Hello all !

I just want to tell you my old mistery, and you will see why I'm going to tell you this.

So years ago, I was allways listening to my radio. It was a radio mo-dem, and it was very veak so I generally didnt got signals in them. I detected a noise can be heard above the general noise, perhaps you know where its come from.

So when you turn on your radio, or your fm radio and swich it to where no radio stations signals here, you will get the sound like : ssssssssssssssssssssssss . And in this sound, cant remember correctly, there is a pulse, or interference, cant really explain what it is, but its clearly different and detectable. Its repeating every 21 or 11 minutes, I dont remember correctly. Its also been detectable from the car radio, and some older television. First I tought that its some transformator background noise from our electrical systems, because its all the frequencies and you can hear it everywhere. But I was on an empty field and still heard this voice so maybe it isnt coming from earth, perhaps its a pulse or an old neutron star perhaps, I never could research from what is this noise coming from. Seti working with radio telescopes so perhaps you can tell what is exactly is.

Without knowing more info about the type of signal you were hearing I can only offer this:
An intermittent "hash" or "popping" noise is probably coming from lightning strikes. Lightning will emit a very powerful pulse of energy which can be heard from long distances. You don't need to be close enough to see or hear the actual strike to be able to detect the pulse in a radio. This property is used in several inexpensive or homebrew "thunderstorm warning systems". In one homebrew system I've seen, a cheap AM radio is used as the detector with the speaker removed and the audio output sent to a pulse detection circuit which ignores the background static but will sound an alarm when it detects the higher powered pulse from lightning strikes.

If you could provide a clearer description of the signal you hear someone may have a more accurate answer.

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Jim

Some people plan their life out and look back at the wealth they've had.
Others live life day by day and look back at the wealth of experiences and enjoyment they've had.

I think that Jim-R has it right.Lightning strikes somewhere on the earth 100 times a day on average (or so I'm told) that's about every 15 Minutes.

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Old enough to know better(but)still young enough not to care

I'll try to catch the signal again and try to record it. I'm pretty sure its not lightning because its cyclic, I also try to re-estimate the cycle time. I'll let you hear when I'm finished.

I think that Jim-R has it right.Lightning strikes somewhere on the earth 100 times a day on average (or so I'm told) that's about every 15 Minutes.

I would be inclined to think that it's actually 100 times a second on average (for the entire earth). There's no way it could be one lighting strike every 15 minutes......

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I think that Jim-R has it right.Lightning strikes somewhere on the earth 100 times a day on average (or so I'm told) that's about every 15 Minutes.

I would be inclined to think that it's actually 100 times a second on average (for the entire earth). There's no way it could be one lighting strike every 15 minutes......

An old estimate of the frequency of lightning on Earth was 100 times a second. Now that there are satellites that can detect lightning, including in places where there is nobody to observe it, it is known to occur on average 44 ± 5 times a second, for a total of nearly 1.4 billion flashes per year.[90][91] 80% of these flashes are in-cloud and 20% are cloud-to-ground.

Source: Wikipedia (lightning)

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If anybody is familiar with instruments like the Storm Scope or the Insight clone of it, that are intended to catch lightning RF effects, you know that the RF effects of lightning on electrical equipment are limited in range by the sensitivity of the equipment. So a few minutes between pulses could be the effect of relatively local lightning.

Also, could this be a beat frequency, between two not-quite-aligned oscillators somewhere in the circuitry?

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