The best suited type of ground for minimal-frequency apps could be the single-position ground. The return currents in the three circuits will move with the common floor impedances linking the circuits. Conduction Coupling takes place when EMI emissions are passed along conductors (wires, cables, enclosures, and copper traces on PCBs) https://hud-helmet63199.blogs100.com/31685738/5-simple-statements-about-fn3258-130-35-explained