KCBS Transmitter

So... you put up all of your towers. Now whatcha gonna do? Turn on the transmitter? Nope. It's time to put in the ground system for the towers. The ground system consists of copper wire buried in the ground fanning out around the tower in a circle. They are usually spaced three degrees apart, so you end up with 120 of the little devils in the ground. The ground wires act as a mirror image of the antenna to help with ground wave radiation, this is the most important signal for listening in the stations coverage area.

Here you can see the tractor that is being used to put the radials into the ground. The funny looking attachment in front of the tractor is a vertical blade. The blade has a hole in it that the wire passes through. The blade digs into the ground and as the tractor moves wire is pulled through the hole in the blade and buried. The blade can be moved up and down to control the depth of the wire. Look here for a closer look at the vertical blade. All of the wires are brought back to the tower and bonded to the ground strap (a flat piece of copper) around the tower. In a directional array like ours, the radials would overlap where they cross the circle from other towers. To avoid this overlap, wherever radials cross they are bonded together with ground strap. Radial length is about 90 degrees of the wavelength, so at 740 kilocycles, the ground radials extend out about 320 feet from the tower.

Updated 12/8/98