100 amp sub-panel service

[k4kyv]

Yes, it's like driving a square peg into a round hole.  I just let all my neutrals float free, treating them exactly the same way as I would a hot wire, with separate earth ground on all equipment.  I believe that's that's exactly what the NEC says to do.  Any current on the earth or safety ground will set up a potential difference between any two units connected to that  line, and that is what causes ground loops.

You theoretically shouldn't  have any ground  loop  hum if the chassis on everything in the shack is exactly at zero potential.  But even then any closed ground loop would be equivalent to one large turn of wire, and would pick up hum and noise induced from nearby magnetic disturbances caused by transformers, motors and random electrical transients.

The "star" grounding system to a single point should be less prone to cause hum pickup than daisy-chaining all units to one continuous ground lead.

But sometimes,  the very measures that eliminate or reduce induced a.c. hum in the audio stuff will actually introduce or increase tunable hum on rf signals heard in the receiver, or cause rfi from the transmitter to affect other stuff, and vice versa.

[ka3zlr]

Well my question was about installing a 100 amp sub panel over at the other workshop desk wall for the 813 machine, what I did prior was just run a rather long length of cable back to the main panel, I want to stop doing that...and i did...

The idea is when i leave the station i want to throw a switch and completely disconnect the xmitter from any service.. all grounds and all antenna...after discharging the main HV supply...completely isolate the machine...

[WA1GFZ]

good idea