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QRP operation
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<h2 id="etymology">Etymology</h2> <p>The term "QRP" derives from the standard <a href="/facts/Q_code/vCojlUkH">Q code</a> used in radio communication, where QRP is used to request "<i>Reduce power</i>" and QRP? is used to ask "<i>Should I reduce power?</i>".<a class="footnote-ref" id="fnref:2" href="#fn:2"><sup>2</sup></a><a class="footnote-ref" id="fnref:3" href="#fn:3"><sup>3</sup></a> </p> <h2 id="philosophy">Philosophy</h2> <p>Most amateur transceivers are capable of transmitting approximately 100 watts,<a class="footnote-ref" id="fnref:4" href="#fn:4"><sup>4</sup></a> but in some parts of the world, such as the U.S., amateurs can transmit up to 1,500 watts. QRP enthusiasts contend that this practice is rarely necessary, and doing so wastes power, increases the likelihood of causing <a href="/facts/Electromagnetic_interference/gv3DlKNr">interference</a> to nearby <a href="/facts/Television/X4YG5nT1">televisions</a>, <a href="/facts/Receiver_(radio)/5olDTxkg">radios</a>, and <a href="/facts/Telephone/P7uEgWQX">telephones</a> and, for <a href="/facts/United_States/P0sCdLe5">United States</a>' amateurs, is contrary to <a href="/facts/Federal_Communications_Commission/Ueghz8W0">FCC</a> Part 97 rule, which states that one must use "the minimum power necessary to carry out the desired communications".<a class="footnote-ref" id="fnref:5" href="#fn:5"><sup>5</sup></a> QRP can also be used for <a href="/facts/Amateur_radio_emergency_communications/I6hXocef">emergency communications</a> during <a href="/facts/Emergency_management/YjGIyW91">disaster recovery</a>, when frugal use of available battery power and generator fuel is crucial.<a class="footnote-ref" id="fnref:6" href="#fn:6"><sup>6</sup></a><a class="footnote-ref" id="fnref:7" href="#fn:7"><sup>7</sup></a><a class="footnote-ref" id="fnref:8" href="#fn:8"><sup>8</sup></a> </p> <h2 id="practice">Practice</h2> <p>The practice of operating with low power was popularized as early as 1924, with a variety of reports, editorials and articles published in U.S. amateur radio magazines and journals that encouraged amateurs to lower power output, both for purposes of experimentation, and for improving operating conditions by reducing interference.<a class="footnote-ref" id="fnref:9" href="#fn:9"><sup>9</sup></a> </p><p>Although not universally agreed upon, the ARRL makes a recommendation for QRP power limits. Most amateur organizations agree that for <a href="/facts/Morse_code/GXwCl1HV">CW</a>, <a href="/facts/Amplitude_modulation/3sTxsXk6">AM</a>, <a href="/facts/Frequency_modulation/qIExDdtv">FM</a>, and <a href="/facts/Data/AUBFN97o">data</a> <a href="/facts/Modulation/aAXPjINv">modes</a>, the <a href="/facts/Transmitter/nFYghtKv">transmitter</a> <a href="/facts/Transmitter_power_output/8WvTscAX">output power</a> should be 5 <a href="/facts/Watt/VK8oqRrm">watts</a> (or less).<a class="footnote-ref" id="fnref:10" href="#fn:10"><sup>10</sup></a> The maximum output power for <a href="/facts/Single-sideband_modulation/Cfuv9KX1">SSB</a> (single sideband) is sometimes agreed to be no more than 10 Watts <a href="/facts/Peak_envelope_power/2j6eS46U">peak envelope power</a> (PEP), while some organisations opine that the power limit should be 5 Watts. QRPers are known to regularly use less than 5 Watts, sometimes operating with as little as 100 milliwatts or even less. Extremely low power — 1 Watt and below — is often referred to by hobbyists as "QRPP".<a class="footnote-ref" id="fnref:11" href="#fn:11"><sup>11</sup></a><a class="footnote-ref" id="fnref:12" href="#fn:12"><sup>12</sup></a><a class="footnote-ref" id="fnref:13" href="#fn:13"><sup>13</sup></a><a class="footnote-ref" id="fnref:14" href="#fn:14"><sup>14</sup></a> </p><p>Communicating using QRP can be difficult since the QRPer must face the same challenges of <a href="/facts/Radio_propagation/80y1JV4M">radio propagation</a> faced by amateurs using higher power levels, but with the inherent disadvantages associated with having a weaker signal on the receiving end, all other things being equal. QRP aficionados try to make up for this through more efficient <a href="/facts/Antenna_(radio)/pGlcXBvc">antenna</a> systems and enhanced operating skills.<a class="footnote-ref" id="fnref:15" href="#fn:15"><sup>15</sup></a><a class="footnote-ref" id="fnref:16" href="#fn:16"><sup>16</sup></a> </p> <h3>Weak signal modes</h3> <p>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.<a class="footnote-ref" id="fnref:17" href="#fn:17"><sup>17</sup></a> </p><p>QRSS: Very slow speed Morse code </p> QRSS uses very slow speed <a href="/facts/Continuous_wave/XdKlBpgP">CW</a> (Morse code) to compensate for the decreased <a href="/facts/Signal-to-noise_ratio/qohClhyG">signal-to-noise ratio</a> involved in QRP operation.<a class="footnote-ref" id="fnref:18" href="#fn:18"><sup>18</sup></a><a class="footnote-ref" id="fnref:19" href="#fn:19"><sup>19</sup></a> 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.<a class="footnote-ref" id="fnref:20" href="#fn:20"><sup>20</sup></a><a class="footnote-ref" id="fnref:21" href="#fn:21"><sup>21</sup></a> <p>Coherent CW: Critically-timed Morse code transmission </p> Coherent CW uses transmitters that clock-out signals calibrated to a precise rate, allowing receivers to employ extremely narrowband filtering to increase readability.<a class="footnote-ref" id="fnref:22" href="#fn:22"><sup>22</sup></a> <p><a href="/facts/WSJT_(amateur_radio_software)/CXpMfGto">WSJT</a>: Weak Signal – Joe Taylor </p> WSJT is a software system that utilizes several separate modes, each optimized for a different signal path; these include <a href="/facts/Meteor_burst_communications/nR3IQtPV">meteor scatter</a>, <a href="/facts/Troposcatter/8yCB9H5B">troposcatter</a>, and <a href="/facts/Earth%E2%80%93Moon%E2%80%93Earth_communication/cwU8v8Xx">EME communications</a>. WSJT was named after <a href="/facts/Joseph_Hooton_Taylor_Jr./Dn44wNWD">Dr. J.H. Taylor</a> to acknowledge his work in developing weak signal communication modes for radio.<a class="footnote-ref" id="fnref:23" href="#fn:23"><sup>23</sup></a><a class="footnote-ref" id="fnref:24" href="#fn:24"><sup>24</sup></a> <p><a href="/facts/WSPR_(amateur_radio_software)/RgffmzyP">WSPR</a>: Weak Signal – Propagation Reporter </p> WSPR is a software suite and computer network used to monitor propagation paths for optimal communication conditions.<a class="footnote-ref" id="fnref:25" href="#fn:25"><sup>25</sup></a> <h2 id="equipment">Equipment</h2> <p>Many of the larger, more powerful commercial transceivers permit the operator to lower their output level to QRP levels. Commercial <a href="/facts/Two-way_radio/e6JKFtdo">transceivers</a> specially designed to operate at or near QRP power levels have been commercially available since the late 1960s. </p><p>In 1969 the American manufacturer Ten-Tec produced the Powermite-1, one of Ten-Tec's first assembled transceivers, and featured modular construction. All stages of the transceiver were on individual <a href="/facts/Printed_circuit_board/muSR2p43">circuit boards</a>: the transmitter was capable of about one or two watts of RF, and the receiver was a <a href="/facts/Direct-conversion_receiver/flQEkvm6">direct-conversion</a> unit, similar to that found in the <a href="/facts/Heathkit/UzElPd6X">Heathkit</a> HW-7 and HW-8 lines, which introduced many amateurs to QRP'ing and led to the popularity of the mode.<a class="footnote-ref" id="fnref:26" href="#fn:26"><sup>26</sup></a> </p><p>Enthusiasts operate QRP radios on the <a href="/facts/High_frequency/JmDJLR5I">HF</a> <a href="/facts/Band_(radio)/AP2frA1C">bands</a> in <a href="/facts/Amateur_radio_station/vo4Fbkk3">portable modes</a>, usually carrying the radios in <a href="/facts/Backpack/uvI4lVWl">backpacks</a>, with <a href="/facts/Whip_antenna/ogld3BuQ">whip antennas</a>. Some QRPers prefer to construct their equipment from kits, published plans,<a class="footnote-ref" id="fnref:27" href="#fn:27"><sup>27</sup></a> or <a href="/facts/Amateur_radio_homebrew/9fGQTwHB">homebrew</a> it from scratch. Many popular designs are based on the <a href="/facts/NE612/w6cLWScg">NE612</a> mixer IC, i.e. the K1, K2, ATS series and the Softrock SDR.<a class="footnote-ref" id="fnref:28" href="#fn:28"><sup>28</sup></a> </p> <h2 id="organizations">Organizations</h2> <p>Amateur radio organizations dedicated to QRP include QRP Amateur Radio Club International (QRPARCI), American QRP Club, G-QRP Club based in the <a href="/facts/United_Kingdom/kuPAILt2">United Kingdom</a>, and The Adventure Radio Society emphasizing portable QRP operation. Major QRP gatherings are held yearly at <a href="/facts/Hamfest/d1aSls5D">hamfests</a> such as <a href="/facts/Dayton_Hamvention/cYy0V8Nd">Dayton Hamvention</a>, Pacificon, and <a href="/facts/Friedrichshafen/l6W8Jojh">Friedrichshafen</a>.<a class="footnote-ref" id="fnref:29" href="#fn:29"><sup>29</sup></a> </p> <h2 id="contests-and-awards">Contests and awards</h2> <p>There are specific operating <a href="/facts/Award/rII9lQH2">awards</a>, <a href="/facts/Contesting/s0JvzJby">contests</a>, <a href="/facts/Club_(organization)/8vmeaRQs">clubs</a>, and <a href="/facts/Convention_(meeting)/FUaCMsLS">conventions</a> devoted to QRP enthusiasts. In the United States, the November Sweepstakes, June and September VHF QSO Parties, January VHF Sweepstakes, and the <a href="/facts/American_Radio_Relay_League/NXFGqIPA">ARRL</a> International DX Contest, as well as many major international contests have designated special QRP categories. For example, during the annual ARRL's <a href="/facts/Field_Day_(amateur_radio)/8NSBDPEE">Field Day</a> event, making a QSO (ham-to-ham contact) using "QRP battery power" is worth five times as many points as a contact made by conventional means. The QRP ARCI club sponsors 12 contests during the year specifically for QRP operators.<a class="footnote-ref" id="fnref:30" href="#fn:30"><sup>30</sup></a><a class="footnote-ref" id="fnref:31" href="#fn:31"><sup>31</sup></a> </p><p>Typical awards include the QRP ARCI club's "thousand-miles-per-watt" award, available to anyone presenting evidence of a qualifying contact. QRP ARCI also offers special awards for achieving the ARRL's <a href="/facts/Worked_All_States/leJnBS6G">Worked All States</a>, <a href="/facts/Worked_All_Continents/leJnBS6G">Worked All Continents</a>, and <a href="/facts/DX_Century_Club/leJnBS6G">DX Century Club</a> awards under QRP conditions. Other QRP clubs also offer similar versions of these awards, as well as general QRP operating achievement awards.<a class="footnote-ref" id="fnref:32" href="#fn:32"><sup>32</sup></a> </p> <h2 id="see-also">See also</h2> <ul><li><a href="/facts/Amateur_radio_homebrew/9fGQTwHB">Amateur radio homebrew</a></li> <li><a href="/facts/List_of_amateur_radio_transceivers/cyljcq7D">List of amateur radio QRP transceivers</a></li></ul> <h2 id="notes">Notes</h2> <h2 id="references">References</h2> <ol> <li id="fn:1"><p>"Why QRP?". arrl.org. American Radio Relay League. Retrieved 10 December 2019. <a href="http://www.arrl.org/why-qrp" target="_blank">http://www.arrl.org/why-qrp</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li> <li id="fn:2"><p>Marchant, William Henry (1914). Wireless Telegraphy: A handbook for the use of operators and students. Whittaker. p. 220 – via Archive.org. <a href="https://archive.org/details/wirelesstelegra00marcgoog" target="_blank">https://archive.org/details/wirelesstelegra00marcgoog</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li> <li id="fn:3"><p>The opposite of QRP is QRO, or increased power operation.[2] <a href="/wiki/QRO" target="_blank">/wiki/QRO</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li> <li id="fn:4"><p>The ARRL General Class License Manual. American Radio Relay League. 1998. pp. 3. ISBN 978-0-87259-676-4 – via Archive.org. The maximum power output from most amateur transceivers is about 100 W. <a href="978-0-87259-676-4" target="_blank">978-0-87259-676-4</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></p></li> <li id="fn:5"><p>Wells, Bradley (April 1984). "QRP: More than a state of mind". QST Magazine. Newington, CT: American Radio Relay League. p. 52. Retrieved 24 November 2019. <a href="http://www.arrl.org/qrp-more-than-a-state-of-mind" target="_blank">http://www.arrl.org/qrp-more-than-a-state-of-mind</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></p></li> <li id="fn:6"><p>Arland, Richard H. (2007). ARRL's Low Power Communication: The art and science of QRP. American Radio Relay League. ISBN 978-0-87259-104-2 – via Google Books. <a href="978-0-87259-104-2" target="_blank">978-0-87259-104-2</a> <a href="#fnref:6" class="footnote-back-ref">↩</a></p></li> <li id="fn:7"><p>Dobbs, George (1 September 2012). QRP Basics. Radio Society of Great Britain (RSGB). ISBN 978-1-905086-84-9 – via Google Books. <a href="978-1-905086-84-9" target="_blank">978-1-905086-84-9</a> <a href="#fnref:7" class="footnote-back-ref">↩</a></p></li> <li id="fn:8"><p>H. Ward Silver (25 February 2011). Ham Radio For Dummies. John Wiley & Sons. p. 218. ISBN 978-1-118-05419-2 – via Google Books. <a href="978-1-118-05419-2" target="_blank">978-1-118-05419-2</a> <a href="#fnref:8" class="footnote-back-ref">↩</a></p></li> <li id="fn:9"><p>Weiss, Adrian (1987). History of QRP in the U.S., 1924-1960. Vermillion, SD: Milliwatt Books. ISBN 978-0-9614139-1-0. OL 2411449M. <a href="978-0-9614139-1-0" target="_blank">978-0-9614139-1-0</a> <a href="#fnref:9" class="footnote-back-ref">↩</a></p></li> <li id="fn:10"><p>Rutledge, David (1999). The Electronics of Radio. Cambridge University Press. p. 312. ISBN 978-1-107-39366-0 – via Google Books. <a href="978-1-107-39366-0" target="_blank">978-1-107-39366-0</a> <a href="#fnref:10" class="footnote-back-ref">↩</a></p></li> <li id="fn:11"><p>Wells, Bradley (April 1984). "QRP: More than a state of mind". QST Magazine. Newington, CT: American Radio Relay League. p. 52. Retrieved 24 November 2019. <a href="http://www.arrl.org/qrp-more-than-a-state-of-mind" target="_blank">http://www.arrl.org/qrp-more-than-a-state-of-mind</a> <a href="#fnref:11" class="footnote-back-ref">↩</a></p></li> <li id="fn:12"><p>Arland, Richard H. (2007). ARRL's Low Power Communication: The art and science of QRP. American Radio Relay League. ISBN 978-0-87259-104-2 – via Google Books. <a href="978-0-87259-104-2" target="_blank">978-0-87259-104-2</a> <a href="#fnref:12" class="footnote-back-ref">↩</a></p></li> <li id="fn:13"><p>Dobbs, George (1 September 2012). QRP Basics. Radio Society of Great Britain (RSGB). ISBN 978-1-905086-84-9 – via Google Books. <a href="978-1-905086-84-9" target="_blank">978-1-905086-84-9</a> <a href="#fnref:13" class="footnote-back-ref">↩</a></p></li> <li id="fn:14"><p>DeMaw, Doug (1991). W1FB's QRP Notebook. American Radio Relay League. ISBN 978-0-87259-365-7 – via Google Books. <a href="978-0-87259-365-7" target="_blank">978-0-87259-365-7</a> <a href="#fnref:14" class="footnote-back-ref">↩</a></p></li> <li id="fn:15"><p>DeMaw, Doug (1991). W1FB's QRP Notebook. American Radio Relay League. ISBN 978-0-87259-365-7 – via Google Books. <a href="978-0-87259-365-7" target="_blank">978-0-87259-365-7</a> <a href="#fnref:15" class="footnote-back-ref">↩</a></p></li> <li id="fn:16"><p>H. Ward Silver (25 February 2011). Ham Radio For Dummies. John Wiley & Sons. p. 218. ISBN 978-1-118-05419-2 – via Google Books. <a href="978-1-118-05419-2" target="_blank">978-1-118-05419-2</a> <a href="#fnref:16" class="footnote-back-ref">↩</a></p></li> <li id="fn:17"><p>"Weak signal modes". ARRL.org. American Radio Relay League. Retrieved 24 November 2019. <a href="http://www.arrl.org/weak-signal-modes" target="_blank">http://www.arrl.org/weak-signal-modes</a> <a href="#fnref:17" class="footnote-back-ref">↩</a></p></li> <li id="fn:18"><p>"Weak signal modes". ARRL.org. American Radio Relay League. Retrieved 24 November 2019. <a href="http://www.arrl.org/weak-signal-modes" target="_blank">http://www.arrl.org/weak-signal-modes</a> <a href="#fnref:18" class="footnote-back-ref">↩</a></p></li> <li id="fn:19"><p>QRSS is an exaggerated version of QRS, the standard Q code used in radio communications. "QRS?" asks "Shall I send more slowly?".[2] <a href="/wiki/Q_code" target="_blank">/wiki/Q_code</a> <a href="#fnref:19" class="footnote-back-ref">↩</a></p></li> <li id="fn:20"><p>Dennison, Mike; Fielding, John (2007). Radio Communication Handbook. Radio Society of Great Britain (RSGB). ISBN 978-1-905086-33-7 – via Google Books. <a href="978-1-905086-33-7" target="_blank">978-1-905086-33-7</a> <a href="#fnref:20" class="footnote-back-ref">↩</a></p></li> <li id="fn:21"><p>"Grabber compendium". QRSS Knights. digilander.libero.it. Bergamo, IT: I2NDT. <a href="http://digilander.libero.it/i2ndt/grabber/grabber-compendium.htm" target="_blank">http://digilander.libero.it/i2ndt/grabber/grabber-compendium.htm</a> <a href="#fnref:21" class="footnote-back-ref">↩</a></p></li> <li id="fn:22"><p>"Weak signal modes". ARRL.org. American Radio Relay League. Retrieved 24 November 2019. <a href="http://www.arrl.org/weak-signal-modes" target="_blank">http://www.arrl.org/weak-signal-modes</a> <a href="#fnref:22" class="footnote-back-ref">↩</a></p></li> <li id="fn:23"><p>"Weak signal modes". ARRL.org. American Radio Relay League. Retrieved 24 November 2019. <a href="http://www.arrl.org/weak-signal-modes" target="_blank">http://www.arrl.org/weak-signal-modes</a> <a href="#fnref:23" class="footnote-back-ref">↩</a></p></li> <li id="fn:24"><p>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. <a href="/wiki/Joseph_Hooton_Taylor_Jr." target="_blank">/wiki/Joseph_Hooton_Taylor_Jr.</a> <a href="#fnref:24" class="footnote-back-ref">↩</a></p></li> <li id="fn:25"><p>"Weak signal modes". ARRL.org. American Radio Relay League. Retrieved 24 November 2019. <a href="http://www.arrl.org/weak-signal-modes" target="_blank">http://www.arrl.org/weak-signal-modes</a> <a href="#fnref:25" class="footnote-back-ref">↩</a></p></li> <li id="fn:26"><p>Chaffin, Kenny A. (February 1990). "Why QRP?". QST magazine. Newington, CT: ARRL. p. 43. Retrieved 24 November 2019. <a href="http://www.arrl.org/why-qrp" target="_blank">http://www.arrl.org/why-qrp</a> <a href="#fnref:26" class="footnote-back-ref">↩</a></p></li> <li id="fn:27"><p>Brown, George (2001). "CW QRP transmitter for 80 meters". Radio and Electronics Cookbook. Newnes. ISBN 978-0-7506-5214-8 – via Google Books. <a href="978-0-7506-5214-8" target="_blank">978-0-7506-5214-8</a> <a href="#fnref:27" class="footnote-back-ref">↩</a></p></li> <li id="fn:28"><p>Weiss, Adrian. The Five-Watt QRP Movement in the US, 1968-1981 (PDF) (Report). Miliwatt QRP Books. Retrieved 24 November 2019 – via n5dux.com/ham/files. <a href="http://www.n5dux.com/ham/files/pdf/QRP%20History%20-%20The%20Five-Watt%20QRP%20Movement%201968-1981.pdf" target="_blank">http://www.n5dux.com/ham/files/pdf/QRP%20History%20-%20The%20Five-Watt%20QRP%20Movement%201968-1981.pdf</a> <a href="#fnref:28" class="footnote-back-ref">↩</a></p></li> <li id="fn:29"><p>H. Ward Silver (25 February 2011). Ham Radio For Dummies. John Wiley & Sons. p. 218. ISBN 978-1-118-05419-2 – via Google Books. <a href="978-1-118-05419-2" target="_blank">978-1-118-05419-2</a> <a href="#fnref:29" class="footnote-back-ref">↩</a></p></li> <li id="fn:30"><p>Wells, Bradley (April 1984). "QRP: More than a state of mind". QST Magazine. Newington, CT: American Radio Relay League. p. 52. Retrieved 24 November 2019. <a href="http://www.arrl.org/qrp-more-than-a-state-of-mind" target="_blank">http://www.arrl.org/qrp-more-than-a-state-of-mind</a> <a href="#fnref:30" class="footnote-back-ref">↩</a></p></li> <li id="fn:31"><p>H. Ward Silver (25 February 2011). Ham Radio For Dummies. John Wiley & Sons. p. 218. ISBN 978-1-118-05419-2 – via Google Books. <a href="978-1-118-05419-2" target="_blank">978-1-118-05419-2</a> <a href="#fnref:31" class="footnote-back-ref">↩</a></p></li> <li id="fn:32"><p>"QRP – what, why, and how". ARRL.org. Newington, CT: American Radio Relay League. Archived from the original on 27 September 2007. Retrieved 4 April 2007. <a href="https://web.archive.org/web/20070927223047/http://www.arrl.org/tis/info/qrpwhtwy.html" target="_blank">https://web.archive.org/web/20070927223047/http://www.arrl.org/tis/info/qrpwhtwy.html</a> <a href="#fnref:32" class="footnote-back-ref">↩</a></p></li> </ol>