Very severe interference on the AM band. - Videokarma.org TV - Video

dieseljeep · #1 09-02-2019, 12:09 PM

I do most of my old radio repair and restoration in my building that is in a complex of storage and workshop buildings. The only utilities available are natural gas and single phase electric, no water or sewer, so it really can't be considered as an industrial complex.
The interference is totally unreal! Most of it is from the line, a nasty buzz.
I'm blaming the remote reading electric meters. I was trying to trace the noise from the area with my Optima high performance portable radio, similar to a GE Superadio. You put the radio next to the electric meter and it emits all kinds all kinds of strange noises.
I'm calling the electric supplier.

Electronic M · #2 09-02-2019, 02:30 PM

We've got a remote reading meter here too and it doesn't seem to put out noticable noise...

dieseljeep · #3 09-02-2019, 07:19 PM

Quote:

Originally Posted by Electronic M

We've got a remote reading meter here too and it doesn't seem to put out noticable noise...

My residence meter doesn't create any interference like the one in my shop.
The main reason I'm inquiring is because I read on another website that someone else was experiencing the same problem.
I'll end up doing some more research on the issue.

Sandy G · #4 09-02-2019, 07:59 PM

Don't really know it, can't prove it, but I have a STRONG sneaking suspicion that our local utility does a REMARKABLY Piss Poor Job on interference... You drive down a street, anywhere in town,, & almost every transformer you pass the AM radio sounds like it needs new caps...Unhhhhh.. doesn't rise & fall, just a harsh "Bad Cap" noise we're ALL too familiar with.. When one of the gummint offices, banks whatever sends out a data stream, THAT has a similar sound. But WHY do you wanna lissen to Junky, Clunky Ol' AM anyway, right ?!? Grrrrrrrrr...Gawd, I LOVE Moderne Life...

maxhifi · #5 09-02-2019, 08:16 PM

I went through this a while back.. traced it mostly to LED and CFL energy saver light bulbs. A computer monitor power supply was bad news too.

dieseljeep · #6 09-03-2019, 10:07 AM

Quote:

Originally Posted by maxhifi

I went through this a while back.. traced it mostly to LED and CFL energy saver light bulbs. A computer monitor power supply was bad news too.

I shut off all breakers in the building but one. The only item connected to the one circuit is the radio under test. The very same noise!
I fully understand that switching power supplies, LED and CFL lamps cause line noise.

Kevin Kuehn · #7 09-03-2019, 11:02 AM

Rf interference can ride just fine on any long earth grounded wire, so shutting off breakers doesn't really isolate it much.. Tried taking the radio outside and plugged into a long extension cord, as far from the buildings as possible? If your buildings are metal siding it's almost like being inside a Faraday cage with all the interference being emitted from internal wiring along with the radio signals. What you really need is a long outdoor antenna(as far from building wiring as possible) with a shielded lead in.

jr_tech · #8 09-03-2019, 02:54 PM

If the interference is entering the radio through the power cord, a battery operated radio might be somewhat immune to the problem, and imho, a better choice for “sniffing” out the source.

jr

Tripredacus · #9 09-30-2019, 03:07 PM

Quote:

Originally Posted by Kevin Kuehn

If your buildings are metal siding it's almost like being inside a Faraday cage with all the interference being emitted from internal wiring along with the radio signals. What you really need is a long outdoor antenna(as far from building wiring as possible) with a shielded lead in.

I have/had a working solution for buildings like that, however I never did try to figure out how it worked. Being in buildings that were dead zones for AM/FM (or even cell service) I had used strong magnets to connect radio antennas to metal parts of the building, or next to the steel support beams in the walls. The type of magnets used were just ones from old/busted speakers.

Prior to the digital switchover for OTA television, I had used hard drive magnets on analog TV tuner antennas. This does not work for digital OTA that I can tell.

vortalexfan · #10 10-01-2019, 01:00 AM

OK So here's an interesting thing I found out the other day when I was at my parents place, apparently surge protestors can also act as AC Line Noise Supression Devices.

Here's why I think this, as I had mentioned before when I would plug any sort of radio straight into a power outlet in my parents house and the overhead florescent lights in my parent's basement are on, I get a loud buzzing noise on the FM Band and absolutely no reception on the FM Band (except for one super strong 50kW FM Station that is just a couple of miles up the road from my parent's house and even that station is kind of noisy.)

But then when my dad took this old boombox I had left at their place for me to listen to when I spend the night at their place on early Sunday Mornings when I get off of work at 2:30 AM, and brought it to the basement and plugged it into the surge protector that their TV in the basement was also plugged into, the radio made absolutely no noise whatsoever when the lights in the basement were on. Go figure...

So it seems that maybe the answer to our noisy radios in our homes is to use a surge protector.

maxhifi · #11 09-03-2019, 02:57 PM

Quote:

Originally Posted by dieseljeep

I shut off all breakers in the building but one. The only item connected to the one circuit is the radio under test. The very same noise!
I fully understand that switching power supplies, LED and CFL lamps cause line noise.

Battery radio has same problem? Can be interference from neighbor too.

vortalexfan · #12 09-05-2019, 01:47 PM

I don't have any issues with the AM Band in this regard but I do have issues like this on the FM Band ALL THE TIME! Whenever I go by any sort of business like a gas station or even where I work at a higher end Amish Inspired Restaurant in a town that is mostly dead when it comes to cell phone signals the FM band gets a loud buzzing noise on it that completely wipes out the station until you drive away from those locations, even traffic signals have been known to cause tons of interference on the FM band in my car. And where I work (speaking of which) I've tried to use a walkman radio on the FM Band and it is completely dead signal wise, it won't pick up anything just a loud humming/buzzing noise.

In the home setting my parents have overhead electronically ballasted florescent lights (T9 Style Florescent Tubes) and whenever those lights are turned on the FM Band on any tabletop radio or stereo receiver just hums really loud and doesn't pick up any stations.

weird thing is that at my house I have no issues with the FM band (but I don't have any modern electronically ballasted florescent lights in my home either or any "dirty" switching power supplies).

Chip Chester · #13 09-02-2019, 08:20 PM

If you do find it's the meter, invite the FCC to the party.

decojoe67 · #14 09-03-2019, 06:12 AM

It's funny, but when I use my transmitter I get a buzz. If I ground the transmitter and, get this, turn on my hall light, the buzz is all but gone! I would suggest turning different lamps on and off.

Electronic M · #15 09-03-2019, 09:03 AM

The worst interference source in my house is the commercial grade fluorescent fixtures in the garage... only 1-2 am stations can make it through that wide band buzz storm. I'm glad it isn't run when I typically listen to AM, but I have to remember to only variac radios that are 'decontaminating' in the garage during the day so I can get meaningful reception.