From: phil_a@tpg.com.au   
      
   "Trailboss"   
   >   
   >I am setting up my test bench.   
   >   
   > I have a variac with an iron vane ammeter and volt meter to serve the DUT.   
   > (usually tube amp). some older live chassis stuff too.   
      
   ** Live chassis tube amps or something else like TV sets ?   
      
      
   > My question is how to deal with my other mains powered test equipment,   
   > these include:   
   >   
   > HP sine generator   
   > Distortion analyzer   
   > VTVM   
   > Old tube Tek scopes   
   > Newer Philips scope   
   >   
   > If these units are all converted to three wire polarized plugs should just   
   > the scope sit on an Isolation transformer?   
      
   ** Never earth isolate ( ie float) your scope, that is very dangerous.   
      
   No need exists for an isolation tranny, with the exception of servicing   
   modern SMPSs and a few TV sets.   
      
      
   > Should the device under test chassis ground bypass the variac and go   
   > directly to the mains outlet?   
      
   ** Huh ?   
      
   The variac should have a 3 pin outlet fitted with mains ground.   
      
      
      
      
   ...  Phil   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)