How to Conduct a Radio Club; Describing Parliamentary Procedure, Indoor and Outdoor Experiments, 5,000-Mile Receiving Set and Many Other Features (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1917 Excerpt: ...diameter. The complete plate, including the cooling flange, is 34 inches in diameter. The plates of a quenched spark gap cannot be constructed in a slipshod manner. They must be cast in a solid piece and very carefully molded. In fact, it is not sufficient that these plates be smoothly cast. They must be Flg. 61--Suggested Design for Pancake Oscillation Transformer. placed in a lathe or milling machine and ground to a smooth surface with extreme accuracy. If the sparking surface is uneven the spark discharge will take place at the highest point and finally short-circuit the gap. After completion these plates must be carefully mounted in a containing rack and placed under great pressure. The junior experimenter is accustomed to stack these plates between two insulating slabs and draw them together by means of iron.bolts. It is impossible to compress the plates evenly in this manner. As a matter of fact, efficient results cannot be expected unless the plates are mounted in a cast iron frame, properly insulated from it and pressed together by means of a large set screw on the end which acts directly upon the center of'the plates. In this manner a great pressure can be exerted, making the intervening spaces airtight. The dimensions for the insulating washers are given in Fig. 59, the suggested outline for the design of a gap container in Fig. 60, and a simple sketch of a suitable oscillation transformer in Fig. 61. Complete constructional details of the oscillation transformer are not given, but for amateurs' information it can be stated that they are generally constructed of strip copper, placed in slots cut in spiral form on a slab of hard rubber, bakelite or other insulating material. The Spiral Oscillation Transformer.--For operation at a wave-length of fro...