Very severe interference on the AM band.
 

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. :thumbsdn:

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. :scratch2:

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...

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.

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

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.

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.

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. :scratch2:

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.

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

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

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).

I have a minor problem with FM at my house. There are carriers every 31 kHz across the FM band, worst between 96 and 104 MHz. They appear at some other frequency
ranges from 27MHz to 300 MHz, and not at all at some other places.
They drift about at harmonics of 31+-0.5 kHz.

Luckily its FM and they are weak enough to be audible only if within 3 kHz of the main carrier or 38kHz, as they are 30 dB below the 19 kHz signal. They are not from
my apartment.

I want to travel way out west in the boonies to evade QRM. I'm getting tired of AM and HF buzz! My loop rejects most interference but trying for GOOD DX is a real pain! What ever happened to Uncle Charlie?

Who's Uncle Charlie? And I have no problems DX'ing on the AM Band on any of my radios and I live just outside of town where I live, and All I'm using are early 1930s and and early 1940s vintage wooden tabletop radios that required a 30'+ length of wire and a good ground to receive stations! :yes: :thmbsp: :music:

You just need to move to Northern Indiana and you'll have great DX'ing because you're right in the middle of the country where you can pick up stations from about a 750+ mile radius from here.
I can pick up stations as far east as New York City and as far west as St. Louis and as far South as Nashville, and as far North as Toronto, Canada, all on the AM band between 7PM and 6AM, and these were just stations I was picking up on my Westinghouse WR-10 Tombstone radio.

I can't imagine what my 1942 FADA Model 176 could do with its more advanced AVC and Better IF and RF stages!

Uncle Charlie was shorthand for the Federal Communications Commission. Back in the 70s, during the CB craze, ALL of us had a "Weather Eye" out for him, 'cause so many were running illegal "Linears" to boost the power, had extra crystals, illegal antennas, all that stuff.

I use middle 30's, early 40's and late 50's radios. I use loops for antennas: hard to install a straight wire outside.

I live in northeastern Ohio, near Cleveland (30 miles from town, within a half mile of the south shore of Lake Erie), and at night can hear many stations on most of my AM radios from within the 750-mile radius you mention. The FCC has done away with "clear channels" on the AM broadcast band; these were frequencies on which, after local sunset, there was only one 50kW station in operation all night long; during the day, other local stations were on these frequencies as well, but they were required to sign off at local sunset time. After the local stations left the air for the day, the "clear channel" stations could be heard almost nationwide after sundown.

The abolition of the clear channels ended that, but the FCC has a new system in place now where these former clear channel stations can be heard within a 750-mile radius after dark. The clear channels were done away with so that former daytime-only AM stations could operate 24 hours, with directional nighttime antenna patterns and lower nighttime power. There are a few "daytime-only" stations left; one of them is a 1kW ESPN sports radio operation in Cleveland on 1540 kHz. Many "daytimers", however, have taken advantage of the new regulations and are now operating 24 hours a day, again with directional antenna patterns and lower power after sunset.

I just run my straight wire inside the house and no problems.

I've picked up your Cleveland ESPN Station on my old Westinghouse Tombstone radio at night, I've also picked up WGN From Chicago on my radio as well and I think I can pick up WOWO AM 1190 out of Fort Wayne on my radio as well (WOWO was one of those Clear Channel stations you spoke of and they still do operate at 50kW both day and night).

I have also picked up a Station from Toronto Canada that is an Oldies station that plays music from the 1940s-1980s.

Probably coming from people who have SMART METERS .... They are aweful........ I love AM radio and whenever I drive by certain houses,I get nothing but noise all over the dial!!

These meters put out dirty electric and they are not good healthwise either.....

http://safeliving.tamers.biz/index.p...ty-electricity

http://web.archive.org/web/201309211...rm-your-health

http://emfsafetynetwork.org/maine-ut...e-interference

Thanks for a 45 -year flashback Sandy!:thmbsp: These days "Charlie" is raking in the dough from the spectrum repacks. I don't think Charlie follows up on obscenity violations anymore, like in the 80's

We of a certain age played with our walkie talkies during the CB craze. Radio Shack made a kids base station that received all 23 CB channels but transmitted only 200 mW and just channel 14.

I noticed the label on these "rigs" said it complied with FCC part 15. My brother and I were determined to find that nanny-state-mandated part 15:D, modify or remove it and transmit some real power.

I found a 20-foot well pipe and stood it on end at our fort up in the woods, with a big ground clamp to connect a wire the "talkie's" antenna. At least I knew a 3-foot whip antenna was lame at 27Mhz, but ignored the importance of a ground plane.

AM interference is best located with a portable. My personal experiences are: poorly grounded fluorescents, LED bulbs but only when physically close, failing photocells on old mercury vapor outdoor lights.

I always put an X2 safety cap across line in AC/DC radios and a Y2 from line to ground in transformer supply sets but I'm not sure that helps much.

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.

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.

You established that the interference was conducted interference. In general, interference can be either conducted or transmitted or both.

You could probably put a line filter in series with the fluorescent fixtures and kill all the conducted noise in the house.

So something like the picture below?

Yup. Make sure it is rated to handle the current draw of the lights and anything else that might be connected to it.

It was always claimed back in the "CB" daze that "Unca Charlie" had special cars w/fiberglass tops to go out & search for those bastard CB Scofflaw types who were runnin' "Leenyars", extra channels & all that. I kinda thought that was likely hogwash, until I remembered this WAS the Fedederal Gummint we were talkin' about, the same bunch who spent $300 for Hammers, & $900 for Crapper seats... The FCC claimed CBers were interferin' w/ Aircraft Communications, SOMEBODY could get Seriously Killed..That was their song on EVERYTHING..

Your reminding me of an old radio Blooper off an LP compilation there of, where in an announcer giving the details of an accident reported that "seven people were killed...Three of them seriously". :D

I think I cribbed it off an Eddie Murphy riff... THAT dude, even tho he was Filthy,even WAY more than I am, could make me Pee me Pants.. Mighta been the "I plays Footbawl on th' Footbawl field, Wid a Footbawl..My Bidee was runnin' Aroun', Tacklin' Shit..."

where would one get one of those line filter devices?

If you found that pic you posted you would know better. Google may be helpful...

As for current rating you need to figure out how much your lights draw(the ballasts should have a rating label), and if anything else could be connected to the circuit (for instance if the lights are wired directly into the ceiling junction boxes are there any outlets on the circuit).

I've got a couple of used line filters I've picked up at garage sales and the like to reduce noise from my power inverters for use at radio swapmeets , but I've never needed one bad enough to buy new.

Well that was just a google image search that I found that picture through (it was actually sourced from wikipedia's article discussing what line filters were and how they worked.)

The reason why I was asking was because I was wanting to see if there was any non-online sources for those line filter devices as I would prefer to buy them locally if possible rather than buying them online and having to pay shipping costs (which can be almost twice as much as the part itself costs).

That'd have to be one dirty signal to make it all the way from 27 MHZ to 118/137 MHZ ... Course , what some heaters did to TV reception was just about criminal :D

(For anyone who don't know , a "heater" was CB slang for an illegal linear amplifier , most of which being quite UN linear in their RF output)

Well since the air band is used on the AM mode,CB could easily interfere....... (Especially with a dirty amp)

Fixed it

I get the same nasty sounding interference from solid state dimmer switches. I used to have a dimmer on the front porch light. If the light was on, AM radios anywhere in the house would make a horrible loud buzz.. even on battery operated radios.

One day, just to see how far it would pick it up, I turned on that switch and walked outside. I was about 150 feet from my house before the buzz went away. After that I replaced that switch with a regular non-dimming switch.

When I lived in my previous home, the old lady across the street had one of those bright halogen pole lamps with a dimmer next to her chair (the kind that was setting people's drapes on fire several years ago), and anytime she had that light on, the radios in my house would pick it up.

Currently, there's a light in my shower that operates on a dimmer. If that light is on, AM radios make that loud buzz. You can hear a change in the buzz as you brighten and dim the light.

So if you have anything with a dimmer, play with it and see if your buzz goes away.

I have a 2006 flatscreen plasma wreaking havoc on my AM and SW bands.. I remember the dimmers as a kid. It was fun turning them up and down, sounded like a fly on the radio.. :D

SR