| Revision as of 02:10, 21 September 2020 editPengo (talk | contribs)Administrators19,328 edits Move United States-specific info out from the middle of a paragraph to its own paragraph← Previous edit | Revision as of 02:28, 21 September 2020 edit undoPengo (talk | contribs)Administrators19,328 edits add a list of types of Morse code radio transmissions (MCW and CW) discussed in this article, so reader doesn't have to reference another article for symbol meanings (Types of radio emissions)Next edit → | ||
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| '''Modulated continuous wave''' (MCW) is defined by the ] in 47 ] §97.3(c)(4) as "Tone-modulated international Morse code telegraphy emissions having designators with A, C, D, F, G, H or R as the first symbol; 2 as the second symbol; A or B as the third symbol." See ] for a general explanation of these symbols. Simply put, MCW uses an audio tone to modulate a ]. | '''Modulated continuous wave''' (MCW) is defined by the ] in 47 ] §97.3(c)(4) as "Tone-modulated international Morse code telegraphy emissions having designators with A, C, D, F, G, H or R as the first symbol; 2 as the second symbol; A or B as the third symbol." See ] for a general explanation of these symbols. Simply put, MCW uses an audio tone to modulate a ]. | ||
| Types of Morse code radio transmissions (MCW and CW) discussed in this article include: | |||
| * A1A and A2A — Double-sideband amplitude modulation (AM); One channel containing digital information, (1) no subcarrier or (2) using a subcarrier; Aural telegraphy (intended to be decoded by ear) | |||
| * F2A — Frequency modulation (FM); One channel containing digital information, using a subcarrier; Aural telegraphy | |||
| * J2A or J2B — ]; One channel containing digital information, using a subcarrier; (A) Aural telegraphy or (B) Electronic telegraphy | |||
| Unlike A1A CW transmissions, A2A MCW will produce an audible audio tone from an ] radio receiver that is not equipped with a beat oscillator. MCW is commonly used by ] ] to transmit the station identifier. | Unlike A1A CW transmissions, A2A MCW will produce an audible audio tone from an ] radio receiver that is not equipped with a beat oscillator. MCW is commonly used by ] ] to transmit the station identifier. | ||
Revision as of 02:28, 21 September 2020
| Passband modulation |
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| Analog modulation |
| Digital modulation |
| Hierarchical modulation |
| Spread spectrum |
| See also |
Modulated continuous wave (MCW) is defined by the Federal Communications Commission in 47 CFR §97.3(c)(4) as "Tone-modulated international Morse code telegraphy emissions having designators with A, C, D, F, G, H or R as the first symbol; 2 as the second symbol; A or B as the third symbol." See Types of radio emissions for a general explanation of these symbols. Simply put, MCW uses an audio tone to modulate a carrier wave.
Types of Morse code radio transmissions (MCW and CW) discussed in this article include:
- A1A and A2A — Double-sideband amplitude modulation (AM); One channel containing digital information, (1) no subcarrier or (2) using a subcarrier; Aural telegraphy (intended to be decoded by ear)
- F2A — Frequency modulation (FM); One channel containing digital information, using a subcarrier; Aural telegraphy
- J2A or J2B — Single-sideband with suppressed carrier; One channel containing digital information, using a subcarrier; (A) Aural telegraphy or (B) Electronic telegraphy
Unlike A1A CW transmissions, A2A MCW will produce an audible audio tone from an AM radio receiver that is not equipped with a beat oscillator. MCW is commonly used by RDF beacons to transmit the station identifier.
F2A MCW Morse can be heard on a normal FM radio receiver, and it is commonly used by both commercial and amateur repeater stations for identification. Also, F2A is sometimes used by other types of stations operating under automatic control, such as a telemetry transmitter or a remote base station.
MCW can be generated by any AM or FM radio transmitter with audio input from an audio oscillator or equivalent audio source. When an SSB transmitter is modulated by Morse code of only a single audio frequency, the resulting radio frequency emission is J2A or J2B and therefore is CW by definition, not MCW.
Within the United States, MCW transmission is not permitted to amateur radio operators in spectrum that is restricted to CW emission types only or CW, RTTY and data emission types only, or in the 60 meter band.
See also
References
- An MCW Keyer for V/UHR FM (N. Wilford, W1TLZ), QST April 2013, pp. 37-38
- PicoKeyer-Plus Kit
- U. S. Code of Federal Regulations, Title 47, Chapter 1, Subchapter D, Part 97.3(c)(1)
- U. S. Code of Federal Regulations, Title 47, Chapter 1, Subchapter D, Part 97.3(c)(5), 97.305(c), 97.307(f)(14)(i)
- "Amateur Radio Service Definitions (47 CFR §97.3)". Retrieved August 3, 2005.
- "Ham Radio Jargon, Abbreviations and Terminology". Archived from the original on September 19, 2017. Retrieved August 3, 2005.
| International Morse code | |
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| Transmission methods | |
| Notable signals | |
| Other writing systems in Morse code | |
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