[Elecraft] [OT] Grounding negative side of power supply?

[Joe Planisky]

Hi folks,

The recent discussions about bonding equipment together to reduce  
noise has prompted me to ask a question I've been mulling over for a  
few days now.

Should the negative side of a power supply be connected to the supply  
chassis (and thus to the "green wire" AC ground), or should it be left  
floating?  I have heard arguments both for and against floating the  
negative terminal, mostly from the fields of industrial control and  
precision sensing.  The gist seems to be that the negative side of  
power supplies are usually connected to chassis or structure ground  
except in cases of very sensitive analog sensing where it is sometimes  
left floating to help reduce noise.  I've heard stories of hum in  
repeater systems being cured by floating the negative side of the  
supply.

Does whether or not the negative side of the supply is floating affect  
the idea of bonding the rig and PS cases to a common point?

73
--
Joe KB8AP