High Frequency Apparatus Page 88

88 HIGH FREQUENCY APPARATUS winding, firm and smooth and it serves further to aid in the insulation. The winding, when completed, is given a liberal coating of armalac. The starting and finishing ends of the winding are soldered to lengths of incandescent lamp cord which are subsequently joined to the primary binding posts. Secondary Winding.-The secondary data is given in Fig. 4. This winding is of enameled wire and the method of procedure is identical with that of the primary. The same form is used and the winding started upon a heavy layer of micanite sheeting cut 2½ in. wide. In all, this insulation should be about in. thick. The top turn of micanite is covered with several layers of oiled paper, after which the winding may start. Before starting the paper turns over the micanite, the builder places a strip of thin copper ribbon across the micanite. Over this the paper is wound. The starting end This diam. for 60-only Secondary data For 5000 volts 25~ 32000 turns #34 en 60~ 16480 Turns 32 en 8240 125~ turns #32 en Fig. 4. Data for secondary winding