As Derrick, @KF5LJW has drilled into our heads the problems created by having a negative-ground bond in our DC power supplies, it got me to thinking that multiple negative ground radios sharing the same supply could have the same problems. Radio 1 and radio 2 share the same DC supply, both have there respective antenna coax shields bonded to AC service ground per NEC. The neutral-ground bond in the power supply has been removed, but each radio has an alternate path for current to flow to the other radio, from its negative wire -> printed circuit board ground plane -> to chassis through mounting screw and/or SO-239 -> up the coax to the bonding point -> down the coax to the other radio drawing high current on transmit. For example, I measured 17.9A on the negative lead of radio 1 in transmit, and 2.6A DC current on the coax, which came through radio 2, for a total of 20.5A. I suspect if it was a major issue, we would hear of more radios being damaged because of this, but it still bothers me that some of the supply current is flowing though the other radio. Changing the length, wire sizes and arrangement can change the ratio between current supplied by the power lead vs the coax, but I can't conceive of a perfect setup besides one power supply for each rig.