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| {{Modulation techniques}} | {{Modulation techniques}} | ||
| '''Modulated continuous wave''' 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. | '''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 a fixed audio tone to modulate a ]. | ||
| 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. | |||
| Simply put, MCW uses a fixed audio tone to modulate a ]. This is an older method of sending ], with ] being the more common method used today. | |||
| F2A MCW Morse can be heard on a normal ] radio receiver, and it is commonly used by both commercial and amateur ] stations for ]. Also, F2A is sometimes used by other types of stations operating under automatic control, such as a ] transmitter or a ]. | |||
| MCW can be generated by any AM or FM radio transmitter with audio input from an audio oscillator or equivalent audio source.<ref>An MCW Keyer for V/UHR FM (N. Wilford, W1TLZ), QST April 2013, pp. 37-38</ref><ref></ref> MCW transmission is not permitted to ] operators within the United States in spectrum that is restricted to CW emission types only or RTTY and data emission types only, or in the 60 meter band.<ref></ref> 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.<ref></ref> | |||
| MCW can be transmitted from any common amateur radio transceiver in AM or FM mode with audio input from an audio tone oscillator or equivalent audio source.<ref>An MCW Keyer for V/UHR FM (N. Wilford, W1TLZ), QST April 20913, p37-38</ref><ref>PicoKeyer-Plus Kit http://www.hamgadgets.com/index.php?main_page=product_info&products_id=89</ref><ref>CW With Your H-T (Donald J. DuBon, N6JRL): http://www.af2cw.com/cw/CW%20With%20Your%20HT.pdf</ref> MCW is not allowed in the United States on ] frequencies lower than ], between 144.0 and 144.1 MHz, or between 219 and 220 MHz, as it is a very inefficient use of radio spectrum. When the amateur radio transceiver is in SSB mode, the resulting modulation is J2A or J2B and therefore not MCW by definition. | |||
| F2A MCW morse can be heard on a normal ] radio receiver, and it is commonly used by both commercial and amateur ] stations for ]. Also, F2A is sometimes used by other types of stations operating under automatic control, such as a ] transmitter or a ]. | |||
| == See also == | == See also == | ||
Revision as of 21:04, 11 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 a fixed audio tone to modulate a carrier wave.
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. MCW transmission is not permitted to amateur radio operators within the United States in spectrum that is restricted to CW emission types only or RTTY and data emission types only, or in the 60 meter band. 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.
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)(5), 97.305(c), 97.307(f)(14)(i)
- U. S. Code of Federal Regulations, Title 47, Chapter 1, Subchapter D, Part 97.3(c)(1)
- "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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