Misplaced Pages

This is an old revision of this page, as edited by 71.95.104.48 (talk) at 05:37, 30 January 2014 (modified mcw restriction text. Regulations state MCW is authorized above 50.1MHz except for 219-220 MHz. 144-144.1 MHz is CW only). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

Passband modulation
Analog modulation
AM FM PM QAM SM SSB
Digital modulation
ASK APSK CPM FSK MFSK MSK OOK PPM PSK QAM SC-FDE TCM TC-PAM WDM
Hierarchical modulation
QAM WDM
Spread spectrum
CSS DSSS FHSS THSS
See also
Capacity-approaching codes Demodulation Line coding Modem AnM PoM PAM PCM PDM PWM ΔΣM OFDM FDM Multiplexing
v t e

Modulated continuous wave 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. This is an older method of sending Morse code, with continuous wave being the more common method used today.

Unlike A1A CW transmissions, A2A MCW morse can clearly be heard on a normal AM radio receiver. It was commonly used by many RDF beacons to send a morse station identifier on a regular basis.

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. MCW is not allowed in the United States on amateur radio frequencies lower than 50.1 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 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.

See also

• Types of radio emissions

References

1. An MCW Keyer for V/UHR FM (N. Wilford, W1TLZ), QST April 20913, p37-38
2. PicoKeyer-Plus Kit http://www.hamgadgets.com/index.php?main_page=product_info&products_id=89
3. CW With Your H-T (Donald J. DuBon, N6JRL): http://www.af2cw.com/cw/CW%20With%20Your%20HT.pdf

• "Amateur Radio Service Definitions (47 CFR §97.3)". Retrieved August 3, 2005.

• "Ham Radio Jargon, Abbreviations and Terminology". Retrieved August 3, 2005.

This article related to amateur radio is a stub. You can help Misplaced Pages by expanding it.

• v
• t
• e

• Morse code
• Radio modulation modes
• Amateur radio stubs