Garage door spring picking up AM radio signal!

[Hypnotoad]

My in-laws live right next to an AM radio antenna and they asked me if I could track down and fix a random radio signal they were picking up in the house since I'm an electrician. I don't know what I could do about it, since I was over there anyway I thought I'd check it out. They said that they were pretty sure the signal was being picked up by the copper pipes in their basement. I thought the whole thing sounded just crazy, and I'm sure I even gave them a few looks like they were crazy. I've heard of people picking up radio signals on things like speakers, guitar amps and telephones, but never from pipes! So, I wasn't surprised when I didn't hear anything in their basement. They said the sound comes and goes.

That's when my mother in-law says follow me. I follow her to the garage and she says stand right here. Sure as shit, I could hear the local AM radio station next door coming from the garage door helper spring. She goes on to explain that they've heard it for years out in the garage and they've learned to live with it, but they recently started picking up the signal inside the house. They were getting real annoyed with the sound inside the house and wanted something done about it. The first thing I asked was if anything had recently been added, repaired or changed and nothing has, except their dishwasher quit working around the same time. I wonder if the radio station changed something on their end that made this start happening?

Has anyone ever heard of this happening? Is there anything that can be done? I tried Googling but didn't come with any solutions. There are plenty of people out there that pick up radio signals in their random electronics, but nothing this bizarre. I never did hear the sound inside the house, but the garage door spring definitely made a believer out of me.

 

[blazinlow89]

While I cannot offer a solution at the time, I will ask my grandfather who has dealt with high powered radio a TV signals for over 40 years. I vaguely remember him talking about having a similar issue when he lived in PA.

On a second note in my mothers house we used a converter for our PS2, TV had one thing hooked up to it and that was the PS2, had no connections to anything in the house other than the power plug. Well 3 rooms over we could pic up the signal (fuzzy at best) of the PS2 on the living room TV. Weirdest thing, never worked on any other TV, not connected to the COAX in the rest of the house.

 

[Hypnotoad]

That would be awesome. I don't see what could be done about it at this point.

 

[blazinlow89]

The only solution I can think of ATM would some sort of shielding, of course this would mean copper. However just shielding the spring would not be enough. You would probably have to do the entire garage in a mesh, or some sort of dry powder mixed in with paint. So many random metallic object in a garage to conduct signal. I would not think pipes to do it, but another thing would be the romex wires in the walls. I have seen the newer radio systems that transmit the signal through the copper wiring in your walls and the speaker utilizes it through a 2 prong plug. Being within such proximity to the radio station does not help either I am sure.

 

[The_Roadie]

Engineering-wise, any conductor that's pointing at the antenna is a suspect. Especially a coil like the spring. A pipe or conductor that's at right angles, and each end is about the same distance from the antenna, isn't going to be as affected by the field.

Is the garage door spring pointed generally AT the AM antenna?

Shielding for a low frequency like that may be too large to be practical, but a shorting wire might. Bond a 10-12 AWG wire (stranded to be flexible) to each end of the spring with something like a steel cable saddle clamp. See if that shorts out enough of the AM signal to suppress the noise. Otherwise just stuff rags into the middle of the coil to damp out the acoustic waves.

Grounding the house copper plumbing at multiple points should solve the pipe issue.

Also call the station if they haven't already. They're required to have an engineer on staff, and IIRC they're also required to mitigate interference like you're described. You may get some free grounding material and/or installation.

To see a serious RF voltage gradient in action, take a digital meter on an AC scale - the most sensitive if it's not autoranging. Hold the leads far apart with your hands in midair. Turn so the leads are equidistant from the antenna and see what the meter reads. Then turn so one hand is closer to the antenna and see if the reading changes. You might see 1-10 VAC field strength. Not much energy, but a sensitive meter can pick it up.

 

[Hypnotoad]

I did notice that the water heater and water softener in their basement haven't been bonded. I don't know if bonding them will help anything, but it should be done anyway.

The spring is pointed at the radio station. I'll suggest the bonding jumper to them.

They have called the radio station, but they can never get a hold of anyone that can help them. They've left messages and no one ever calls them back.

 

[meerschm]

if the spring extends, it should have a safety steel cable inside, to catch it when it breaks.

 

[The_Roadie]

They've left messages and no one ever calls them back.

Leave ONE message with the FCC and the station will be instantly motivated to return their calls.

Interference - Defining the Source | FCC.gov

But a bit of reading shows they may not be. The interference the FCC web site mentions is electrical only. A garage spring that acts as a speaker may not be covered by the regulations. Odd. Very odd.

The safety wire (if it's the kind I think) may not be bonded to the spring enough to be a short circuit in the AM band. I would LOVE to be able to watch this happening. Make a Youtube video - the singing gagage door spring. Catch it when the radio station is broadcasting Silent Night and it will probably go viral this time of year. If they take this idea and make $100,000 off Youtube ad revenue I want 10%.

 

[willn513]

This is neat. Grab some beers and just hang out in the garage! Why would you want to get rid of this? Garage door with built in am radio!

 

[Hypnotoad]

This is neat. Grab some beers and just hang out in the garage! Why would you want to get rid of this? Garage door with built in am radio!

A digital radio sits about 10 feet away.

I'll try to make a video, but I don't think it's loud enough.

 

[STLtrailbSS]

working in communications I see this quite often with a Tone Amplifier I can pick up am from just about any conductor if interference is present. I agree with roadie grounding to drain signal is the only think I can think of. Pretty crazy that it is audible by ear.

 

[Hypnotoad]

[video=youtube;WAWDUMEt2SA]https://www.youtube.com/watch?v=WAWDUMEt2SA&feature=youtube_gdata_player[/video]

Turn up your speakers. I took this video with my phone, it's not the best quality, but it's there.

 

[willn513]

[video=youtube;WAWDUMEt2SA]https://www.youtube.com/watch?v=WAWDUMEt2SA&feature=youtube_gdata_player[/video]

Turn up your speakers. I took this video with my phone, it's not the best quality, but it's there.

I can hear it just fine! Again, I find this to be awesome.

 

[Bartonmd]

I know I'm an EE, but I've always wondered if that kind of power level of radio signals has any long term affect on your health. If you can hear it in the garage spring, is it strong enough outside of their house that you can hold one end of a florescent bulb and have it light up at all?

Mike

 

[The_Roadie]

Yes, and here's the countermeasure:
View attachment 25583

 

[gmcman]

Sitting here using my laptop on a couple occasions in the last few months, I have a phone conversation coming from the fan vents on the side. Something inside is picking it up.