• Get involved.
    We want your input!
    Apply for Membership and join the conversations about everything related to broadcasting.

    After we receive your registration, a moderator will review it. After your registration is approved, you will be permitted to post.
    If you use a disposable or false email address, your registration will be rejected.

    After your membership is approved, please take a minute to tell us a little bit about yourself.
    https://www.radiodiscussions.com/forums/introduce-yourself.1088/

    Thanks in advance and have fun!
    RadioDiscussions Administrators

Hum in local AM BCB stations

Well....all of the noise was back (and more) last night.

Walking around with the RFI meter, it seems to radiate as nodes off many metal things...even door frames and carports (even parked CARS).
I think there are about four or five different noise profiles, including Plasma TV noise, neon and fluorescent noise, AM Hum, and others. Looks like the worst noise, after the Plasma, is coming from the mall across the street. I'm going to check them out this week, for whatever good it will do (usually, when the noise gets this bad, they catch fire and it stops for a while).

I have to wonder...Do other people who live in apartments and condos have this much interference to deal with? If so, the broadcast business is doomed, no matter what we do. Wonder what it does to the 700 MHz "Broad"-band.

(BTW: Comcast has cleaned up the temporary drop next door. I wonder what they did with the ferrite, and did they even realize what it was.)
 
You're right. It's multiple sources of crud. Now who can get the FCC to fine the manufacturers of this %#@#Y^ into compliance
with part 15 rules? And why did they drop the ball in 1970 when the first TRIAC lamp dimmers started it all?

How would we suggest to the FCC that they apply and enforce the laws they've written which apply to EVERYONE, and not just
pick on the radio industry? They HAVE the authority to do so, the laws are on the books!
 
We had a problem some years ago at a station on 1220, The Transmitter was about 4 miles from the studio and one day, all we got in the studio monitor was a bad hum with the audio in the background. Chased my tail for days.Wound up being a balast in the reception room. Canged it and problem went away. Maybe the windings were loose causing vibration on that freq.
 
A problem I ran in to a while back....

The restaurant next door had a faulty neon sign. After working with them for a while (AFTER the FCC sent them a letter, of course), they decided to leave the one part of it disconnected, saying it was all going to be replaced "soon".

Later, they decided that having the "Take Out" portion of the sign not illuminated (even though it was plainly visible), was costing them "hundreds of dollars a day" in business, so they ordered the sign company to turn it back on....even after the sign company supervisor reminded them of their promise to the FCC and the fact that they would be liable for a $10K per day fine. (The sign company offered to put line filters on the sign, for about $250.)
The restaurant owner replied with some obscenities about the FCC's anatomical components, and ordered it back on. Problem was, the restaurant was a major sponsor on many local stations, including my own.

Now what? Fortunately, they went out of business a year later, so I only had to do without TV for 12 months. Problem is, somebody is opening the place back up soon. I don't know if they plan to repair the sign, replace it, or fix it.
 
Went out last night with the little MFJ-852 Line Noise Meter, which operates at 135 MHz.

Even with the most minimal antenna (about 4" per dipole), the noise was reading over half scale, and intermittently swamping the amplifier, from 200 feet away.

Looks like the noise is mostly coming from a brand new tanning salon franchise. They were closed (Sunday evening), but their machines were all operating with some sort of decorative, colored-light mode thing...one or two bulbs in each one. There are about eight of these machines, which looked like commercial transmitters or medical equipment in a way. The doorways to the rooms all have placards bragging about how many bulbs and how many watts they have, for "Extreme Tanning".

The website for the tanning beds shows they draw over 11 kilowatts each. No wonder it looked like a transmitter facility! Now, if they'd quit broadcasting on 800 KHz to 12 MHz............

We've had problems for twenty years with the mall (mostly neons and fluorescents), but nothing like this.
 
kenglish said:
Went out last night with the little MFJ-852 Line Noise Meter, which operates at 135 MHz.

Even with the most minimal antenna (about 4" per dipole), the noise was reading over half scale, and intermittently swamping the amplifier, from 200 feet away.

Looks like the noise is mostly coming from a brand new tanning salon franchise. They were closed (Sunday evening), but their machines were all operating with some sort of decorative, colored-light mode thing...one or two bulbs in each one. There are about eight of these machines, which looked like commercial transmitters or medical equipment in a way. The doorways to the rooms all have placards bragging about how many bulbs and how many watts they have, for "Extreme Tanning".

The website for the tanning beds shows they draw over 11 kilowatts each. No wonder it looked like a transmitter facility! Now, if they'd quit broadcasting on 800 KHz to 12 MHz............

We've had problems for twenty years with the mall (mostly neons and fluorescents), but nothing like this.
Click to expand...

Join the campaign to outlaw those salons. They have been found to be a leading cause of skin cancer and from your description I can see that concept as sustainable. I used to like to tan (outside naturally) when I was younger and had a big back yard that was enclosed so I could avoid tan lines. But now there is a song that applies to me for sure: http://www.youtube.com/watch?v=rX28RySkENM
 
My plastic surgeon Aunt used to refer to those salons as 'melanoma incubators' when they fist came out. She made a fair piece of change clipping off the results some years later.
For the noise problem, can you get the local utility to put a hash filter on the main feed to the place?
 
I was lying awake last night, and noticed the audible hum in the bedroom wall again. It's been there for years.
I was wondering what could be causing it....loose wire in the outlet? Solenoid on the gas valve in the fireplace on the other side of the wall?
Ahhhh! A LittleLite gooseneck lamp on top of the rack in the living room. It has a wall-wart to give 12 VAC, and the light has a dimmer on it, but doesn't turn completely off, I guess. The wall-wart always seems slightly warm to the touch, so it must pull some power even with the bulb dark.
I'll have to see if it made any difference...at 12 midnight, there's enough noise from the mall to make it hard to tell.

I also tracked down some of the weird noises, like at 500 KHz ("Grung'gah, Grung'gah, Grung'gah") and at 770 and 1600 ("Deedle, Deedle, Deedle") to the Cable TV wiring in the ceiling/attic. It seems to localize at several spots, maybe where somebody put staples in to the coax when they built it. I can hear analog TV audio at those points along the ceiling and down the walls.

Darn RG-59/U and Digital Cable!!! :mad:
 
Status
This thread has been closed due to inactivity. You can create a new thread to discuss this topic.


Back
Top Bottom