────────────────────────────────────────────────────────────────── Size of Coil D K J ────────────────────────────────────────────────────────────────── 1/4 in. 3 in. 2 1/2 in. 1/2 in. ────────────────────────────────────────────────────────────────── 1/2 in. 3 in. 2 1/2 in. 5/8 in. ────────────────────────────────────────────────────────────────── 1 in. 3 1/2 in. 3 in. 5/8 in. ────────────────────────────────────────────────────────────────── *The Condenser* consists of alternate layers of tinfoil and paraffined paper piled on top of each other and then rolled up. Four sheets of tinfoil, thirty-six inches by two and three-quarters inches wide will be required. Eight strips of waxed condenser paper, three and one-quarter inches wide and thirty-six inches long are necessary. Lay one sheet of paper out flat on a table or board and place a sheet of tinfoil over it. The tinfoil should be along the centre of the paper strip so that there is a one-quarter inch paper margin along the sides. One end of the tinfoil should project over the end of the paper about two inches. Lay two sheets of waxed paper over the tinfoil making them line up with the first paper sheet all around. Then place another strip of tinfoil on the paper. It should be directly above the first sheet of tinfoil, but the end of the tinfoil must overlap the paper by two inches at the opposite end from the first sheet. Place two more sheets of paper over the tinfoil and on top of that a third strip of foil. The third strip of foil should line up exactly with the first strip. Then lay two more sheets of waxed paper over the third sheet of foil and place the fourth sheet of tinfoil in position making it exactly line up with the second sheet. Place a single sheet of paper on top. The result should consist of four sheets of tinfoil insulated from each other with two strips of paper between each two strips of foil. Connect the first and third sheets together with a wire and the second and fourth sheets likewise. Cut out a piece of cardboard, one and one-quarter inches wide and three and one-quarter inches long. Lay the cardboard on one end of the condenser and roll the condenser up around it very tightly. Tie it with a piece of string to keep it from unrolling, and dip it in some melted paraffine. Then place it between two boards with a weight on top so as to press it out flat.