Editing QRP operation (section)

=== Weak signal modes ===
QRP enthusiasts may use special modes that employ technology and software designed to enhance reception of the relatively weak transmitted signals resulting from low power levels.<ref name=WSM/>

'''QRSS''': Very slow speed Morse code 
:QRSS uses very slow speed [[continuous wave|CW]] (Morse code) to compensate for the decreased [[signal-to-noise ratio]] involved in QRP operation.<ref name=WSM/>{{efn|''QRSS'' is an exaggerated version of '''QRS''', the standard [[Q code]] used in radio communications. "'''QRS?'''" asks "''Shall I send more slowly?''".<ref name=Marchant>
{{cite book
 |last=Marchant |first=William Henry
 |year=1914
 |title=Wireless Telegraphy: A handbook for the use of operators and students
 |publisher=Whittaker
 |page=[https://archive.org/details/wirelesstelegra00marcgoog/page/n236 220]
 |url=https://archive.org/details/wirelesstelegra00marcgoog
 |via=Archive.org
}}
</ref>}} QRSS enthusiasts may record a transmission for later analysis, sometimes decoding "by ear" while playing it back at much faster speeds, or decoding "by eye" on the waterfall display of a spectrum analyzer.<ref name=DennisonFielding2007>
{{cite book
 |first1=Mike |last1=Dennison
 |first2=John |last2=Fielding
 |year=2007
 |title=Radio Communication Handbook
 |publisher=[[Radio Society of Great Britain]] (RSGB)
 |isbn=978-1-905086-33-7
 |url=https://books.google.com/books?id=f6AeAQAAIAAJ
 |via=Google Books
}}
</ref><ref>
{{cite web
 |title=Grabber compendium
 |department=QRSS Knights
 |website=digilander.libero.it
 |publisher=I2NDT
 |place=Bergamo, IT
 |url=http://digilander.libero.it/i2ndt/grabber/grabber-compendium.htm
}}
</ref>

'''Coherent CW''': Critically-timed Morse code transmission
:Coherent CW uses transmitters that clock-out signals calibrated to a precise rate, allowing receivers to employ extremely narrowband filtering to increase readability.<ref name=WSM/>

'''[[WSJT (amateur radio software)|WSJT]]''': Weak Signal – Joe Taylor
:WSJT is a software system that utilizes several separate modes, each optimized for a different signal path; these include [[Meteor burst communications|meteor scatter]], [[troposcatter]], and [[Earth–Moon–Earth communication|EME communications]]. WSJT was named after [[Joseph Hooton Taylor Jr.|Dr. J.H. Taylor]] to acknowledge his work in developing weak signal communication modes for radio.<ref name=WSM/>{{efn|Dr. [[Joseph Hooton Taylor Jr.]] is an astrophysicist who won the [[Nobel Prize in Physics]] in 1993 for discovery of a new type of [[pulsar]] which is useful for the study of [[General Relativity]] by [[radio astronomy]]. He is an [[amateur radio]] operator (currently K1JT), and has generously contributed his technical expertise to the development of successful transmission of weak signals over otherwise rarely usable propagation paths.}}

'''[[WSPR (amateur radio software)|WSPR]]''':  Weak Signal  –  Propagation Reporter
:WSPR is a software suite and computer network used to monitor propagation paths for optimal communication conditions.<ref name=WSM>
{{cite web
 |title=Weak signal modes
 |website=ARRL.org
 |publisher=[[American Radio Relay League]]
 |url=http://www.arrl.org/weak-signal-modes
 |access-date=24 November 2019
}}
</ref>