MODULATION CODES

For Definitions of the First, Second and Third Characters -- SEE:
Classification of Emissions -- From The ITU
Do a search for "Appendix S1 - Designation of emissions"

Classification of emissions -- From The FCC -- The Code of Federal Regulations

Radio emissions are defined with an alphamumeric code, for example:

A1A is an ON/OFF keyed carrier (as in "CW" "Morse")
A3E is double-sideband with full carrier ("AM", "broadcast")
J3E is single-sideband ("SSB") suppressed carrier
F3E is frequency modulation telephony;
F2D: frequency shift keyed audio tone, data packet. Packet Radio.

A1A -telegraphy (on - off keying) without modulation by an audio frequency;

A1B - amplitude modulation telegraphy with automatic reception, without using a modulating subcarrier;

A1D -amplitude modulation data transmission, double sideband, without using a modulating subcarrier;

A2A -on-off keying telegraphy using one or several modulating audio frequencies, or on-off keying telegraphy of an amplitude modulated emission;

A2B -amplitude modulation telegraphy with automatic reception and using on-off keying of the modulating subcarrier;

A2D -amplitude modulation data transmission, double sideband and using a modulating subcarrier;

A3C -amplitude modulation facsimile; the main carrier is modulated either directly or by a frequency modulated subcarrier;

A3E -amplitude modulation telephony, double sideband;

C3F -television, in amplitude modulation, with vestigial sideband;

F1A - telegraphy (keyed by frequency variation);

F1B -frequency modulation telegraphy with automatic reception, without using a modulating subcarrier;

F1D -frequency modulation data transmission, double sideband, without using a modulating subcarrier;

F2A - on-off keying telegraphy of an audio frequency for frequency modulation, or by on-off keying of a frequency modulated emission (special case: unkeyed frequency modulated emission);

F2B -frequency modulation telegraphy with automatic reception and using on-off keying of the modulating subcarrier;

F2D -frequency modulation data transmission, using a modulating subcarrier;

F3C - modulation frequency facsimile, by direct modulation of carrier frequency;

F3E - frequency modulation telephony;

F3F - television with frequency modulation;

G1D -phase modulation data transmission, without using a modulating subcarrier;

G2D -phase modulation data transmission, using a modulating subcarrier;

G3C -phase modulation facsimile:

G3E -phase modulation telephony;

G3F -television in phase modulation;

J1D -amplitude modulation data transmission, single sideband, suppressed carrier, using a modulating subcarrier;

J2A -on-off keying telegraphy using one or several modulating audio frequencies, or an on-off keying telegraphy, single sideband, with suppressed carrier;

J2D -amplitude modulation data transmission, single sideband, suppressed carrier without using a modulating subcarrier;

J3C - amplitude modulation facsimile; single sideband, with suppressed carrier;

J3E -amplitude modulation telephony, single sideband, with suppressed carrier;

J8E -amplitude modulation telephony, independent sidebands;

K1A -on-off keying telegraphy of a carrier transmitted by pulses, without modulation by an audio frequency;

K2A -on-off keying telegraphy of one or several audio modulating frequencies, or by on-off keying of a modulated carrier transmitted by pulses (special case: unkeyed modulated carrier transmitted by pulses);

K3E - pulse modulation telephony.

R3C - amplitude modulation facsimile; single sideband, with vestigial carrier;

R3D -amplitude modulation data transmission, single sideband, with vestigial carrier;

R3E -amplitude modulation telephony, single sideband, with vestigial carrier;

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