Short shafts arrangement for the transition of an asymmetrical high frequency line in a symmetrical arrangement

摘要

438,506. Wireless signalling; aerials. PERCIVAL, W. S., 6, York Mansions, York Avenue, Hanwell, and WHITE, E. L. C., 32, The Rise, Hillingdon, both in Middlesex. Feb. 15, 1934, Nos. 5102 and 22023. [Class 40 (v)] Relates to high-frequency feeders for shortwave wireless aerials, of the type in which a central conductor is contained within an outer conductor in the form of a sheath, and consists in the provision of auxiliary members designed to increase the impedance of the central wire and sheath in parallel so as to attenuate undesired waves picked up by the outer sheath, such as would cause interference in reception or such as would vitiate a required directional field in transmission. As shown in Fig. 1, auxiliary conductors 11, 12 having a length one-quarter (or an odd multiple thereof), of the undesired wavelength are connected, at or near the two spaced aerials 8 to the outer sheath of the feeder 1, 2, and act as attenuators, absorbers, or rejector circuits. In Fig. 4 the auxiliary conductor takes the form of a bifurcation 16 connected at 17 to the central conductor 2, as shown, the thickened end portion 18 of the latter serving as an impedance transformer. The members may be coupled to the sheath 1 through a capacitive or inductive impedance according as they are made shorter or longer than an odd multiple of one quarter of the undesired wavelength. Specification 414,296 is referred to.