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

[DavGoodlin]

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.

[zeno]

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
LFOD !

[vortalexfan]

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.

[dcl0]

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.

[zeno]

Originally Posted by dcl0

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

Zeno
LFOD !

[Doug]

Try Google

solar panel rf interference

[vortalexfan]

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.

[vortalexfan]

Originally Posted by zeno

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

Zeno
LFOD !

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.

[vortalexfan]

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.

[Electronic M]

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.

[vortalexfan]

Originally Posted by Electronic M

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.

[Dude111]

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!!!

[DavGoodlin]

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.

[Alex KL-1]

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