Weird audio experience

Quite likely. Probably local, fairly strong. could be a bad connection in your audio setup detecting the radio waves, or an overload in an amplifier.

It can be annoying if not wanted, but otherwise harmless.

It could be an older cordless telephone, people don't realize they broadcast conversations. Newer ones use different frequencies and modulation, less likely to be picked up accidentally. Baby monitors can be a culprit as well.

Cheap audio gear, especially the RatShack stuff, can rectify and amplify strong radio signals. In our house, near a bunch of radio and TV transmitters, Shack amplified speakers and telephones both tend to pick up stuff. Radio stations are pretty obvious; a 60-Hz or high-pitch hum may be a TV station; a one-sided conversation is probably a ham radio operator; a 2-side conversation is likely AM walkie-talkies or wireless intercoms something similar.

The speakers I have here make a sorta loud buzz when the volume control is set to *minimum*; turn it up just a bit and it goes away (there is actually a good reason for this!). I bundled all the wires together with twist-ties and it mostly went away (ditto.)

The blue LED died too... the Shack sells some real junk!

John

Not to get you paranoid, but there are radio (and TV and electromagnetic) waves not only in your apartment, but pretty much everywhere these days. Your FM radio wouldn't work unless the signal from all those stations was already present in your apartment, nor would your cell phone. Don't get too worried, though, as most of these signals are extremely weak and have to be amplified inside the electronic equipment in order to be useful.

Hearing an AM radio station isn't unusual at all, as lots of things can act as simple AM decoders (see below). You were hearing something a little more unusual in that it was a 2-way conversation. Most cell phones are encrypted and wouldn't make audible conversation when picked up by a random unintended bit of wiring. I think wireless phones are FM and also not likely to be picked up this way. So as John Larkin suggests, perhaps it was an AM walkie-talkie or a wireless intercom in a nearby apartment.

Intercoms and baby monitors have a pretty decent range. We used to listen to our baby monitor in the basement of our neighbor's house next door.

Some years back I remember an article in the Washington Post about how people living in apartments near the WTOP-AM transmitter tower would get WTOP from their *walls*. It's a very powerful transmitter in a highly developed area, and apparently the metal stud construction of the apartment walls was a reasonably good broadband AM radio.

I lived several miles away at the time, and it was common to hear WTOP in the background of phone conversations or in poorly grounded audio equipment.

- Randy

If your cell phone works in your apartment, then there HAS TO BE radio waves roaming though, right? Try placing your cell phone near your monitor. Androcles.

| Viviane |

You are swimming in a sea of electromagnetic waves, recoiling off of objects in the room and interfering with each other. This includes 60 Hz waves from all your electrical wiring, radio waves, short waves, cell phone waves, television waves, infrared waves, even gamma rays.

The ability of a receiver to amplify one of those and make them audible to you simply has to do with whether it is "tuned" to amplify that particular narrow band of frequencies.

Feynman remarked about this in a wonderful TV interview. He said that electromagnetic radiation is like sitting in the corner of a swimming pool, with the splashing of children sending ripples everywhere and in all directions, bouncing off the walls of the pool and passing through each other and making general chaos in the water. And then it is quite remarkable to think that one could sit in the corner of the pool and be sensitive only to the rises and falls of the water as they lap up against you, and somehow make sense of that mess to be able to tell where the children are and what they are doing, for that is precisely what we do when we "see" the electromagnetic radiation in the visible light realm.

PD

Quite possible.

Thank you all for your knowledgeable explanations. I don't own a cell phone so it has nothing to do with what happened, but at least now I know that it wasn't just me being tired or something.

Thanks again.

Viviane

This story reminded me of an experience many years ago in Bellingham, Washington. As I sat playing guitar in my living room, someone started talking to me through the big stereo speakers sitting there, and commented about how well he could hear my guitar playing. I spoke back and we had a very intelligible conversation -- high audio quality with good volume. I don't think he told me what carried his end of the conversation. Later that day I walked into a store with hi-fis and stuff, and all the sound from the speakers died right at that moment. I didn't notice it because it happened just as I walked in from the street, but the clerk mentioned it. This happened in the seventies.

The headset cable picks up the radio waves and they travel back into the soundcard where they interact with the amplifier circuitry whic then produces the signals that go back up the leads and you hear them.

It probably was CB and probably quite close.

Bye. Jasen

Years and years ago, a neighbor insisted that they sometimes heard Radio Moscow on their phonograph (which had no included radio, let alone short-wave). I sort of nodded indulgently, but one evening the man came over and said "I can hear it now!", so I went over. With no record playing (just its amp running), indeed I heard fragments of an English-language broadcast followed by a Radio Moscow station announcement. THis in the northeast of the US.

Another time I was watching the 11:00 PM news on TV broadcast channel 2. The signal was for several minute overwhelmed by a St Louis, MO TV station long enough to get the location.

Radio propagation and inadvertent demodulation in electronics can sometimes be quite weird.

Dennis

On a sunny day (Fri, 28 Oct 2005 01:02:49 -0000) it happened "Dennis Ritchie" wrote in :

Even *normal* radio signals with *intended* demodulation can be quite weird sometimes. _________________________________________ Usenet Zone Free Binaries Usenet Server More than 140,000 groups Unlimited download