Weirdest interference sound on AM I've ever heard

[FreddyE1977]

After noticing that ANY station gets blown off my AM car radio for about a block in either
direction around a certain house in my neighborhood.....I have investigated and learned that
hydroponic marijuana growing operations can produce this sort of interference.

 

[boiseengineer]

You could offer to put RFI filters on their lamps for them.

 

[kenglish]

I can't do much of any AM DXing in my apartment now.

For the last few months, there is this buzzing sound that sounds like what you hear from a fluorescent light which starts up every 45 seconds and lasts for about 15 seconds.

It's non stop day and night.

It's so annoying and I can't imagine what it could be.

I'd vote for Doorbell Transformer....a stuck button (or shorted wiring to the button), will cause the transformer to overheat (it's only designed to operate for a few seconds at a time), so there is a thermal cutout built into the transformer itself. As it heats, the cutout disconnects the circuit, then (as it cools) it reconnects. Since they are just cruddy contacts on a bi-metal strip, they arc like crazy.

The other possibility is bad wiring, which is much more serious. Outdoor lights, with buried NON-Burial rated cables, do that a lot. The power company should probably be called, so their RFI-Guy can come check it out.

 

[kinphoenix2]

I listened to the "weird" sound poster uploaded and for the life of me can't place it but it sure sounds familiar. OK- he states it affects an entire block area - so I doubt it's hydroponic lights. The "screech" sound in the audio file makes me think it's digital type (ethernet) IF.. BUT- that wouldn't reach an entire block out. Hmm.. the only thing I've seen my SELF that can reach that far is A) bad GND on pole (but doesn't sound like his audio file at all)
our metro light rail train makes MW sound super weird when it goes by and it affects an entire city block.

Anyone else care to listen to that audio file for their two cents lol

 

[kenglish]

That sound on his video, at 610 KHz, sounds exactly what I get on 610 here in Utah. It seems to be all over the building, but barely there at all in the parking lot.
I also hear a station under it sometimes....maybe a beat between two stations on 610, with some modulation-level related FM'ing of one or the others carrier?

 

[gar hi]

I can't do much of any AM DXing in my apartment now.

For the last few months, there is this buzzing sound that sounds like what you hear from a fluorescent light which starts up every 45 seconds and lasts for about 15 seconds.

It's non stop day and night.

It's so annoying and I can't imagine what it could be.

I'd vote for Doorbell Transformer....a stuck button (or shorted wiring to the button), will cause the transformer to overheat (it's only designed to operate for a few seconds at a time), so there is a thermal cutout built into the transformer itself. As it heats, the cutout disconnects the circuit, then (as it cools) it reconnects. Since they are just cruddy contacts on a bi-metal strip, they arc like crazy.

The other possibility is bad wiring, which is much more serious. Outdoor lights, with buried NON-Burial rated cables, do that a lot. The power company should probably be called, so their RFI-Guy can come check it out.

After reading your post, I figured out what it is!! THank you.

I don't know why it didn't hit me sooner.

Whenever I sit out on my porch at night, I notice there's a light in the porch area of the 2nd floor apartment next to me that goes on for a short time, goes off, and then goes on in the same exact time cycle.

I can't see the light directly from my porch but the light it sheds going on and off is noticeable.

So I went out to where I can see the light doing this and see it's defective.

Now I don't know how to ask the landlord about fixing it. The light isn't completely out, so I don't know if they would care about it.

Or do I simply be honest and tell them the reason I request the light to be fixed? ;D

Since most people aren't into DXing, they may think I'm weird.

 

[boiseengineer]

Tell them their light is defective and is emitting lots of RF radiation. They need to replace it immediately!

 

[boombox]

You could also remind them of the safety issue, that when the light goes off, it creates an unsafe situation for residents.

 

[tomservo]

A cycling light like that is one of those things I might not notice… until I do, then it would bug the crap out of me until I got someone to fix it.

A couple of towns north of here they replaced all the old street lights with these new LED deals. They look fantastic and emit a very clean light (and seem to cause no new interference on AM) but they constantly go on, and off, and on, and off… I thought new technology would have fixed that problem by now. When I'm stuck in traffic or at a red light I notice them going on and off and they drive me crazy.

 

[kenglish]

The local Cable TV company had interference on several of their head-end's satellite dishes a few years back. It was coming in on the L-Band RF cables, and causing noise in the (at that time) analog satellite TV channels.

It was one of those outdoor lights that comes on at dark, and off at dawn.
Not uncommon............. .

One thing I have used, is to tell people that the cycling on and off uses a lot more electricity than a properly functioning light.
That often gets their attention.
Also, anything arc'ing is a fire hazard. The fast-food place next door to me had a broken neon tube in their rooftop sign, due to a windstorm. It was arcing like crazy.
Unfortunately, the owner tried to fix it himself, and burned the building down.

 

[kenglish]

After noticing that ANY station gets blown off my AM car radio for about a block in either
direction around a certain house in my neighborhood.....I have investigated and learned that
hydroponic marijuana growing operations can produce this sort of interference.

Tack this on his door, and RUN:
http://transition.fcc.gov/eb/AmateurActions/files/Grow_11_09_30_5275.pdf

"The Federal Communications Commission has received a complaint of harmful
radio interference that is apparently caused by a grow light ballast being
operated from your residence. This interference has been reported by a
licensed operator in the Amateur Radio Service."

 

[kenglish]

Tell them their light is defective and is emitting lots of RF radiation. They need to replace it immediately!

Show them this letter:
http://transition.fcc.gov/eb/AmateurActions/files/Light12_04_10_5310.pdf

"The Federal Communications Commission has received a complaint of harmful
radio interference that is apparently caused by a light being operated at
(address withheld). This interference has been reported by a licensed
operator in the Amateur Radio Service. "

 

[kinphoenix2]

I can't do much of any AM DXing in my apartment now.

For the last few months, there is this buzzing sound that sounds like what you hear from a fluorescent light which starts up every 45 seconds and lasts for about 15 seconds.

It's non stop day and night.

It's so annoying and I can't imagine what it could be.

I'd vote for Doorbell Transformer....a stuck button (or shorted wiring to the button), will cause the transformer to overheat (it's only designed to operate for a few seconds at a time), so there is a thermal cutout built into the transformer itself. As it heats, the cutout disconnects the circuit, then (as it cools) it reconnects. Since they are just cruddy contacts on a bi-metal strip, they arc like crazy.

The other possibility is bad wiring, which is much more serious. Outdoor lights, with buried NON-Burial rated cables, do that a lot. The power company should probably be called, so their RFI-Guy can come check it out.

After reading your post, I figured out what it is!! THank you.

I don't know why it didn't hit me sooner.

Whenever I sit out on my porch at night, I notice there's a light in the porch area of the 2nd floor apartment next to me that goes on for a short time, goes off, and then goes on in the same exact time cycle.

I can't see the light directly from my porch but the light it sheds going on and off is noticeable.

So I went out to where I can see the light doing this and see it's defective.

Now I don't know how to ask the landlord about fixing it. The light isn't completely out, so I don't know if they would care about it.

Or do I simply be honest and tell them the reason I request the light to be fixed? ;D

Since most people aren't into DXing, they may think I'm weird.

Nope, they won't think you're weird- most non-radio people hear words like "shortwave" or "dxing" & assume "ham" is synonymous, so you'll get respect that way

I had a similar rotten lights experience recently moving into this condo unit, loud buzzzz- did a quick RF hunt with AM portable found it coming from a non-working fluorescent plastic housing lamp cheapest p.o.s. and to top it off it was hard wired, above the kitchen sink- NO ground- NO GFI, and was giving off extreme interference even tho it was powered off (hot wired) can you believe? What idiots installed it THAT way? Knowing my landlord, probably had the undocumented gardener/"electrician" do it (i fix, now u have lite, see?) I cussed and ranted and had the landlord come and rip that out.

Electrician coming tomorrow, gonna show him my non-GFI areas and see what can be done about a ground around here. Ugh- nothing I hate more in a living space than bad wiring.

Hope your noise issue is gone for good! and to who posted the FCC "complaint" form that is awesome. Gonna print some out for "reference" later ha ha.

 

[gar hi]

I finally mentioned something to them today and I probably would not have been able to otherwise but I had to call the office to tell them that someone let their dog take a huge poop right outside my apartment and I almost stepped in it.

Since they said they were sorry and said they would take care of it, I thought I would take the opportunity to tell them about the defective light as well.

I felt kind of awkward explaining why I wanted the light fixed but the person at the office was really nice about it and said she would put in a maintenance request.

It's still not fixed as of tonight but it may take a day or two.

I've had to pretty much miss a lot of AM DXing this season because I couldn't figure out where that constant buzzing was coming from.

 

[kenglish]

My stove had a range hood above it, and both were about four feet from the metal kitchen sink.
I was doing some RFI work around the apartment one day, and measured the voltage between the range hood and the stove and sink.....with the fan operating, there was 60+ volts between the range hood and ground!
After turning off the breaker and checking things out, it appeared that the installer didn't have a six-inch piece of bare copper wire (and, I guess he didn't have wire strippers), to connect to the green screw.
It's there now, though...courtesy of the local broadcast engineer/DX'er.

I'm debating whether the reversed ground and neutral on the downstairs sprinkler timer is a problem or not.
With the LED TV sets, and the "energy-efficient" outside lights, it may not be worth bothering.

 

[boiseengineer]

I would fix that ASAP.

 

[kinphoenix2]

I finally mentioned something to them today and I probably would not have been able to otherwise but I had to call the office to tell them that someone let their dog take a huge poop right outside my apartment and I almost stepped in it.

Since they said they were sorry and said they would take care of it, I thought I would take the opportunity to tell them about the defective light as well.

I felt kind of awkward explaining why I wanted the light fixed but the person at the office was really nice about it and said she would put in a maintenance request.

It's still not fixed as of tonight but it may take a day or two.

I've had to pretty much miss a lot of AM DXing this season because I couldn't figure out where that constant buzzing was coming from.

You wouldn't happen to be living in the same condo complex as I am, are you?? lololol

 

[gar hi]

I swear, talk about luck.

They finally fixed the outdoor light near me that I mentioned that was making the on and off buzzing sound at the same intervals and I managed to get about a week or so of much missed nighttime AM DXing in.

Wouldn't you know it, there's now a constant buzzing sound that I've never heard. I first noticed it early this afternoon and it's still going on. It sounds like the kind of sound a fluorescent light would make but I can't imagine my next door neighbor leaving their kitchen ceiling light on for so long.


It's so frustrating.

 

[Tom Wells]

I swear, talk about luck.

They finally fixed the outdoor light near me that I mentioned that was making the on and off buzzing sound at the same intervals and I managed to get about a week or so of much missed nighttime AM DXing in.

Wouldn't you know it, there's now a constant buzzing sound that I've never heard. I first noticed it early this afternoon and it's still going on. It sounds like the kind of sound a fluorescent light would make but I can't imagine my next door neighbor leaving their kitchen ceiling light on for so long.


It's so frustrating.

The "new" noise may have been there already, but not audible due the noise from the outdoor light.

Almost every cheap automatic on@dusk/off@dawn photocell light timer leaks a "buzz" current all day long.

The reason is that they drive the AC load (the lamp) with a semiconductor "switch" that never quite turns all the way off.

"On", Is sometimes 100 percent duty cycle of the AC sine wave, and the device no longer emits RF, but some always buzz whether on OR off.

"Off" is not really 0% conduction on such devices. Even though there is only .01 per cent conduction time, the lamp is effectively off.

The device still works all the time as an rf wideband 60 hz buzzer, ready to modulate and annoy almost all frequencies equally.

This is beacuse the product of a square wave modulation is spread spectrum. Fortunately it does not go far.

Too darn bad such designs were not required to operate a real honest to god RELAY, which would make one brief click at operation.

Walk around with a little AM portable to see if you can figure out the direction.

Is it the same day/night ?


Here's a likely maybe:

I suspect someone has a switch operated outside light socket, and they've put a small daylight automatic screw-in lamp controller.

When you don't hear the noise, they have the switch inside turned off.

When they want the automatic lamp to work they leave it switched on.

It may be some tiny bad connection at a neighbor's AC socket where any kind of switching power supply is connected.
Multiply by number and proximity of neighbors.