When listening to the radio somewhere with very poor reception, sometimes moving about, even lifting a hand or something, can make all the difference between hearing static and a clear signal.
What’s going on with the signal in those situation? Does my body act as an antenna absorbing the weak signal or does me moving about actually improve on the radios reception?
Shouldn’t most radio waves travel through my body with very little absorption?
if you are near the radio your body can have an effect of making the antenna in the radio work better.
depending on the frequency of the radio signal and your body position you could reflect some signal if farther away.
Thanks
I get why touching the antenna helps the signal, but how does me being near the radio (but electrically isolated from it) increase the current in the antenna?
I’m guessing the radio waves creates an electrical current in my body which in turn may affect the antenna through electric fields, but that seems like getting an amplified signal for free?
Does refraction/reflection has anything to do with it?
your body has electrical capacitance which when close to but not touching the antenna can make the antenna work better.
I did some more research and i think i understand the phenomenon now. I’ll just include the explanation i found in case others are interested.
Apparently, the reception change is due to an effect known as scattering. Scattering happens when radio waves induce a current in objects (antennas, human bodies etc.) which in turn generate a field(waves) of their own.
Now depending on the distance from the scattering object to the radio receiver, the new waves may be out of phase with the original signal. The result is that the combined signal reaching the receiver is subject to either constructive(in phase) or destructive(out of phase) interference.
The position of humans(and other objects) adds to the combined signal through scattering and thereby affects the signal reaching the receiver to be better/worse.
I hope i got that right.