Emission Designators

In radiocommunications we use emission designators to describe the characteristics of each radio emission. The full designation of an emission consists of NINE alpha-numeric characters, with the first 7 being mandatory. These nine symbols are divided into the ratio of 4:3:2 as follows;

  • The first FOUR symbols detail the necessary bandwidth, ranging from 0.001Hz to 999GHz.
  • The next THREE symbols detail the basic characteristics of the emission
  • The last TWO symbols are optional, and describe any additional characteristics



First FOUR Symbols

Specifies the bandwidth of the signal. Represented by three numerals and one letter (H = Hertz, K = kilohertz, M = Megahertiz, G = Gigahertz, with the letter taking the place of the decimal point (e.g. 10.0 kHz = 10K0). To help avoid confusion the first symbol can not be a zero (0) or a letter (K, M or G). Furthermore, the relevant bandwidth representation will be:

  • 0.001 Hz to 999 Hz: expressed as Hz (letter H)
  • 1.00 kHz to 999 kHz: expressed as kHz (letter K)
  • 1.00 MHz to 999 MHz: expressed as MHz (letter M)
  • 1.00 GHz to 999 GHz: expressed as GHz (letter G)

Next Three Symbols

FIRST Symbol - Defines the modulation of the main carrier
(a) Emission of an unmodulated carrier N
(b) Emission in which the main carrier is amplitude modulated (including cases where sub-carriers are angle modulated):
    (i) Double Sideband
    (ii) Single Sideband, full carrier
    (iii) Single sideband, reduced or variable carrier
    (iv) Single sideband, suppressed carrier
    (v) Independent sideband
    (vi) Vestigial sideband


A
H
R
J
B
C
(c) Emission in which the main carrier is angle modulated:
    (i) Frequency modulation
    (ii) Phase modulation

F
G
(d) Emission in which the main carrier is amplitude and angle modulated, either simultaneously or in a pre-established sequence D
(e) Emission of pulses:
    (i) Unmodulated sequence of pulses
    (ii) A sequence of pulses:
      (1) modulated in amplitude
      (2) modulated in width/duration
      (3) modulated in position/phase
      (4) in which the carrier is angle modulated during the period of the pulse
      (5) which is a combination of the foregoing or is produced by other means
P

K
L
M
Q
V
(f) Cases not covered above, in which an emission consists of the main carrier modulated, either simultaneously or in a pre-established sequence, in a combination of two or more of the following modes; amplitude, angle, pulse W
(g) Cases not otherwise covered X
SECOND Symbol - Nature of signal(s) modulating the carrier
(a) No modulating signal 0
(b) A single channel containing quantized or digital information without the use of a modulating sub-carrier 1
(c) A single channel containing quantized or digital information with the use of a modulating sub-carrier 2
(d) A single channel containing analogue information 3
(e) Two or more channels containing quantized or digital information 7
(f) Two or more channels containing analogue information 8
(g) Composite system with one or more channels containing quantized or digital information, together with one or more channels containing analogue information 9
(h) Cases not otherwise covered X
THIRD Symbol - Type of information to be transmitted
(a) No information transmitted N
(b) Telegraphy - for aural reception A
(c) Telegraphy - for automatic reception B
(d) Facsimile C
(e) Data transmission, telemtry, telecommand D
(f) Telephony (including sound broadcast) E
(g) Television (video) F
(h) Combination of the above W
(i) Cases not otherwise covered X

Last Two Symbols

These symbols are optional but are recommended when known. They help provide more details of the signal/emission.

FIRST symbol - Details of signal(s)
(a) Two-condition code with elements of differing number and/or durations A
(b) Two-condition code with elements of the same numbers and duration without error correction B
(c) Two-condition code with elements of the same numbers and duration with error correction C
(d) Four-condition code in which each condition represents a signal element (of one or more bits) D
(e) Multi-condition code in which each condition represents a signal element (of one or more bits) E
(f) Multi-condition code in which each condition or combination of condition represents a character F
(g) Sound of broadcasting quality (monophonic) G
(h) Sound of broadcasting quality (stereophonic or quadraphonic) H
(i) Sound of commercial quality (excluding categories given in sub-paragraphs (j) and (k) below) J
(j) Sound of commercial quality with the use of frequency inversion or bandsplitting K
(k) Sound of commercial quality with separate frequency modulated signals to control the level of demodulated signal L
(l) Monochrome M
(m) Colour N
(n) Combination of the above W
(o) Cases not otherwise covered X
SECOND symbol - Nature of multiplexing
(a) None N
(b) Code-division multiplex C
(c) Frequency-division multiplex F
(d) Time-division multiplex T
(e) Combination of frequency-division multiplex and time-division multiplex W
(f) Other types of multiplexing X

Putting it all together

Looking at all these symbols can be confusing, so here is a breakdown of some of the common designators:

10K1F3E (VHF/UHF FM voice)

  • 10K1 = 10.1kHz bandwidth
  • F = Frequency Modulation
  • 3 = Single channel containing analogue information
  • E = Telephony

3K00J3E (HF SSB voice)

  • 3K00 = 3.00kHz bandwidth
  • J = Single sideband suppressed carrier
  • 3 = Single channel containing analogue information
  • E = Telephony

200KF8EHF - FM Stereo Broadcast Radio

  • 200K = 200kHz bandwidth
  • F = Frequency Modulation
  • 8 = Two or more channels containing analogue information
  • E = Telephony
  • H = Sound of broadcasting quality (stereophonic or quadraphonic)
  • F = Frequency-division multiplexing