High Frequency Apparatus Page 189

THE CONSTRUCTION OF LARGE APPARATUS 189 diameter to the shank of the clip. A piece of fibre tubing, making a tight fit over the shank, is then forced on and extended over the binding of the wire. This serves as a protection for the cable where it is joined to the connector and provides a suitable handle as well. In Fig. 4 is given a diagram of the connections of the complete transformer and the reader will note that the connection to the primary spiral is variable over quite a wide range. In operating the transformer, it is necessary to make various trials in order that the correct number of turns to produce resonance may be determined. The point at which the secondary coil makes contact with the inside turn of the primary should always be grounded on the nearest water pipe. This will not only safeguard the perFig. 4. Diagram of connections for the oscillation transformer