ATLANTIC CITY FOOTNOTES-continued prescribed in article 34 of the Radio Regulations (Atlantic City, 1947).

(149) For the explanation of the terms "Aeronautical mobile (R)" and "Aeronautical mobile (OR)" see 256 and 257.

(150) For the conditions of use of this band by the broadcasting service see 243, 244 and 250-254 (in article 5 of the Radio Regulations, Atlantic City, 1947).

(151) In Region 2, provision will be made for coastal telegraphy in the maritime mobile service by special arrangement.

(152) The standard frequency is 2500 kc. (155) The band 4063-4438 kc may be used, exceptionally and on the essential condition that harmful interference is not caused to the maritime mobile service, by fixed stations of mean power not exceeding 50 watts communicating only within the national boundaries of the countries concerned. the time of notification of these cases the attention of the International Frequency Registration Board is drawn to the above condition.

At

(156) The standard frequency is 5000 kc. (157) The band 6200-6525 kc may be used, exceptionally and on the essential condition that harmful interference is not caused to the maritime mobile service by fixed stations of mean power not exceeding 50 watts communicating only within the national boundaries of the countries concerned. At the time of notification of these cases the attention of the International Frequency Registration Board is drawn to the above condition.

(161) The standard frequency is 10,000 kc. (163) Between 12,925 and 13,200 kc the U. S. S. R. will meet their special requirements for the fixed service with due regard to technical provisions (power, location, antenna, etc.) with a view to minimizing the possibility of harmful interference with the maritime mobile service. Coast stations in the maritime mobile service will also have due regard to technical provisions (power, location, antenna, etc.), with a view to minimizing the possibility of harmful interference with the fixed service in the U. S. S. R. The International Frequency Registration Board will be consulted regarding these arrangements.

(164) The frequency 13,560 kc is designated for industrial, scientific and medical purposes. Emissions must be confined within the limits of +0.05% of this frequency. Radiocommunication services operating within these limits must accept any harmful interference that may be experienced from the operation of industrial, scientific and medical equipment.

(166) The standard frequency is 15,000 kc. (167) Between 17,160 and 17,360 kc, the U. S. S. R. will meet their special require

ments for the fixed service with due regard to technical provisions (power, location, antenna, etc.) with a view to minimizing the possibility of harmful interference with the maritime mobile service. Coast stations in

the maritime mobile service will also have due regard to technical provisions (power, location, antenna, etc.) with a view to minimizing the possibility of harmful interference with the fixed service in the U. S. S. R. The International Frequency Registration Board will be consulted regarding these arrangements.

(168) The standard frequency is 20,000 kc. (169) Inter-ship telegraphy in the maritime mobile service is permitted in the band 23,350-24,000 kc.

(170) The standard frequency is 25 Mc.

(171) The frequency 27.12 Mc is designated for industrial, scientific, and medical purposes. Emissions must be confined within the limits of ±0.6 percent of that frequency. Radiocommunication services operating within those limits must accept any harmful interference that may be experienced from the operation of industrial, scientific, and medical equipment.

(172) In Region 2, Australia, New Zealand, the Union of South Africa, and the territory under mandate of Southwest Africa, the amateur service will operate within the band 26.96-27.23 Mc.

(176) The frequency 40.68 Mc is designated for industrial, scientific and medical purposes. Emissions must be confined within the limits of +0.05% of that frequency. Radiocommunication services operating within those limits must accept any harmful interference that may be experienced from the operation of industrial, scientific and medical equipment.

(184) The frequency 75 Mc is designated for aeronautical marker beacons. In Region 1, the guard band is ±0.2 Mc; in Regions 2 and 3, ±0.4 Mc.

(195) The frequency 121.5 Mc is the aeronautical emergency frequency in this band.

(198) The frequency 156.80 Mc is designated for world-wide use for safety, calling and intership and harbor control communications in the maritime mobile service (simplex telephony). Any other use of this frequency should be avoided in areas where such other use is liable to cause harmful interference to the maritime mobile service. The interested administrations will ensure, by special arrangements where necessary, that an adequate guard band is provided. In Region 2, its use for this purpose will be restricted to the frequency modulated type of transmission (F3) and it is strongly recommended that the same type of transmission be adopted for this purpose in Regions 1 and 3.

ATLANTIC CITY FOOTNOTES- -continued

(208) The meteorological aids service (radiosonde) may be operated in the band 400-420 Mc.

(210) In the band 420-460 Mc the aeronautical radionavigation service has priority. The other services are admitted to this band only on condition that harmful interference is not caused to the aeronautical radionavigation service.

(211) In Region 2, the allocation for the aeronautical radionavigation service in the band 420-460 Mc is temporary and is exclusively for altimeters.

(212) In Region 2, the frequency 915 Mc is designated for industrial, scientific and medical purposes. Emissions must be confined within the limits of +25 Mc of that frequency. Radiocommunication services operating within those limits must accept any harmful interference that may be experienced from the operation of industrial, scientific and medical equipment.

(214) In Region 2, the fixed service may operate in the band 890-940 Mc.

(216) In Region 2, the band 1300-1660 Mc is intended for an integrated system of electronic aids to air navigation and traffic control. Administrations of the other Regions should envisage the possibility of the future application of such a system on a world-wide basis.

(218) In Region 2 and the United Kingdom, the use of the band 1300-1365 Mc is restricted to surveillance radar.

(220) In Region 2, Australia, New Zealand, Northern Rhodesia, Southern Rhodesia, the Union of South Africa, the territory under mandate of Southwest Africa, and the United Kingdom, the frequency 2450 Mc is designated for industrial, scientific and medical purposes. Emissions must be confined within the limits of 50 Mc of that frequency. Radiocommunication services operating within those limits must accept any harmful interference that may be experienced from the operation of industrial, scientific and medical equipment.

(222) The meteorological aids service may be operated in the band 2700-2900 Mc.

(223) The band 3246-3266 Mc is designated for racons.

(224) In the band 2900-3300 Mc shipborne radar in merchant ships is confined within the band 3000-3246 Mc.

(226) The band 5440-5460 Mc is designated for racons.

(227) In the band 5250-5650 Mc shipborne radar in merchant ships is confined within the band 5460-5650 Mc.

(228) In Region 2, Australia, New Zealand, Northern Rhodesia, Southern Rhodesia, the Union of South Africa, the territory under mandate of Southwest Africa,

and the United Kingdom the frequency 5850 Mc is designated for industrial, scientific and medical purposes. Emissions must be confined within the limits of +75 Mc of that frequency. Radiocommunication services operating within those limits must accept any harmful interference that may be experienced from the operation of industrial, scientific and medical equipment.

(230) The band 9300-9320 Mc is designated for racons.

(231) In the band 8500-9800 Mc shipborne radar in merchant ships is confined within the band 9320-9500 Mc.

(239) In certain cases, for which provision is made in articles 33 and 34 (of the Radio Regulations, Atlantic City, 1947), aircraft stations are authorized to use frequencies in the maritime mobile bands between 4000 and 23,000 kc for the purpose of entering into communication with stations of the maritime mobile service.

(256) Frequencies in any band allocated to the aeronautical mobile (R) service are reserved for communications between any aircraft and those aeronautical stations primarily concerned with the safety and regularity of flight along national or international civil air routes.

(259) The band 328.6-335.4 Mc is for the use of the Instrument Landing System (glide path).

(260) The band 4200-4400 Mc is for the use of radio altimeters.

(261) The band 5000-5250 Mc is for the use of instrument landing systems.

(269) In Region 2, the frequency band 2088.5-2093.5 kc is reserved exclusively for calling (telegraphy only).

(277) The frequency 8364 kc is designated for the use of survival craft equipped to transmit on frequencies between 4000 and 23,000 kc and wishing to establish, with stations of the maritime mobile service, communications relating to search and rescue.

NG FOOTNOTES

NG1 On the condition that harmful interference will not be caused to services operating in accordance with the table of frequency allocations, the following classes of stations may be authorized to use frequencies in this band: (1) Experimental stations engaged solely in scientific or technical radio experiments not related to an existing or proposed service nor intended to develop a proposed service or specific use of radio, (2) contract developmental stations, and (3) export developmental stations.

NG2 Emissions from industrial, scientific, and medical equipment using the frequency 27.12 Mc must be confined to the band 26.96-27.28 Mc.

NG3 Operational fixed stations may be authorized to use frequencies in this band