Replacing failed powersupplies on qbus PDP-11s

[Tony Duell]

> 
> On 30 Jan 2009 at 16:41, Roy J. Tellason wrote:
> 
> > Eh?  Why would it do that?
> 
> Read about it:
> 
> http://www.smpstech.com/filter00.htm
> 
> Interestingly, the real-world example cited is the addition of an=20
> input filter to a PDP 11/40...

Which would be curious if true, since no standard PDP11/40 used an SMPSU. 
Switching _regulators_, sure, but the PSU starts with a large 
mains-frequency transofrmer, which is not going to have much of an HF 
response.

Howev,er I read the article as that the author had run some simulation 
software on an 11/40 to study the preformace of another PSU. And that 
makes a lot mroe sense.

-tony