Topband: switching pwr supply noise problem

[Zoltan.Pitman@libertel.nl]

Hello,

Before you start buying and installing external filters, I recommend to open
up the noisy PS itself and take a look at the mains connection. You will
often see the AC filter included in the PCB design but the filter itself is
not built in - the capacitors are left out and the connection points of the
coils are shorted over. 

The suitable components (I tend to use 1nF/400V and 100 uH) you can buy
yourself in Radioshack-like store for cents or take them out from scrapped
old equipment. 

Recently I had to track down some noise sources in my neighborhood. What I
found a real shame that this problem occurred not only at the cheap
aftermarket models but in products of well-known brands like Phillips, Sony
or Compaq.

Best regards,

Zoli HA1AG






> I have had good luck fixing these noisy computer power supplies by
> putting a high quality AC line filter in the computer AC line 
> cord. The
> W3NQN AC line filter and the ICE AC line filter work great.

<snip>

> I sure wish the FCC would mandate strict standards (European power
> supply RF filtering is much better) for how much switching supply
> garbage can be emitted down the neutral (ground) of the AC 
> service. 160
> and 80 meters would be a much cleaner place!
> 
> 73,
> Tim K3LR

> > Anybody have any suggestions on quieting those little noise
> > generator power supplies? My only thought at the moment is to
> > build new transformer supplies or to substitute an old computer
> > power supply that is RF quiet.
> >
> > Thanks for any suggestions,
> > Rod
> > VE7VV