54 STAT.] MULTILATERAL-TELECOMMUNICATION-APR. 8, 1938 direction-finding stations must, in principle, be able to use it.1 In addition, they must be able to take bearings from emissions made on 500 kc (600 m), particularly to locate distress, alarm, and urgent signals. [753] (2) An aircraft station within proximity of a coast station and which calls the latter to obtain a bearing, must use the watch fre- quency of this coast station. [754] §13. The procedure to be followed in the radio direction-finding service is given in appendix 15. Potp.184 D. RADIOBEACON SERVICE [755] §14. (1) When an administration deems it advisable, in the Radobeaconeve interests of maritime and aerial navigation, to organize a radiobeacon service, it may use for this purpose: [756] (a) radiobeacons proper, established on land or on vessels permanently moored; the emissions of these radiobea- cons may be either non-directional or directional; [757] (b) fixed stations, coast stations, or aeronautical stations designated to function also as radiobeacons, upon re- quest of mobile stations. [759] (2) Radiobeacons proper shall use the following waves: [760] (a) In the European region, for the maritime radiobeacons, the waves of the band 290 to 320 kc (1,034 to 938 m) and, for the aeronautical radiobeacons, the waves of the band 350 to 365 kc (857 to 822 m), as well as certain waves of the bands 255 to 290 kc (1,176 to 1,034 m) and 395 to 415 kc (759 to 723 m) selected by inter- national aeronautical organizations. [761] (b) In the other regions, for the maritime radiobeacons, the waves of the band 285 to 315 kc (1,053 to 952 m) and, for the aeronautical radiobeacons, the waves taken from the band 194 to 365 kc (1,546 to 822 m). [762] (c) In addition, in Europe, Africa, Asia, the directional radio- beacons (maritime and aeronautical) may use the waves of the bands 1,560 to 1,630 kc (192.3 to 184.0 m) and 1,670 to 3,500 kc (179.6 to 85.71 m) under the conditions set forth in §23 of article 7 [No. 193]. A1'p1473. [763] (d) The use of type-B waves shall be prohibited for radio- beacons proper. [764] (3) Other stations notified as radiobeacons shall use their normal frequency and their normal type of emission. [765] §15. Signals sent by radiobeacons must permit of exact and accurate observations; they must be chosen in such a way as to eliminate all doubt when the question arises of distinguishing among them two or more radiobeacons. [766] §16. The administrations which have organized a radiobeacon service shall take all measures necessary to assure the efficiency and regularity of this service, that is, to have the transmissions made [758] 1 It is recognized that certain existing stations are not able to use this wave, but all new stations must be able to take bearings on 375 ke (800 m) and on 500 ke (600 m). 193470-41 -PT. ll ---22 1575
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