Yes exactly I was talking about the background crackle!
I solved!!!
By chance I discovered that the problem was an external HD connected to the pc!
They are the HDs that have no switch on and off, but come on when you turn on the PC and if you don't use it they go into stanby
If I disconnect the power to the HD the background crackling disappears!
HD works perfectly, or has problems or it is the 12V 1,5A power supply that, under strain, sends some spurious out.
It is known that the BITX40 is sensitive to anything that happens on the power line. Turn on a light and hear the crackle in the BITX, turn on the air conditioner and hear the crackle ... I'd like to find some system to be able to eliminate this sensitivity.
Thank you all
Sergio
