Hearing radio through gas heater possible?

[janger]

Here's a bit of a weird one.

My grandmother (93 years old but "still with it" mostly) had a natural gas heater installed last year. It's one of those wall mounted heaters with a flue. Anyway, several weeks ago she told my parents she could hear the radio through it at night. I was quick to say it's not possible - either she's just hearing things, or maybe there was sound from some far-away sporting event or something being funneled down the flue. But she insists it is still happening and she sometimes hears music, sometimes the news, just like AM radio.

I haven't had a chance to witness this myself yet. But do any of you think this is possible - to actually pick up a radio station through the heater? I've done a bit of searching and haven't found much related to this. A couple of things I've thought of though is the flue acting as an antenna and some dissimilar metals in contact acting as a diode. Or maybe the control electronics are acting as a crude radio receiver. But what would be the speaker? Maybe the flame could act like a plasma speaker?

 

[JaredJames]

Unlikely at best.

It sounds to me like the exhaust is acting as a microphone and picking up nearby sounds and it is then funnelling them into her house where she can here it. Think of it like a crude stethoscope.

 

[Borek]

Have you read https://www.amazon.com/dp/0684853949/?tag=pfamazon01-20? Sacks describes similar case. I am not suggesting medical condition is the problem here, but... who knows.

 

[janger]

Yeah I'm thinking towards the flue funneling noises down. The problem with a "medical condition" is other people have apparently heard it. I'll know more when I hear it myself. Was just wondering if any of you thought it was plausible at all.

 

[AlephZero]

You didn't tell us anything about where she lives. Is it a house on its own, or an apartment in a block? It could be the sound is being transitted from another apartment through the structure of the building into the flue, and then into her room.

It is possible (but unlikely, with modern design and construction methods) that the electroncs is acting as a crude radio receiver, but I can't visualize anyting that would act as a loudspeaker to turn the electrical signals into sound. Back in the 1960s, there were sometimes problems with things like electronic organs acting as radio recievers and picking up calls from taxis passing the building etc, but obviously electonic musical instruments do have speaker systems.

 

[cosmik debris]

This is a real phenomenon. I have heard radio through my computer modem and through a toaster. It usually occurs if you live fairly close to a radio station's aerial. Some AM stations put out a lot of power. Others have reported sound coming out of fillings in their teeth.

 

[JaredJames]

This is a real phenomenon. I have heard radio through my computer modem and through a toaster. It usually occurs if you live fairly close to a radio station's aerial. Some AM stations put out a lot of power. Others have reported sound coming out of fillings in their teeth.

Any support for these claims? (particularly the teeth one)

 

[russ_watters]

This is a real phenomenon. I have heard radio through my computer modem and through a toaster. It usually occurs if you live fairly close to a radio station's aerial. Some AM stations put out a lot of power. Others have reported sound coming out of fillings in their teeth.

I dealt with this problem at a building next-door to another building that had a radio broadcasting antenna in its spire. On one particular floor, there was a constant ambient humming (the lights, maybe) and all computer speakers, phones, etc. played the radio station(s) they were broadcasting next door. You could also hear it by touching an electronic stethoscope to the window mullions.

For fillings, it may well be an urban myth, but in other circumstances, it is verifiable. Googling for "radio interference speakers" turns up tons of hits:

I recently bought new Dell 5.1 Surround Sound speakers and I notice that I
am picking up a local radion station whenever I turn the speakers on even
when the computer is off.

What shall be done?

http://www.velocityreviews.com/foru...rs-picking-up-radio-station-interference.html

 

[Drakkith]

There's a big difference between interference in a speaker wire causing the speaker to emit sound and a heater, which isn't designed to. I didn't think that absorbed EM radiation could induce vibrations in objects, but only caused a small amount of current to flow. I can't see any connection based on my own limited knowledge, but I cannot rule the possibility out either.

 

[janger]

I was going to post a link to the "radio through speakers". But most of those problems occur in devices with a speaker. Poor grounding/shielding allows the wiring to act as an antenna, IIRC.

I also searched about picking radio up through teeth fillings and haven't found any verified cases. Didn't Lucille Ball claim to get this? And Mythbusters debunked it I think.

She lives in a single house. There are no ham radios or radio transmitters near her that we know of. However I just remembered this heater doesn't have a chimney. It's a newer one with a side vent out the wall, less than a metre from the ground. So that stuffs the chimney idea.

But I just read something very interesting from http://en.wikipedia.org/wiki/Furnace :

The ignition system must prove that a flame is present to continue the gas flow, or if there's no flame, then shut off the gas flow through the gas valve to prevent a possible explosion. It also must not be fooled into thinking there is a flame present by a flame sensor that is touching the ground from being broken or bent. The way it does this is by a diode effect where the sensor surface area is less than 10% of the ground surface area. This produces a half-wave of electrical current from each full wave. The ignition control circuit detects the half-wave to determine if the sensor is merely touching ground. If the ignition control receives this half wave signal from the flame sensor then combustion will continue.

Hmmm, so we have a diode, and an antenna from the remote thermostat wiring. How the actual sound would be created I don't know. I'm still skeptical, but it's not sounding as far fetched as I first thought.

 

[Drakkith]

The problem is that the electrical signal has to be converted into vibrations in the air. I don't know of any way an unamplified signal can do this without a speaker of some sort.

 

[janger]

The problem is that the electrical signal has to be converted into vibrations in the air. I don't know of any way an unamplified signal can do this without a speaker of some sort.

Like this? :
http://www.swtpc.com/mholley/PopularElectronics/May1968/Flame_Amplification.htm

Plasma speakers (which flame speakers are a "subset" of) require some decent pre-amplified current to work I think. But I'm interested to know how much current flows through the flame sensor in a typical gas heater. Some crystal radios never used amplifiers - signal was fed straight to an earpiece. Maybe the heater cabinet could act as a soundbox to increase the volume?

This is all assumption though. I've been telling granny and my parents it's just not possible. My uncle who's a know-it-all said the crystal oscillator in the control circuitry is acting as a receiver. I don't buy it. Then again with the control solenoids (inductors) maybe they could form a resonant circuit? There's still a missing sound generator in his idea though.

 

[Drakkith]

Now that is interesting!

 

[janger]

Now that is interesting!

Sure is. Great high frequency response (>100kHz). Check out some of the plasma speakers on youtube.
http://www.youtube.com/watch?v=DTYuIHVgGYU&feature=related

AFAIK the only real difference between plasma speakers and flame speakers is the way the ionization occurs.

 

[JaredJames]

She lives in a single house. There are no ham radios or radio transmitters near her that we know of. However I just remembered this heater doesn't have a chimney. It's a newer one with a side vent out the wall, less than a metre from the ground. So that stuffs the chimney idea.

Actually, it boosts the idea of it funnelling sounds into the house.

A chimney wouldn't be as good as it would vent through the roof and be aimed in the wrong direction.

The fact it is just above the ground at an average "device producing sound" height makes it more likely.

How close is the house to another property? How close is the chimney to another device producing sound in the house (next room etc)?

 

[AlephZero]

On one particular floor, there was a constant ambient humming

That could be a standing wave resonance caused by the size of the air spaces.

I had a similar effect in my house. In the hallway there was an electrical transformer to power the doorbell, mounted in a small box on the wall. There is no audible hum in the hallway, even if you put your ear next to the box.

However in the room on the other side of the wall, there is a hum at mains frequency, and you could easily map out the standing wave pattern by changing your position in the room.

The wall was a a solid load-bearing structure, not a partition on a frame.

There was no doubt about the source of the sound in this case, because the bell transformer had an on/off switch The fix was to move it onto a different wall.

 

[DaveC426913]

Any support for these claims? (particularly the teeth one)

Of course!

http://www.google.ca/search?q=laurie+partridge+radio+fillings"!

It's on TV, it has to be true!

 

[janger]

A chimney wouldn't be as good as it would vent through the roof and be aimed in the wrong direction.

The fact it is just above the ground at an average "device producing sound" height makes it more likely.

I don't agree. These vents on new heaters are small and the exhaust is forced out under pressure.

I was thinking the chimney since she lives near a river that has floating restaurants going up and down that often play music. The river already funnels sound along it. And a chimney on the roof would have a less obstructed "view" of this sound compared to ground level due to the high river banks and trees lining them.

I wonder though, I think these heaters also suck air in through a side vent. Maybe this acts as a more efficient "stethoscope".

Also my parents told me last night they haven't heard the sounds. So maybe this is just a case of auditory pareidolia. Granny lives by herself and we all know the tricks loneliness can play on us. But for her age she is by no means losing her mind.