Well for one I think it voids most scope warranties.

Now look, floating the DUT makes much more sense, there are very very few instances where you have to create that hazard, and anywhere civilized with regulations on this **** will require your area to be cordoned off so people cannot wander in. Grounds can be a very complex topic.

Now one thing, if you find two 100WPC amps that are really fried out you can probably make an nice isolation transformer out of them. the voltage might not be perfect but god enough for testing.

Some people may disagree here, but once you re out of the hot side you no longer need the isolation. for example I am working on a Crown and it has a SMPS power supply. I have to fix that. then Iher a something little wrong in it and now I am working on the cold side. now as long as you have your wits, and are not going to fsall and drown in a bowl of soup (Mary Hartski) you know where the hot side is, if not forget working on this ****. Where the cord goes ??? MAYBE ?

I was working at a place, cement floor and on BIG TVs, many ties working on the floor. Well **** happened and I made them get an isolation transformer.. "You get a isolation transformer in here NOW. WHY ? If you don't I am going down to the hospital after a shock and claim I can never work in my field again for fear and sue you for every ****ing thing you got, BECAUSE YOU ARE SUPPOSED TO HAVE ONE !". Two days.

Th only time you really have to float the scope, and there are, if you are in an industrial setting working on ike Fanuc or some type of NC or CNC, or on something in the plant like some thing that controls motors n ****. the need COULD arise. But you are not doing that. If you were you would not be here asking.

In any unit you ever work on, of course if you have to work on the hot side get the transformer. And you make sure you know where the hot side is inside.

Enough for now. just find transformers at least six amps with secondaries adding up to the line voltage. Cheapest and easiest way.