METHOD OF TESTING RATIO DIRECTION FINDING STATIONS WITH ADCOCK ANTENNAE SYSTEMS

摘要

1528034 Testing direction finding apparatus LICENTIA PATENT VERWALTUNGS GmbH 20 Oct 1975 [31 Oct 1974] 43022/75 Heading H4D An Adcock direction finding system comprising a circular array of antennae is tested by positioning a test antenna at the array centre and transmitting therefrom a HF test signal which is received by respective Adcock pairs of antennae in the array and analysed by the associated direction finding circuitry whereby imbalances and faults in the Adcock systems may be located. Antennae 1-8, Fig. 1, are utilized in pairs of diametrically opposed elements the signals from which as received from antenna 9 energized by transmitter 10, are fed to Adcock processing unit 11, from which output signals U H , U OW and U NS which are respectively, the total of the sum voltages produced by each Adcock pair, U NS # U.sinα, U OW #U.cosα where U is the sum of the Adcock pair difference voltages for a received signal at a bearing angle of α. A test device 12 is interposed in the circuit connecting these output signals to a directional receiver 16 by which the direction of the received signal is measured. Device 12 includes a plurality of ganged switches, S1-S6 which permit, in one position, normal operation of the system, and in another position, feed signals U H , U OW , U NS through summer 13 and power dividers 14 and 15, as illustrated, whereby if, under normal operation, U OW # U NS # O, the total voltage U H is split by divider 14 and then further split equally into outputs El and E2 producing a 45 degree bearing angle in the receiver 16. Under fault conditions, the equal strength signal received at each antenna, is for example attenuated in one channel, say 7', and therefore difference signals U OW and U NS are an order of magnitude of U H , whereby a bearing angle differing from 45 degrees is obtained in receiver 16 due to differing values of voltages El and E2. The faulty part of the system may then be detected by systematically removing from circuit, individual parts of the system. A second embodiment is also described.