wrote in message
oups.com...
The funny thing is that i can happen at any time, somtimes it lasts for
the whole day, somtimes just couples hours or even minutes.

Yes, that is possible and likely. Here is what often happens: an
intermittent connection (usually one with some oxidation) is acting like a
rectifier. A rectifier is a detector (demodulator) for amplitude modulated
radio signals. Intermittent joints, splices, or connections can change with
the phase of the moon or the amount of lint in your dryer.