Amateur Emission Designations

Classification of Emissions.

Emission classifications provide an internationally recognised standard in which to specify accurately and concisely, the significant characteristics of a transmission.

Classification Method

A total of nine letters & figures are used. The first four give details of the bandwidth needed, the next three are the basic characteristics of the emission and the last two (optional) give any extra details which might be needed to further describe the emission.

Example:

6M25 C3F MN

6.25 MHz bandwidth vestigial sideband single channel analogue television monochrome signal with no multiplexing.

Following is a listing of emission types that maybe found in Amateur Radio

First Four Symbols

These give details of the bandwidth using three digits & one letter, with the letter providing the position of the decimal point. The letters used are H for Hertz, K for Kilohertz, M for Megahertz and G for Gigahertz.

Example: 6M25 (6.25MHz)

Next Three Symbols

The first defines the type of modulation of the main carrier. The next describes the nature of the signal modulating the carrier and the third describes the type of information being transmitted.

• First Symbol- type of modulation of the main carrier

  1. Emission in which the main carrier is amplitude modulated:

     Double sideband (amplitude modulated)	A
     Single sideband, full carrier	H
     Single sideband, reduced carrier	R
     Single sideband, Suppressed carrier	J
     Independent sideband	B
     Vestigial sideband	C

  2. Emissions in which the main carrier is angle modulated:

     Frequency modulation	F
     Phase modulation	G

  3. Emission of pulses:

     Unmodulated sequence of pulses

     P

• Second Symbol - nature of the signal(s) modulating the main carrier.

  1. No modulating signal	0
     A single channel containing quantitised or digital information without the use of a modulating sub-carrier	1
     A single channel containing quantitised or digital information with the use of a modulating sub-carrier	2
     A single channel containing analogue information	3
     Two or more channels containing analogue information	8

• Third Symbol - type of information being transmitted.

  1. No information being transmitted	N
     Telegraphy - for aural reception	A
     Telegraphy for automatic reception	B
     Facsimile	C
     Data transmission, telemetry, telecommand	D
     Telephony	E
     Television	F
     Combination of the above	W

Last Two Symbols (Optional)

• First Symbol - details of signal
  1. .

     Sound of commercial quality with the use of frequency inversion or bandsplitting	K
     Monochrome	M
     Colour	N

• Second Symbol -nature of multiplexing
  1.  

     None

     N