Question: I received a radio wave with my homemade antenna that it sounds like a motorbike, like a Harley Davidson. Which type of signal it could be? it could be about the sun or the earth magnetosphere? It’s for a school presentation. Thanks. – Gerard
Answer: The source of a radio signal depends upon the frequency that you were tuned to (among other things), but I suspect that if you were using a standard radio frequency (a few 10s of mega-Hertz) that what you received was a man-made transmission of some kind. There are a number of places on the web which can help you identify man-made radio broadcast noises. For example, W2SJW’s collection of strange radio noises contains numerous samples of man-made radio noises. You might try listening to some of these sound samples to see if they sound like what you are hearing.
If you think that these might be sounds produced by ionospheric effects, you might try the Earth Sounds web site (although this web site appears to have fallen into disrepair…). There are only three sound samples listed, and none of them sounded like a “motorbike”.