High Frequency Apparatus Page 238

238 HIGH FREQUENCY APPARATUS Low Voltage Condensers. These condensers are tested for a voltage of 500 and have a special grade of wax paper dielectric coated with foil. The condenser measures 5 inches high, 2½ inches wide, 34 inch thick, and may be used on telephone circuits, across the vibrators of induction coils to prevent sparking, across mains supplying high frequency apparatus to prevent surges, and for a wide variety of similar purposes. Cat. No. E. S. 355. Condenser, capacity 2 microfarads, price, $0.90 Prices of other capacities on application. Marble Bases. Finest quality "Electric Blue" marble bases, polished on one side and all edges, top edges are slightly bevel. Base, 3 inches by 5½ inches, ½-inch thick....$0.70 Base, 3½ inches by 6 inches, 8-inch thick.... Base, 5 inches by 9 inches, 8-inch thick.. Cat. No. 56. Cat. No. 57. Cat. No. 58. . Flexible Couplings and Hubs. Cat. No. 61. These flexible couplings are useful for driving any device which it is desired to connect directly to a motor without accurately lining them up, such as connecting a small dynamo to a motor or water motor, synchronous spark gaps, etc., not requiring over 1/10 H.P. Always give diameter of both shafts in ordering. Price of Coupling, complete Cat. No. 62. Hub only (being one side of coupling No. 61), to which a disc or any other device may be screwed for rotating same on motor shaft. Give size of shaft when ordering. Price, each .70 1.05 .$2.50 1.00 Insulating Materials. Cat. No. 60. Friction Tape, best quality, large half pound roll. Each .$0.23 Cat. No. 60A. Friction Tape, in small ounce rolls.. Cat. No. 61. Oiled Linen Tape, 1 inch wide. ("Linotape") .03 Per yard, .05; per roll, 72 yards. 1.50