Bandwidth
The necessary bandwidth is expressed by three digits and a letter.
The letter occupies the position of the decimal point, representing the unity of bandwidth. This expression may not begin with zero nor K, M or G.
Between 0001 and 999 Hz shall be expressed in Hz (letter H) Between 1.00 and 999 kHz shall be expressed in kHz (letter K) Between 1.00 and 999 MHz shall be expressed in MHz (letter M) Between 1.00 and 999 GHz shall be expressed in GHz (letter G)
Examples:
100 Hz: 100H 2.7 KHz: 2K70 8.5 KHz: 8K50 16.0 KHz: 16K0 2.0 MHz: 2m00
Class:
Emissions are classified and symbolized according to their essential characteristics, and optionally with any additional features.
The essential features are:
* First symbol: type of modulation of main carrier • Second symbol - nature of the signal (or signals) that modulates (n) the main carrier · Third Symbol - type of information to be transmitted
Additional features for the classification of emissions
To describe more fully a particular issue should add two features that are optional. These additional optional features are:
• Fourth symbol - Details of the signal (or signals) · Fifth symbol - Nature of multiplexing or multiplexing.
When not using the fourth or the fifth symbol, it is indicated by a line in the place where each symbol had appeared.
1 - First Symbol type of modulation of the carrier, which is entered in Double Side Band. A Independent Side Band. B Residual Sideband. C Single Sideband and Complete Carrier. H Single Sideband and Suppressed Carrier. J Single Sideband and Reduced Carrier. R Unmodulated carrier. N Frequency Modulation. F Phase Modulation. G Amplitude and Angular modulated carrier. D Unmodulated pulses. P Amplitude modulated pulses. K Duration and pulse width modulated. L Phase and Position modulated pulses. M Angle Modulation with Carrier during the Pulse. Q Combining the preceding technique. V Cases not referred to combine two or more of the Modulation modes: Amplitude, Angular or impulses. W Cases not covered. X
2 - Second Symbol nature of the signal (or signals) that modulates the carrier No modulating signal. 0 Single Channel without the use of Digital Information Subcarrier Modulation. 1 Single Channel Using Digital Information Subcarrier Modulation. 2 Single Channel Analog Information. 3 Two or more channels of digital information. 7 Two or more channels of analog information. 8 Composed System Digital and Analog Information Channels. 9 Cases not covered. X
3 - Third Symbol Lack of Information. N Telegraph c / Acoustic Reception. A Telegraph c /Automatic Reception. B Fax. C Tx. Data, Telemetry and Remote Control. D Phone (including broadcasting). E Television (Video). F A combination of these. W Cases not covered. X
4 - Fourth Symbol - Signal Detail Two States Code with elements that differ in Number and / or duration. A Two States Code with identical elements in Number and / or duration without error correction. B Two States Code with identical elements in Number and / or duration, with error correction. C Four States Code, each one of which represents a signal element (of one or more bits). D Multiple States Code, each one of which represents a signal element (of one or more bits) E Multiple States Code, each one of which or a Combination of them represents a character. F Broadcasting Sound Quality (Mono). G Broadcastig Sound Quality (stereo or Quadraphonic). H Commercial Sound Quality (Excluding K and L). J Commercial Sound Quality with use of Phase Inversion and Band Division K Commercial Sound Quality Separate signals Frequency Modulated p / Signal Level Control Modulated. L Black and White signal. M Color signal. N Combination of the above. W Cases not covered. X
5 - Fifth Symbol - Nature of multiplexing No multiplexing. N Code division multiplexing for distribution. C Frequency division multiplexing for distribution. F Time division multiplexing. T Combination of multiplexing by Frequency Distribution, with Distribution in Time. W Other types. X
Examples:
100HA1AAN: Telegraphy in Morse code, 100 Hz bandwidth 10K0A3EGN: Telephony amplitude modulation, double sideband, 10.0 KHz bandwidth, broadcast-quality sound 2K70J3EJN: amplitude modulation telephony, single sideband with suppressed carrier, 2.7 KHz bandwidth, quality commercial sound 8K50F3EJN: Telephony modulation frequency, 8.5 kHz bandwidth, quality commercial sound 16K0G3EJN: Mobile phase modulation, 16.0 KHz bandwidth, quality commercial sound
Marcelino J. Garcia LU7DSU
Source: ITU and several articles on the web.
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