Suggestions for an Arrangement Between the United States, Canada, Cuba, Mexico, and Other North American Nations Relative to the Assignment of Frequencies on the North American Continent3

(1) The sovereign right of all nations to the use of every radio channel is recognized.

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Nevertheless, until technical development progresses to the stage where radio interference can be eliminated, it is agreed that special administrative arrangements are essential in order to promote standardization and to minimize radio interference.

(2) The Governments agree that each country shall be free to assign any frequency to any radio station within its jurisdiction upon the sole condition that no interference with any service of another country will result therefrom.

(3) It is agreed that each Government shall use Appendix I attached hereto, as a general guide in allocating channels to the various services specified therein.

(4) Channels are divided into two classes (1) common channels which are primarily assigned to particular services in all countries, and (2) general communication channels which are assigned for use in specific areas.

(5) With regard to the general communication channels, it is considered that at the present stage of the art, the use of radio channels below 3500 K/C will not normally cause interference at distances greater than 1000 miles and such channels may, therefore, be used with freedom from interference by stations separated by such distance. It is further recognized that stations operating on frequencies above 3500 K/C may become sources of interference at distances in excess of 1000 miles, particularly at night.

(6) The Governments agree to take advantage of the physical facts just explained, and by suitable geographical distribution of these two classes of channels throughout North America and the West Indies, to make available for general communication services, the total number of channels set forth in Appendix 2 attached hereto.

(7) Each Government shall have the right to assign to stations under its jurisdiction, in the manner it deems best, such general communication channels as are allocated to that Government under this agreement, as set forth in Appendix No. 2. The Governments agree not to assign to stations within their respective jurisdiction any of the general communication channels allocated to other Governments, unless it can be accomplished without causing interference.

(8) The marine calling frequency of 5525 K/C shall be used until superseded by an international assignment.

(9) In addition to the frequencies assigned specially for experiments (1604, 2398 and 4596 K/C) the Governments agree that experimentation by particularly qualified experimenters, may be authorized on any other channel provided no interference is caused with established services, as provided in Regulation No. 11 of the International Radio Convention of Washington 1927.4

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(10) The Governments agree to adopt a radio frequency standard based on the unit of time, and to compare at least once every six months, the actual radio frequency measuring standards.

(11) The Governments agree to require all stations, other than mobile and amateur stations, under their jurisdiction, to tune their transmitters with an accuracy of 0.025 percent, or better, of their national frequency standard.

(12) The Governments agree to require all stations, likely to cause international interference, other than mobile and amateur stations, to maintain their frequency with an accuracy of 0.05 percent, or better, at all times.

(13) For the purpose of this agreement a channel shall be regarded as a band of frequencies the width of which varies with its position in the range of frequencies under consideration, but which progresses numerically from the lower to the higher frequencies, as shown in the following table:—

Frequency (K/C) Channel Width (K/C)
1500–2198 4
2200–3313 6
3316–4400 8
4405–5490 10
5495–6000 15

(14) The Governments agree to adopt for the present in their national plan of allocation a separation of 0.2 percent between radio frequency channels; and to permit stations under their respective jurisdiction to occupy the assigned frequency and the adjacent frequencies to the limit permitted by the frequency maintenance tolerances and necessitated by the type of emission the station may be authorized to use. For commercial telephony a band width of six kilocycles shall be permitted. For the present, a 100 kilocycle band width shall be considered standard for television.

(15) The Governments agree to require stations under their jurisdiction to use transmitters which are as free as practicable from all emissions (such as those due to harmonics, decrement, spacing waves, frequency modulation, key clicks, type of keying, mush, etc.) not essential to the type of communication carried on, and which would be detrimental to communication being carried on by stations in other countries.

(16) Appendices Numbers 1 and 2, together with the chart showing graphically the distribution of the frequencies which are attached hereto, shall constitute a part of this agreement.

(17) This agreement shall go into effect on March 1st, 1929, and shall remain in force until January 1st, 1932, and thereafter for an indeterminate period and until one year from the day on which a denunciation thereof shall have been made by any one of the contracting parties.

  1. This draft, prepared by a subcommittee of Committee No. 2 of the Conference, was transmitted to the Department in a letter of February 11, 1929, from E. O. Sykes, the chairman of the American delegation. For texts of appendixes and chart mentioned as attached, see Department of State Treaty Series No. 777–A.
  2. Foreign Relations, 1927, vol. i, p. 288; also Department of State Treaty Series No. 767.