Naked Science Forum
Non Life Sciences => Technology => Topic started by: Karsten on 06/01/2009 23:54:17
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This has most likely been discussed already, but I was not here then.
How is it that sometimes when I adjust my radio or TV signal my physical presence changes the volume or I have to occasionally keep the hand near the radio to even get the station? The moment I move my hand the station goes away. At other times, I adjust and walk away and the signal does leaves as well.
Full of wonderment,
Karsten
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Since I do not know how to change the subject line and it is apparently preferred to be in question form, whoever changes it, here is the QUESTION in question form:
"How does my body influence electromagnetic waves?"
I will do it right in the future.
Karsten
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I do not know how to change the subject line
Log in then click on the modify icon which will appear of the right hand side of your post
[ Invalid Attachment ]
You can then modify your post including the subject headline.
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Radio waves can be absorbed, reflected and refracted (bent) by the human body, (effects are dependent on the wavelength).
The human body can also act as an antenna, i.e. when you remove your hand it is analogous to unplugging the aerial.
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You are mostly water with dissolved salts, which makes you a pretty good conductor. Your body acts just like one of the 'parasitic' elements on a normal TV antenna. (Only one of the elements on most antennae is actually 'fed') The parasitic elements have currents induced in them which modify the directivity of the antenna. You have the same effect.
It is worth saying that, wherever you are and whatever you are doing, all the radio waves which are going past / through you are inducing small currents in your body.
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I had that feeling that it would be my body's composition. Is there any way to avoid this? I mean, what do I do to adjust the radio/TV without having to deal with this problem? Long rubber stick? Rubber gloves?
Karsten
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The only way to stop those currents flowing through would be to slice your body at regular intervals and slide an insulating plate between the slices. That could affect more than the induced rf currents tho', so you may not want to try it.
If you really want to stop your body affecting the signal received by the TV you need to get an antenna up on the roof. That will provide a better signal strength and remove your body from doing harm at the antenna.
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Well, ehmmmm, thanks for the suggestions. Regular intervals. Slicing. Inserting insulating plates. Hmmm. It is a great idea and I am sure it works, but I may pass on that one. Thanks though. Hehehe (nervous laughter)...
Karsten
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Like a sliced loaf?
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Is there any way to avoid this?
I mean, what do I do to adjust the radio/TV without having to deal with this problem? Long rubber stick? Rubber gloves?
Karsten
An better antenna for your radio or TV would avoid this problem; ideally an outdoor one in line-of-sight of the transmitter.