In house AM Radio Interference during the day that disappears at night?
 

Greetings everyone, I like to listen to AM Radio to listen to various talkshows and also old time radio shows (Classic Radio Theater with Wyatt Cox.)

When I try to listen to some of the "local" 50kW radio stations out of places like Fort Wayne, Indiana (WOWO 1190 AM), Chicago (WLS 890 AM), Detroit (WJR 760 AM), or Cincinatti (WLW 700 AM) during the day I hear a horribly loud and annoying "Brrrrzzzz" noise/interference, that is so powerful that it basically knocks every strong "local" 50kW station off the air on all of my radios (it is most noticeable on the upper portion of the AM Band between 900 kHz and 1500 kHz and its very directional and seems to be originating from a specific spot in my basement that doesn't have anything electrical or electronic that could emit any sort of electronic interference.

The weird part about this interference is that its of a radiated type of interference because it also affects my battery operated radios, and another weird part about this intereference is that it only happens during the daylight hours, but during the night time hours the interference is completely gone, and it has only been happening for 2 weeks prior to two weeks ago I had no issues with this aforementioned interference issue.

Anyone have any ideas as to what this weird interference might be, and why it only happens during the daytime hours and not during the night time hours?

Today, with all those modern appliances with switching devices/PSU/inverters etc, is more difficult to find one culprit. It can be various devices on at same time, in a near vicinity.
Solar power plant or a small industry with bad motor inverters or factory lightning come to mind, if is only at day. Staff can be changed equipment to bad ones at this time frame, perhaps... or a new enterprise nearby.
The good equipment of course have EMI mitigations, but is sure that various devices don't have any or seems to not have (or have lousy filters/PCB layout). A friend of mine loves to listen radio, and even at FM, certain devices plays havoc: he needs to switch off all LED lightning at his mechanical workshop to reduce noise, and one LED spotlight simply kills his preferred FM station...
Perhaps, with a less sensitive portable radio, you can find the direction of harm signal, to have a chance to find the culprit.

One way to check if it's you or something in the neighborhood is to use a battery portable, and turn off the main breaker for a minute. If the noise stops it's probably you, it it persists it's probably neighbors. If it's you turn main back on and individually cycle the other breakers till the noise stops then figure out what the breaker that kills it powers and unplug that stuff one by one till you figure out the source.
Just basic troubleshooting.

Hmm, well the strange thing is that I have tried that and the noise doesn't go away, and I live in a strictly residential neighborhood so no industries near by to create interference and I only have one neighbor that lives close enough to me to be able to have any sort of effect on my house and the weird thing is that when I use my battery powered radio the further away from the center of the house I go the better the reception gets (the interference goes away).

When I used my battery radio to try and trace the interference down in my house the interference is worse in the basement in a small 1 cubic foot area of my basement that is near the floor drain in the basement, and in front of where my water heater and furnace sits and in front of where my utility sink for my washer and dryer sits, and as far as I know there is nothing in that area that has a switchmode power supply that can create any sort of interference. The weird thing is that my tube radios are affected the worst by the interference than my solid state radios are...

The only other thing I can think of is that perhaps there is a radon gas leak in my basement that might be causing an issue? I know that from what I read radon gas is more prevalent during the day and less prevalent during the evening and night time hours, and is completely dependant on the sun.
Since radon is a natural byproduct of uranium decay is it possible that my radios are acting like geiger counters or like a radon detector of sorts?

"is it possible that my radios are acting like geiger counters or like a radon detector of sorts?" No.

Is the sound continuous , or repeating?
You said you tried "that." Do you mean you shut off the whole house at the electrical box?

Do you have an electric water heater, or gas?
If electric, is the power on a special circuit that controls usage by time of day?
Does the interference disappear all night or come back in the early hours?

Another thought could you have a smart water or gas meter that reads regardless of the electric utility...Those smart meters do transmit.

Yes, but all day? And if it's the meter, it should be possible to detect that by taking the portable radio next to it.

The clues so far are not adding up.

Note that you can rotate the portable radio to try finding a null that points at the interference source.
https://www.electronics-notes.com/ar...s-tutorial.php

The sound is continous. and when I said I tried that I was referring to turning off the main breaker and turning on the main breaker.

i have a gas water heater, and as far as I know it has its own breaker, but its alway on (no timer or time control.)

I do have a smart meter for my water, but it doesn't emit any noise because I thought of that myself and when I put my radio upto it it didn't do anything, as for my gas meter, it too is a smart meter, but it doesn't do anything either when I hold the radio up to it, the only things around the house that makes any major noise is my refrigerator and stove, but you have to be right ontop of them with the radio to hear anything, but I wouldn't think that the stove and refrigerator would make any difference between night and day as far as what kind of RFI/EMI noise it puts out, unless the refrigerator and stove is backfeeding the noise through the house's wiring?

The refrigerator is actually the only appliance in my house that I have found that comes closest to producing the same RFI/EMI interference that my radio is picking up, but I didn't realize refrigerators were capable of putting out RFI and EMI noise, because I wouldn't of thought of a refrigerator as having a SMPS in it, but that doesn't explain why I am hearing the noise strongly in the basement in just one spot, and why the noise goes away at night.

The refrigerator or stove doesn't make any sense with a difference between day and night that you have diescribed.

The only things that run according to time of day I can think of are heating and A/C and possibly an electric water heater if it's on a utility-controlled circuit for time of day control.

Can't think what else could be to blame.

Is the time of start and stop pretty reliable, or does it vary from day to day?

“Local” stations ???? :scratch2:

According to Radio Locater, all of the stations mentioned are some distance from Elkhart.

WOWO Ft Wayne - 57 miles
WLS Chicago- 97 miles
WJR Detroit - 145 miles
WLW Cincinnati - 182 miles

https://radio-locator.com/cgi-bin/lo...req=&sort=freq

I would be surprised if any of these would be static free during daytime but they would be stronger at night.

jr

Another thing to consider is that the area where the interference seems loudest could just be the area where the radio signals are weakest. (Still doesn't identify the source of interference, though.)

I wouldn't expect those stations to be strong in Elkhart anytime. They are too far away to be good in the daytime, except perhaps WOWO, and too close to be great at night. Certainly not what could be considered "local".

1. See if your electric utility meter is close by, "smart" meters make harmonics and hash within a few feet. A demand control may be time of day based, which would explain your symptoms.


2. Try looking at any outdoor light fixture nearby that comes on automatically at night.

Streetlights could be the source as controls regulating line voltages are placed in convenient, shrinking and increasingly weather-exposed packages. I have found few residential controls that last more than a few years but most DO go very erratic and noisy before a final failure to light again.

DC to LED's gets dicey once those cheap materials get wet. Try to pinpoint when the "sundown" point occurs, so you can scout around outside and see what went on.

The circuits that used larger cadmium sulfide photocells didn't have more than a simple triac to latch them on. Those older type photocells that dont "close" right away can make mercury lights noisy and flicker like something diabolically employed in a David Lynch movie.

I bet if you try a radio with an S meter it will read under nine
daytime & almost pin the needle at night. All the stations you listed are
50 KW probably ND clears. Without QRM easily listenable at 150 miles
day time on a GOOD radio. You are in an almost dead spot. Too close
but to far...
SO its probably a combination of QRM, distance & propagation.

73 Zeno:smoke:
LFOD !

Well I figured out what one of the sources of the interference was, it was my battery charger for my battery powered vacuum cleaner, when I left it plugged in after recharging the battery for my vacuum the charger apparently stayed powered on just enough to emit that aforementioned noise I talked about.

I actually took apart that charger and tested all of the electrolytics in it and they all measured 20+ Ohms ESR so then I replaced all but two of them because I accidentally ordered the wrong type of capacitors for two of them (I ordered surface mounted rather than PC Pin type capacitors.)

Also another one of the noise makers in my place was my nightlights that have the photocells on them so that they turn off at dawn and and turn on at dusk, apparently incandescent nightlights with dawn-to-dusk sensors on them put out some interference as well.

As for the distance those stations are from me and how good they come in, WLS, and WOWO both come in really well all day, but then WOWO actually shifts their transmitter signal in the evening from west to east so then at night WOWO doesn't come in as well in the evening/late night hours, but WJR, WLW and KXEL all come in great in the evening which is mainly when I listen to those stations, I guess I should of made that clearer.

I recently tracked a very bad buzzing problem to a bad transformer on my oil burner. When it was replaced, the loudest of the buzzing went away. However, I am also eyeing my doorbell transformer and a wall wort that charges the alarm system battery for replacement.

We found bad door bell transformers a few times. Just unhook the
primary to test. Same with ANY wall warts.
Not having a door bell can be a blessing. Out hear in the woods its either a JW or frozen meat salesman. Just tell the JW's to put you on the no call list & the meat man you are a herbivore ! Last type of "guests" are casing the joint. They see a riding mower etc & knock on the door. If no answer the goods go
into a beat up PU truck. Not much more crime here but DUI's & wife
beaters. The bad guys from the city know 80% have CCW's are better armed
than the Green Berets so go to Massatoosets :thmbsp:

Zeno:smoke:
LFOD !

Try Google

solar panel rf interference

My house does have a doorbell that is actually utilizing its original doorbell transformer yet from 1921 (in other words a 103 year old doorbell transformer) and the original doorbell is still working yet, and its one of those "gong style" doorbells that sound like the doorbell on "I Love Lucy", interesting thing is that the original doorbell transformer to my house doesn't put out any sort of interference whatsoever.

I have to have my doorbell because with me working 3rd shift and the fact that I have people come to my place to drop off and pick up electronics that I've repaired or will be repairing for them I need a way to hear if someone is at my door because otherwise I won't know if anyone is at my door, because I'm a heavy sleeper and also if I'm working on a repair job in my basement where my workshop is at, I can't hear if someone is at my door unless they ring the doorbell which the doorbell itself is in my kitchen which is in the back of the house and my basement entrance is off the kitchen, so I can hear if the doorbell is ringing or not which tells me if someone is at the door.

OK, so for all of you wondering what kind of radio I'm utilizing that I'm able to pull in all of the stations I mentioned as well as I do, I'm listening to these stations on either my 1985 GE Superadio II or my 1950 Zenith Transoceanic Radio, both radios of which have super sensitive and super selective tuners, I was once actually able to pick up WBAP out of the Dallas/Fort Worth, Texas area on my Zenith Transoceanic and my GE Superadio at night, and that station is over 1000 miles from where I live.

60Hz transformers like doorbells use rarely produce RF interference, I guess it's possible if they've failed, but usually when they fail you notice that they've stopped working within days of the interference.

That's what I figured, I figured the doorbell transformer was probablly not going to be an issue in this case.

I tell ya dues I wish I could find the interference in our house!!

Noise all over my radio,espeically in my room!! (I dont know whats causing it)

When we have a power outage turning on a battery powered radio is a treat!!! (Then when the power comes back so does the noise)


I hate the crap they make now,no shielding,just crap.........

A couple years ago when my dad got rid of the cable boxs alot of it went away so that was coming from the set top boxs...... Totally disgusting!!!

Walk around with a portable, this helps localize the source of "hash" that can appear at numerous locations on the bands.

If it's NOT your place, then investigate outside or the neighbor and fix their own issue in the process.

It may be a bad light bulb, always-arcing ballast/starter/photocontrol, etc. If its coming from a chinese crap wall-wart or similar junk, say it was a fire hazard and they usually thank you.

Somo "innocent" LED bulbs make a lot of RFI due to it's internal crappy SMPS.