12V 76A PSU Mods Part 1

This 12V 76A PSU was purchased cheap off Ebay. It's from a Dell Server. 
Main issue (after finding the pinouts) was a high noise level on 28, 50, 70, 144MHz.
On inspection it seemed there was no real output filtering - presumably this is provided on the server motherboard. 

I found room to add an output filter and terminal block connections on one side of the case, close to the original output connector for easy wiring.

I also took the opportunity to isolate the output from the chassis (with a diode and resistor to stop it floating too far) so I can connect it in series with a second PSU to give me 26V/76A for LDMOS PAs. (With a large diode across each supply to prevent the output being reverse biassed when one of the supplies is not yet switched on). Isolation was easy on this PSU by drilling out two mounting holes to 3.5mm and inserting a TO220 top hat insulator in the holes.

Foil and Braid Coax Does Need to be Checked Regularly!

Picture of the foil shield of an old piece of Westflex, retired from use as it was getting kinky.
Used on a rotating system for quite a few years. Those comments on the forums have some merit!