High Frequency Apparatus Page 172

172 HIGH FREQUENCY APPARATUS the apparatus if it is permitted to strike in for any length of time. The shed should contain a substantial wooden table along the rear wall facing the door, and upon this table the apparatus is arranged in the order shown in Fig. 21. The floor of the shed should be at least one foot above ground and an open air space should be left beneath in order to frustrate dampness so far as is possible. A simple and good construction is to build the shed around four substantial corner posts, starting the walls a foot above the ground. The roof should have a generous slant to shed the rain. With reference to the first drawing, the apparatus is arranged in the following order, left to right: Transformer, spark gap, condenser and oscillation transformer. Upon the wall to the left is secured the main switch, which should incorporate a cut-out fitted with 15 ampere plug fuses. To this switch from the outside of the shed, lead the line wires, which are to be supplied with a 110-volt, 60cycle alternating current, preferably from the local central station. Beside the main switch, the switch for the spark gap motor should be located. The primary terminals of the transformer are to be connected with the main switch, as shown in the wiring diagram below, which also shows the connections for the remainder of the apparatus. From the secondary terminals of the transformer pieces of No. 14 rubber-covered wire lead to the terminals of the spark gap. From one terminal of the spark gap a piece of stranded cable, composed of 100 strands of about No. 24 insulated magnet wire, runs to one terminal of the condenser. From the other terminal of the condenser, a piece of the stranded cable leads to the movable clip on the primary of the oscillation transformer. The second terminal of the spark