As all other sorts of ground, the ground for the radio receivers is being accomplished by connecting the receiver ground (point Z on Pic.3.1) to Earth over a coper wire. You can live without the ground but the reception is much better with it though, especially considering simple devices, such as one at the Pic.3.1-a. Water plumbing is an excellent ground (central heating pipes are not), but it is most often inappropriate for use. There is no housewife that would agree to have some dreadful wire stretched across the house, from bathroom to the living room! House electrical installation's ground is excellent, but it should be used under NO circumstances, since life-threatenning danger from electrical shock exists. If you live on a ground floor, and there's plain soil beneath your window you can make your own ground by sticking a piece of water plumbing in it, acc. to Pic.3.4. The pipe should be about 80 cm long, and on its end you should connect the receiver ground, attaching it with a metal ring and a screw with the nut.