High Frequency Apparatus Page 78

78 HIGH FREQUENCY APPARATUS cloth. These accessories on a work table, with the clean glasses and sheets of tin foil, will enable the worker to proceed. With reference to Fig. 6, the first plate of each unit is to have its foil sheet projecting to the left. This leaves a margin of ¾ in. on three sides. This first sheet of foil is to be secured to the plate in the following manner: Slightly warm the glass over the flame and immediately touch with the beeswax; spread the latter in a very thin layer with a tuft of cotton. Place the foil sheet in position and rub into perfect contact, using the dauber, and working outward with a circular motion. When this first sheet has been secured to the glass, the latter may be placed on the table with the foil underneath and projecting to the left. A touch of the wax to the upper side of the plate and the second foil sheet may be laid on; this is to project to the right with a margin of ¾ in. on top, bottom, and left side. Next comes a piece of warm glass with its drop of wax; then the third sheet of foil which projects to the left the same as sheet No. 1. On this is the third plate of glass, fourth sheet of foil, and so on until 10 sheets of foil and ten plates of glass have been assembled as shown in Fig. 6. The object of the drop of wax is merely to insure that the glass and foil sheets will maintain their relative positions during assembly. The unit is now to be “backed up” on either side with a piece of cardboard. The projecting lugs are rolled up with a piece of ½ in. copper ribbon enfolded, and the entire unit bound firmly with linotape at top and bottom. This general procedure is to be followed with each of the 20 units which will then be ready for impregnation. In a double boiler, melt equal parts of beeswax and