High Frequency Apparatus Page 201

THE CONSTRUCTION OF LARGE APPARATUS 201 Meory lines • glass Light tinfoil Fig. 14. Single plate of the condenser coated on both sides with tin foil tions with the outside of the case are by means of heavy flexible cables made by binding a number of strands of fine insulated copper wire under one cover. Setting Up and Operating.-The connections of the apparatus are simple as the accompanying drawing shows, and it is only in some few particulars that the author need supplement with further explanation. (See Fig. 15.) A switchboard is highly desirable but not at all essential to the successful operation of the apparatus. One may be made quite simply and without the expenditure of much time or money. A pilot lamp, to enable the operator to see the control switches in the dark; a 50 ampere double pole, single throw knife switch to control the transformer circuit; and a small snap or knife switch for the spark gap motor circuit, will complete the equipment of such a simple board. This adjunct to the outfit may be made quite elaborate, if desired, just for the theatrical effect it may have if placed upon the stage. In this event, the board, which may be of wood treated with a fireproofing compound, should be finished eventually in a dead black to simulate slate. The switch equipment may be supplemented with fuses, imitation bus-bars and additional lights. An ammeter and a voltmeter will not only add to the appearance, but will also be of practical service in the operation of the apparatus.