| 摘要 |
517,052. High-frequency transmission systems. STANDARD TELEPHONES & CABLES, Ltd. Oct. 31, 1938, No. 31442. Convention date, Nov. 16, 1937. Addition to 491,359. [Class 40 (iv)] [Also in Group XL] A high-frequency transmission circuit 105, Fig. 1, contains two loops 108 interconnected by an impedance such as an open line 111, a closed line, Fig. 2 (not shown), an inductance, Fig. 3 (not shown), or a condenser, Fig. 4 (not shown). By selection of the lengths # 1 , # 2 , # 3 , and the impedance 111, the network can be made to reject two frequencies and may be used to isolate a receiver from two local transmitters, Fig. 11 (not shown), or isolate each of three transmitters or receivers having a common aerial, Fig. 12 (not shown). When a concentric cable is used the impedance is preferably a condenser plate 621, Fig. 6, adjustable externally.of the cable. The impedance may be used to accurately tune the network to reflect a single frequency, or for matching, Figs. 7, 8; 9, 10 (not shown). Such a matching network in a transmission line may be used as a support for the line, Fig. 13. |
