Emission Designators

An emission designator utilizes a seven-character “word” to represent the bandwidth, modulation, nature of signal, and type of information transmitted by a particular radio. The emission designator is required in most FCC radio applications. An emission designator consists of seven characters as follows:

· The first four characters identify the necessary bandwidth required to transmit the desired information at the rate and with the quality required for the system employed;
· The fifth character identifies the type of modulation of the main carrier;
· The sixth character identifies the nature of signal(s) modulating the main carrier;
· The seventh character identifies the type of information to be transmitted.

Detailed information and examples of each of the four components are provided below. Necessary Bandwidth – First Four Characters The necessary bandwidth is to be expressed using three numerals and one letter. The letter occupies the position of the decimal point and represents the unit of bandwidth. The first character can be neither zero, K, M, nor G; it must be a non-zero digit or H. The necessary bandwidths must be rounded to three significant digits. The rounded value of the necessary bandwidth must follow the syntax below:

· between 0.00100 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:

Guide to Emission Designators (continued). Types of Modulation of the Main Carrier – Fifth Character.

NOTE: Whenever frequency modulation "F" is indicated, Phase modulation "G" is also acceptable. Emissions where the main carrier is directly modulated by a signal which has been coded into quantized form (e.g. pulse code modulation) should be designated under amplitude modulation or angle modulation.

Nature of Signal(s) Modulating the Main Carrier – Sixth Character


Type of Information to be Transmitted – Seventh Character