"Charles"


Switch-mode power supplies are dirty ... lots of harmonic energy. The
interference is both radiated and sent back into the ac mains.


** But they don't usually generate energy in the FM broadcast band ( i.e.
88 - 108 MHz) - that is more likely to be due to the CPU and associated
high speed circuits inside the PC.




....... Phil

"Phil Allison" wrote in message
...

"Charles"


Switch-mode power supplies are dirty ... lots of harmonic energy. The
interference is both radiated and sent back into the ac mains.


** But they don't usually generate energy in the FM broadcast band ( i.e.
88 - 108 MHz) - that is more likely to be due to the CPU and associated
high speed circuits inside the PC.




...... Phil
Good call Phil,
Maybe I didn't say it clearly, but just plugging the ac cord in and
holding
it near the laptop induces noise on the power line. ( ac cord only, no
switching power supply attached)

"amdx"
"Phil Allison"
"Charles"

Switch-mode power supplies are dirty ... lots of harmonic energy. The
interference is both radiated and sent back into the ac mains.


** But they don't usually generate energy in the FM broadcast band (
i.e. 88 - 108 MHz) - that is more likely to be due to the CPU and
associated high speed circuits inside the PC.

Good call Phil,
Maybe I didn't say it clearly, but just plugging the ac cord in and
holding
it near the laptop induces noise on the power line. ( ac cord only, no
switching power supply attached)

** Validates my comment completely.



.... Phil