I can't solve problems like this. The power out here really sucks since First Energy took over. I've spoke with their linemen and they are frustrated as hell because they won't let them spend the money necessary to remedy the problem. No high speed internet, bad electric grid, poor phone and cell service.

We live in electronic hell? :)
 

wvman

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Yes... lots of times.

I am sure radio from WION Radio can tell you some stories about these beasts!

I have 3 very expensive surge protectors mounted in a cabinet near my cameras, and all three are filled with wall warts running my cameras. Since these are running cameras, they are supposed to be filtered and regulated to avoid such problems, but who knows. You're at the mercy of the person you bought them from. I have 2, 32 slot camera power supplies, but the problem is worse using them. May end up being a problem I'll have to get used to having.
 

primestar31

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The only place I've noticed any interference is on my cameras for my security system. I bought a new power supply, still there. I had a voltage conditioner and powered the cameras through it, still there. I bought individual wall warts designed for use with cameras, still there. Purchased ground loop isolators, made the problem worse. I bonded all the grounds on the house, still there, only now, it's intermittent, and switches cameras. I am beginning to wonder if the cameras aren't talking to each other.

All my cameras are TVI, but none of the cameras are on cable runs longer than a couple hundred feet, even though TVI can function out to 1400 feet. Being somewhat of a perfectionist, I get annoyed rather easily when I can't solve problems like this. The power out here really sucks since First Energy took over. I've spoke with their linemen and they are frustrated as hell because they won't let them spend the money necessary to remedy the problem. No high speed internet, bad electric grid, poor phone and cell service.

We live in electronic hell? :)

Pretty much, yeah. Try a true sinewave UPS.

Did you check your houses ground rod by the electrical panel, to make SURE the ground wire didn't disconnect from it (or from the panel side)? I have had that happen at a house we used to own.

If it is still connected, maybe try cranking it tighter with a wrench, or throw several pails of water on it to soak the ground. Then see if that made a difference. If so, get another ground rod, pound it into the ground fairly close by, and bond both of them together with a heavy gauge piece of copper wire. Do NOT disconnect the first one and transfer the wire as that could be dangerous in certain cases.
 

harshness

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All my cameras are TVI, but none of the cameras are on cable runs longer than a couple hundred feet, even though TVI can function out to 1400 feet.
This is why IP cameras and NVRs are quickly taking over (not for the 1,400' foot part, but the freedom from the many forms of analog interference).
 

wvman

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This is why IP cameras and NVRs are quickly taking over (not for the 1,400' foot part, but the freedom from the many forms of analog interference).

IP cameras are not without their problems. A friend of mine sells security cameras, and he went over the pros and cons of IP systems. Ne put one in at his house, and didn't like it. He had 3 customers swap their out for a TVI system. I guess everything has its quirks.
 

Cham

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If using IP cameras make sure you are using shielded (stp) cat cable. I use just about 100% shielded cable now to keep interference to a minimum... Saves NIC boards from RF overload when running a few KW on 80m too.

I have had a few of those cheap wall wart switching power supplies go bad and make a lot of noise... Too bad they have such a variety of voltages for the different devices these days, would have more spares if they needed 12vdc.
 
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spongella

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Have read that the FCC has been investigating solar panel interference and issued violations to Solar City. You should register a complaint and it might be resolved. Here is a link for information: FCC issues a Notice of Violation to Solar City for RFI Inteferance

As a former Health Inspector for our county we've also gotten a few complaints by residents living near solar farms about noise being generated, and we've found that the inverters during the duty cycle generate noise from the cooling fans, but the decibel level is below our state's maximum (65 dbA daytime, 50 dBA nights). Several of these farms have been built here over the last few years, glad to see them vs. another high-end housing development hi hi.
 
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Magic Static

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We have a bitcoin server farm that went up in an old lumber mill site. The cooling fans make a horrible noise that is heard all over the area. While it actually makes less noise than the mill did during it's years of operation, it is flat annoying.
 
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