. The Bell System technical journal . ween the crystal and wire vibrating sys-tems. Considerable work has been done in regard to the amount of soldernecessary and the most desirable shape for the solder cone. The completeassembly of a wire support for a crystal is shown in Fig. The shape ofthe solder cone shown in Fig. has proved to be the most desirable and hasbeen termed as bell-shaped. This type of cone formation allows the wireto be twisted in handling and still not break away the top of the cone andform an appreciable crater. For the purposes of analysis we may then as-sume that
. The Bell System technical journal . ween the crystal and wire vibrating sys-tems. Considerable work has been done in regard to the amount of soldernecessary and the most desirable shape for the solder cone. The completeassembly of a wire support for a crystal is shown in Fig. The shape ofthe solder cone shown in Fig. has proved to be the most desirable and hasbeen termed as bell-shaped. This type of cone formation allows the wireto be twisted in handling and still not break away the top of the cone andform an appreciable crater. For the purposes of analysis we may then as-sume that the cone becomes part of the crystal and moves with it so thatwhen computing the length of a wire vibrating in flexure, this length shouldbe determined from the top of the cone. The amount of solder used in thecone since it is part of the crystal must be kept at a minimum in order thatthe constants of the crystal equivalent circuit will not be modiiied too muchby it. One established fact of the effect of the solder in the cone on the. Fig. —Soldered lead type movinting. equivalent circuit is to raise the resistance in the equivalent circuit for thecrystal and this resistance increases considerably with an increase in tem-perature. The amount of solder permissible in the cone would then bedetermined by the maximum temperature at which the crystal is to be oper-ated and the minimum Q allowable. The type of motion that the crystalwould generate in the support wire when oscillating is that shown in by the dotted line. The solder ball shown to the right of the figure actsas the clamp for the wire. This solder ball may be placed at any point alongthe wire corresponding to a node. The diameter of this ball need only besufficient to act as a clamp. In general, this will be in proportion to the wirediameter. For example, at 200 kc it was necessary to use a solder ball 60mils in diameter on a diameter phosphor bronze wire. The spacingbetween the solder ball and the h
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Keywords: ., bookcentury1900, bookdecade1920, booksubjecttechnology, bookyear1
