GB579782A - Phase changers - Google Patents

Abstract

579,782. Phase-shifters. STANDARD TELEPHONES & CABLES, Ltd. Dec. 3, 1943, No. 20392. Convention date, Jan. 8. [Class 40 (iii)] A phase-shifter with constant surge impedance, but phase-shift that can be varied without the use of wiping contacts, is adapted for insertion in a high-frequency transmission line. The latter comprises ingoing and outgoing pairs of conductors 78, 78<1>, Fig. 2, connected (Fig. 4, not shown) respectively to the top and bottom ends of a pair of parallel conductors 40, 40<1>, Fig. 3 (transverse section), which are thus inserted in the line, but are more widely spaced (Fig. 5, not shown) than the line conductors. Between and parallel to the conductors 40, 40<1> is a control member comprising a metal part 46 screwed to a dielectric part 48. This member is movable (vertically in Fig. 3, right or left in Fig. 2) and is so shaped that the product of distributed inductance L and capacity C varies with the movement, causing a. phase-shift, while the surge impedance L/C remains constant. Alternatively, the metal and dielectric parts of the control member may be wedge-shaped in section, Fig. 6 (not shown). The control member is geared to a handle 62 and movement is indicated by a pointer 96 which is connected to the control member by linkwork.