How about the fact that your shack is connected to the ground rod outside through the coax AND to the electrical wiring through a three prong plug? Isn't that two paths?
Well butter my butt and call it a biscuit, at least one ham figured it out. The biggest mistake hams make is listening to foolish uncle Elmer and planting a ground rod outside the shack and bringing the coax and a ground inside. You have placed yourself in a Ground Loop between two earth grounds. You intentionally violated electrical codes and all best practices and begging for noise and lightning problems. You got what you asked for, one dangerous noisy mess brought to you by Uncle Elmer.
When you place a rod outside the shack. The next thing you do is run a long wire all the way through your house up through the walls up into the attic/basement to the ground rod placed under your AC service. You just provided a perfect path for lightning and common-mode noise to flow through your home. You do not have a ground. All you have is two rods with a piece of wire you call a radio connecting the two rods together placing you hopelessly lost in a Ground Loop you cannot get yourself out of. That loop acts as an antenna allowing any and all currents to flow through your radio. Then when lightning comes to visit, those two rods difference in potential rises to thousands of volts, and then thousands of amps of equalizing current flows through that wire you call a radio.
The solution is so simple, Uncle Elmer cannot figure it out because he is stuck in the 60's. He never noticed technology and electrical codes changed 50 years ago after the carnage of dead burnt bodies and equipment piled up. Electrical codes are written in blood ink.
Follow code and best practices. Instead of running your coax directly to the shack from the tower or tree, run it to your AC service entrance. Supplement your AC service ground with more rods if you want. Run a bare #6 AWG buried as deep as you can away from the house with your coax to the tower base and bond it to the tower ground. At th eAC service bond your coax shield to the AC Service Ground using an antenna discharge unit. From that same point run the coax inside to the shack along with a Insulated #6 AWG copper wire for your station ground.
Do that and you have a Single Point Ground. There is no path for lightning or noise to flow. With SPG all equipment remains at the same potential. No voltage means no current or noise. Stupid simple electrical principles.
