77 DUTCH EAST INDIAN STATEMENT CONCERNING TOPIC 14 OF THE PROGRAM ALLOCATION OF WAVES TO THE NATIONAL SERVICES It is suggested that a certain preference should be given, and that transmitters should be classified according to (a) Political interests (colonies, dominions). (b) Nature of traffic. 1. Telephony. 2. High-speed telegraphy. 3. Telephotography. 4. Telegraphy. 5. Traffic not open to public correspondence. 7. Experimental. (c) Amount of traffic. (d) Construction of transmitter and receiver. 1. Directional antenna. 2. Multiple. 3. Quartz. 4. Master oscillator. 5. Stabilizator. 6. Auto-oscillent. (e) Distance from corresponding station. (f) Difficulties to be overcome (difference between day and night, etc.). (g) Power of the transmitter. (h) Programs of traffic. 78 AUSTRIAN PROPOSAL CONCERNING TOPIC 7 OF THE PROGRAM WIDTH OF A FREQUENCY-BAND The use of Hertzian waves for different types of communication has so much increased during recent years that the question of inserting existing and proposed radio services without difficulty in the spectrum practicable for radio communication is a very serious problem. The main division of the spectrum among the different types of services, done at Washington, has already been exceeded in certain directions, since certain types of service in certain areas have increased in such a way that it was not possible for them to work without provisionally using bands reserved for other services. (See provisional distribution of waves for broadcasting in Europe arranged by the European Radio Conference at Prague, 1929.) The latest lists of frequencies published by the Berne Bureau show that the same difficulties which now exist as regards broadcasting in Europe will also arise in other types of service and in other areas, if not today, at any rate very shortly. Measures adopted hitherto to make the best use of the hertzianwave spectrum and to reduce or do away with the lack of waves were mainly in the way of organization and merely graduated the spectrum in a certain way and made general recommendations to prevent transmitting-stations from occupying too many frequencies in the spectrum. The recent session of the C. C. I. Radio had undertaken the task of bringing these recommendations into harmony with the present day state of the art. In view of the radical proposals of certain delegations it may be expected that the question of economic wave distribution will make considerable progress during the present conference. It is therefore easy to see that the best use of the hertzian-wave spectrum can only be made, if the arrangement for carrying out radio-transmissions are such that the frequency-band necessary for any radio-transmission, calculated solely on the basis of physical principles, should in practice be overlapped as little as possible. In this connection, it must be noted that most transmitters (except a very small number) at present generally transmit a carrier wave and further two side frequency-bands. Many types of radio-transmissions, from the physical point of view, would do their work practically just as satisfactorily by using only one side-band or one side-band and the carrier wave. It is true that inconveniences may arise in carrying out such radio-transmissions in practice (e. g., more complicated construction and restricted efficacy of transmitters, a certain distortion at the receiver end); these inconveniences may be possibly reduced by appropriate measures. But on the other side, there is the great advantage of a considerable economy in the width of the frequencyband necessary for a radio-transmission. This advantage would be very important in transmissions which require a wide frequencyband (speech, music, pictures, multiplex, etc.). The bands thus economized might be used to improve the conditions of transmission, in so far as they depend on the frequency distance between neighboring stations (e. g., increase of frequency distance for European broadcasting stations from 9 kc/s to 10 kc/s or more) or to enable new transmitters to be established and so 77 DUTCH EAST INDIAN STATEMENT CONCERNING TOPIC 14 OF THE PROGRAM ALLOCATION OF WAVES TO THE NATIONAL SERVICES It is suggested that a certain preference should be given, and that transmitters should be classified according to (a) Political interests (colonies, dominions). (b) Nature of traffic. 1. Telephony. 2. High-speed telegraphy. 3. Telephotography. 4. Telegraphy. 5. Traffic not open to public correspondence. 7. Experimental. (c) Amount of traffic. (d) Construction of transmitter and receiver. 1. Directional antenna. 2. Multiple. 3. Quartz. 4. Master oscillator. 5. Stabilizator. 6. Auto-oscillent. (e) Distance from corresponding station. (f) Difficulties to be overcome (difference between day and night, etc.). (g) Power of the transmitter. (h) Programs of traffic. 78 AUSTRIAN PROPOSAL CONCERNING TOPIC 7 OF THE PROGRAM WIDTH OF A FREQUENCY-BAND The use of Hertzian waves for different types of communication has so much increased during recent years that the question of inserting existing and proposed radio services without difficulty in the spectrum practicable for radio communication is a very serious problem. The main division of the spectrum among the different types of services, done at Washington, has already been exceeded in certain directions, since certain types of service in certain areas have increased in such a way that it was not possible for them to work without provisionally using bands reserved for other services. (See provisional distribution of waves for broadcasting in Europe arranged by the European Radio Conference at Prague, 1929.) The latest lists of frequencies published by the Berne Bureau show that the same difficulties which now exist as regards broadcasting in Europe will also arise in other types of service and in other areas, if not today, at any rate very shortly. Measures adopted hitherto to make the best use of the hertzianwave spectrum and to reduce or do away with the lack of waves were mainly in the way of organization and merely graduated the spectrum in a certain way and made general recommendations to prevent transmitting-stations from occupying too many frequencies in the spectrum. The recent session of the C. C. I. Radio had undertaken the task of bringing these recommendations into harmony with the present day state of the art. In view of the radical proposals of certain delegations it may be expected that the question of economic wave distribution will make considerable progress during the present conference. It is therefore easy to see that the best use of the hertzian-wave spectrum can only be made, if the arrangement for carrying out radio-transmissions are such that the frequency-band necessary for any radio-transmission, calculated solely on the basis of physical principles, should in practice be overlapped as little as possible. In this connection, it must be noted that most transmitters (except a very small number) at present generally transmit a carrier wave and further two side frequency-bands. Many types of radio-transmissions, from the physical point of view, would do their work practically just as satisfactorily by using only one side-band or one side-band and the carrier wave. It is true that inconveniences may arise in carrying out such radio-transmissions in practice (e. g., more complicated construction and restricted efficacy of transmitters, a certain distortion at the receiver end); these inconveniences may be possibly reduced by appropriate measures. But on the other side, there is the great advantage of a considerable economy in the width of the frequencyband necessary for a radio-transmission. This advantage would be very important in transmissions which require a wide frequencyband (speech, music, pictures, multiplex, etc.). The bands thus economized might be used to improve the conditions of transmission, in so far as they depend on the frequency distance between neighboring stations (e. g., increase of frequency distance for European broadcasting stations from 9 kc/s to 10 kc/s or more) or to enable new transmitters to be established and so |