It is very important that a good ground connection be secured for wireless instruments. A good ground is absolutely necessary for the proper working of the apparatus. Amateur experimenters usually use the water or gas-pipes for a ground, and fasten the wires by means of a ground clamp such as shown in Figure 200. In the country, where such pipes are not available, it is necessary to bury a sheet of copper, three or four feet square, in a moist spot in the earth and connect a wire to it.
The Receiving Apparatus
The receiving instruments form the most interesting part of a wireless station and usually receive first attention from the amateurs. They are the ears of the wireless station and are wondrously sensitive, yet are very simple and easy of construction.
The instruments necessary for receiving are:
A Detector,
A Tuning Coil or a Loose Coupler,
A Fixed Condenser,
A Telephone Receiver.
Other devices, such as a test buzzer, variable condenser, etc., may be added and will improve the outfit.
After the aerial has been properly erected, the first instrument necessary to construct will be either a tuning coil or a loose coupler. It is a good plan to make a tuning coil first, and a loose coupler after you have had a little experience with your apparatus.