Page:United States Statutes at Large Volume 54 Part 2.djvu/209

 54 STAT.] MULTILATERAL-TELECOMMUNICATION-APR. 8, 1938 this indication, there shall be given, in parentheses, the approximate length in meters. In the present Regulations, the approximate value of the wavelength in meters is the quotient of the number 300,000 divided by the frequency expressed in kilocycles per second. ARTICLE 6 Quality of Emissions [69] §1. The waves emitted by a station must be kept on the author- ized frequency as exactly as the state of the art permits, and their radiation must be as free as practically possible from all emissions not essential to the type of communication carried on. [71] §2. (1) The state of the art in the various cases of operation is defined in appendixes 1, 2, and 3, concerning the exactitude of the frequency, the level of harmonics, and the width of the frequency band occupied. [72] (2) Concerning the widths of frequency bands occupied by emissions, in practice, the following conditions must be taken into account: [73] 1. Width of the band as shown in appendix 3. [74] 2. Variation of the frequency of the carrier wave. [75] 3. Other technical conditions, such as the technical possibilities with regard to the form of filter-circuit characteristics, both for transmitters and for receivers. [76] §3. (1) The administrations shall frequently check the waves emitted by the stations under their jurisdiction to determine whether or not they comply with the provisions of the present Regulations. [77] (2) International cooperation in this matter shall be sought. [78] §4. In order to reduce interference in the frequency bands above 6,000 kc (wavelengths below 50 m), the use of directive-antenna sys- tems is recommended when such use is compatible with the nature of the service. ARTICLE 7 Allocation and Use of Frequencies (Wavelengths) and of Types of Emission [79] §1. Subject to the provisions of §4 (3) below [Nos. 86,87,88, and 89], the administrations of the contracting countries may assign any frequency and any type of wave to any radio station under their jurisdiction on the sole condition that no interference with any service of another country will result therefrom. [80] §2. However, the administrations agree to assign to stations which, by their very nature, are capable of causing serious interfer- ence with the services of another contracting country, frequencies and types of waves, according to the type of service they operate, in con- formity with rules for allocation and use of waves, as set forth below. 1429 Quality of emissions. Post, pp. 1689, 1593, 1595. Pot, p. 1595. Allocation and use of frequencies, etc.

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