My house is on solid rock, limestone I think, and is made of concrete and steel re-bar. This is the construction technique here in Israel. My ham shack is now on the top floor, three stories above the back yard. I have two ground rods where we had to dig and break rock to get them into the ground. On each of the house at street level are two copper tabs, 4" x 2" x 1/4 " sticking out of the wall labeled electrical ground. The builder must have tied the ground buss from the electric to these two bars sticking out on each side. Is this ground the best I can do for a ground in this soil?