[UK-CONTEST] "quietening" computer PSUs

[Clive Whelan]

A tad off topic ( again), please excuse.

After a very frustrating time on 14Mhz in WAE, when I
struggled to copy many of the weak US stations calling, I've
discovered that the PSU in my new shiny Pentium dual core
computer is a tad noisy, and although clean at 50Mhz, begins
to be dirty below 21Mhz.

There is no doubt that direst radiation into the antenna-
which is quite [too] close- is responsible from tests I have
now carried out. Using ferrite on the mains lead does
nothing, but since the case is all metal, and the DC cables
are not exposed, I'm not quite sure from where the radiation
is coming. I have yet to have the case off, but assume that
the PSU must meet CE regulations, which however (I assume)
protect only VHF+ and not HF? The problem is detectable when
just the primary is connected to the mains, but is
unacceptable when the processor is working hard in Windows.

So, I suppose I am looking for tips from someone who has
been where I am going.


tia


73


Clive
GW3NJW