My shack is on the second floor of my home, and I run a single operator, 2 radio contest setup. The two coax runs pass through the wall and drop down to an antenna switch approximately 15 feet from the radios.
The ground system consists of multiple copper ground rods driven in over a fairly wide area, bonded together with 4awg bare copper wire, and the ground then travels up the exterior of the house to the shack via a 1" wide copper braid, also about 15 feet long in total.
The coax shields are grounded to the same ground stakes that the antenna switch is grounded to, and there are polyphaser lightning arrestors located at the ground stakes.
K9YC and W8JI both recommend installing common mode chokes as close to the radio as possible, and connected to a low impedance ground line to prevent high power common mode signals from efficiently coupling to nearby electronics. I intend to do so using 1:1 common mode chokes right at the radio coax connector, bonded to the ground line, but neither mention bonding feed line runs together.
I'm trying to determine if there would be any advantage or disadvantage to bonding the shields of both coax runs and the ground line together at the bulkhead panel. On the one hand, this would reduce overall impedance of the ground connection, but on the other, it may provide a route that common mode current appearing on one conductor could bleed over on to the other conductors.
I will likely also include common mode suppression within the antenna switch itself, so the line should be fairly well isolated on both ends.
Should I use the bulkhead connectors and bond the lines together at the pass through plate (some 6 feet from the radios and 10 feet from earth), or use grommets to protect the coax as it passes through the hole in the aluminum panel, and bond the coax shield to the ground line only at the radio chassis and the antenna switch?