Earth Loop Hum

[robbieg]

Hi,

Running VoIP from my laptop with the power supply connected to the
mains introduces a 50Hz earth loop hum into the headset that is really
annoying for the other party. Unplugging the laptop from the mains and
running on batteries fixes this problem - but the batteries run down!
Also, muting the microphone also fixes the problem for the other party
- but they can't hear me speak.
Can anyone suggest a possible solution. I understand about removing the
earth wire from the plug but the power supply is already connected via a
2-wire Euro cable and the 3pin plug in the wall has a plastic earth
pin.

Thanks in advance.
Robbieg

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robbieg