INTERNATIONAL AGREEMENTS OTHER THAN TREATIES [54 STAT. (38) CHANNELS: The term "channels" means the portion of the radio spectrum of a width sufficient to permit of its use by a radio station for communica- tion purposes; it comprises the following three elements, all defined below: 1) the "frequency band of emissions". 2) twice the specified "frequency tolerance". 3) the "interference guard bands", if required. (39) FREQUENCY BAND OF EMISSION: The term frequency band of emission, means that the frequency band of an emission is the frequency band actually occupied by this emission for the type of transmission and for the signalling speed used. (40) INTERFERENCE GUARD BANDS: The term "interference guard bands" means the frequency bands additional, to the frequency band of emission and frequency toler- ance, which may be allowed in order that there shall be no interfer- ence between stations having adjacent frequency assignments. In general this provision is dependent upon receiver selectivity and transmitter characteristics. (41) PRIMARILY: The term "primarily" used in connection with certain bands in the allocation table of this agreement means that as duly authorized installations of the primary services are undertaken, they will have preference on the available channels in that particular band. The assignment of channels to other services in the general alloca- tion for each of these bands will be carried out in such a manner as to prevent undue interference with existing stations of the primary service. (42) FACSIMILE BROADCAST STATION: A station licensed to transmit images of still objects for record reception by the general public. SECTION 8. AMATEURS Amateurs. The following provisions concerning amateurs were unanimously agreed upon in addition to the allocation tables: 1. That the band from 1750 to 2050 kc. be allocated for A-1 and A-3 emissions. 2. That, after a study of the recommendations issued by the Radio Conference at Buenos Aires, (revised at Rio de Janeiro, 1937) e) and J) of Recommendation number 10, they have agreed to amend them, without altering the spirit thereof, substituting in their stead, the following: e) That the Administrations should point out the convenience that amateurs use the bands from 1750 to 2050 and 3500 to 4000 Kc/s preferably for short distance communication. 2528
�
