Editing Radio clock (section)

===Longwave and shortwave transmissions===
Radio clocks depend on coded time signals from radio stations. The stations vary in broadcast frequency, in geographic location, and in how the signal is modulated to identify the current time. In general, each station has its own format for the time code.

{{anchor|timecode radio stations}}

==== List of radio time signal stations ====
{| class="wikitable sortable"
|+ List of radio time signal stations
! Frequency !! Callsign !! Country Authority !! Location !! Aerial type !! Power !! Remarks
|-
| rowspan=6 | {{ntsh|25}} {{nowrap|25 kHz}} 
| <!--1-->[[RJH69]] || {{BLR}}<br />[[VNIIFTRI]] || [[Vileyka]]<br />{{coord|54|27|47|N|26|46|37|E|region:BY-MI_type:landmark|name=RJH69}} || Triple [[umbrella antenna]]<ref group=lower-alpha>3 umbrella antennas, fixed on 3 guyed tubular masts, insulated against ground with a height of {{cvt|305|m|ft}} and 15 guyed lattice masts with a height of {{cvt|270|m|ft}}</ref> || {{val|300|u=kW}} || rowspan=6 | This is [[Beta (time signal)|Beta time signal]].<ref name="vniiftri">{{Cite FTP |url=ftp://ftp.vniiftri.ru/BULLETINS/V/bull_b16_2018.pdf|title=Standard Time and Frequency Signals|access-date=2018-07-15|server=FTP server|url-status=dead|language=ru}} — official signal specification.</ref> The signal is transmitted in non-overlapping time:<br />02:00–02:20 UTC RAB99<br />04:00–04:25 UTC RJH86<br />06:00–06:20 UTC RAB99<br />07:00–07:25 UTC RJH69<br />08:00–08:25 UTC RJH90<br />09:00–09:25 UTC RJH77<br />10:00–10:25 UTC RJH86<br />11:00–11:20 UTC RJH63
|-
| <!--2-->RJH77 || {{RUS}}<br />[[VNIIFTRI]] || [[Arkhangelsk]]<br />{{coord|64|21|29|N|41|33|58|E|region:RU-ARK_type:landmark|name=RJH77}} || Triple umbrella antenna<ref group=lower-alpha>3 umbrella antennas, fixed on 18 guyed lattice masts, height of central masts: 305 metres</ref> || {{val|300|u=kW}} 
|-
| <!--3-->RJH63 || {{RUS}}<br />[[VNIIFTRI]] || [[Krasnodar]]<br />{{coord|44|46|25|N|39|32|50|E|name=RJH63}} || Umbrella antenna<ref group=lower-alpha>umbrella antenna, fixed on 13 guyed lattice masts, height of central mast: {{cvt|425|m|ft}}</ref> || {{val|300|u=kW}} 
|-
| <!--4-->RJH90 || {{RUS}}<br />[[VNIIFTRI]] || [[Nizhny Novgorod]]<br />{{coord|56|10|20|N|43|55|38|E|name=RJH90}} || Triple umbrella antenna<ref group=lower-alpha>3 umbrella antennas, fixed on 3 guyed tubular masts, insulated against ground with a height of {{cvt|205|m|ft}} and 15 guyed lattice masts with a height of {{cvt|170|m|ft}}</ref> || {{val|300|u=kW}} 
|-
| <!--5-->RJH86<ref name="vniiftri" /><ref group=lower-alpha>in air RJH66</ref> || {{KGZ}}<br />[[VNIIFTRI]] || [[Bishkek]]<br />{{coord|43|02|29|N|73|37|09|E|name=RJH86}} || Triple umbrella antenna<ref group=lower-alpha>3 umbrella antennas, fixed on 18 guyed lattice masts, height of central masts: {{cvt|276|m|ft}}</ref> || {{val|300|u=kW}}
|-
| <!--6-->RAB99 || {{RUS}}<br />[[VNIIFTRI]] || [[Khabarovsk]]<br />{{coord|48|29|29|N|134|48|59|E|name=RAB99}} || Umbrella antenna<ref group=lower-alpha>umbrella antenna, fixed on 18 guyed lattice masts arranged in 3 rows, height of central masts: {{cvt|238|m|ft}}</ref> || {{val|300|u=kW}} 
|-
| {{ntsh|40}} {{nowrap|40 kHz}} || <!--7-->[[JJY]] || {{JPN}}<br />[[National Institute of Information and Communications Technology|NICT]] || [[Otakadoyayama Transmitter|Mount Otakadoya]], [[Fukushima Prefecture|Fukushima]]<br />{{coord|37|22|21|N|140|50|56|E|name=JJY}} || [[T-Antenna|Capacitance hat]], height {{cvt|250|m|ft}} || {{val|50|u=kW}} || Located near [[Fukushima, Fukushima|Fukushima]]<ref name=McCarthy09 />
|-
| {{ntsh|50}} {{nowrap|50 kHz}} || <!--8-->[[RTZ (radio station)|RTZ]]|| {{RUS}}<br />[[VNIIFTRI]] || [[Irkutsk]]<br />{{coord|52|25|41|N|103|41|12|E|name=RTZ}} || Umbrella antenna || {{val|10|u=kW}} || [[Phase modulation|PM]] time code
|-
| rowspan=3 | {{ntsh|60}} {{nowrap|60 kHz}}
| <!--9-->[[JJY]] || {{JPN}}<br />[[National Institute of Information and Communications Technology|NICT]] || [[Haganeyama Transmitter|Mount Hagane]], [[Kyushu]]<br />{{coord|33|27|54|N|130|10|32|E|name=JJY}} || Capacitance hat, height {{cvt|200|m|ft}} || {{val|50|u=kW}} || Located on [[Kyūshū|Kyūshū Island]]<ref name=McCarthy09 />
|-
| <!--10-->[[Time from NPL|MSF]] || {{GBR}}<br />[[National Physical Laboratory (United Kingdom)|NPL]] || [[Anthorn Radio Station|Anthorn, Cumbria]]<br />{{coord|54|54|27|N|03|16|24|W|name=MSF|notes={{efn|Before 1 April 2007, the signal was transmitted from [[Rugby Radio Station|Rugby, Warwickshire]] {{coord|52|21|33|N|01|11|21|W}}}}}} || Triple T-antenna<ref group=lower-alpha>3 T-antennas, spun {{cvt|150|m|ft}} above ground between two {{cvt|227|m|ft}} high guyed grounded masts in a distance of {{cvt|655|m|yd}}</ref> || {{val|17|u=kW}} || Range up to {{cvt|1500|km|mi}}
|-
| <!--11-->[[WWVB]] || {{USA}}<br />[[National Institute of Standards and Technology|NIST]] || Near [[Fort Collins, Colorado]]<ref>{{cite journal|title=NIST Radio Station WWVB|date=March 2010|url=https://www.nist.gov/pml/div688/grp40/wwvb.cfm|journal=NIST|access-date=18 March 2014|archive-date=25 March 2014|archive-url=https://web.archive.org/web/20140325181329/http://www.nist.gov/pml/div688/grp40/wwvb.cfm|url-status=live}}</ref><br />{{coord|40|40|41|N|105|02|48|W|name=WWVB}} || Two capacitance hats, height {{cvt|122|m|ft}} || {{val|70|u=kW}} || Received through most of mainland U.S.<ref name=McCarthy09 />
|-
| {{ntsh|66.66}} {{nowrap|66.66 kHz}} || <!--12-->[[RBU (radio station)|RBU]] || {{RUS}}<br />[[VNIIFTRI]] || [[Taldom]], [[Moscow]]<br />{{coord|56|43|59|N|37|39|47|E|name=RBU|notes={{efn|name=RBU|Before 2008, transmitter located at {{coord|55|44|14|N|38|09|04|E}}}}}} || Umbrella antenna<ref group=lower-alpha>umbrella antenna, fixed on a {{cvt|275|m|ft}} high central tower insulated against ground and five {{cvt|257|m|ft}} high lattice masts insulated against ground in a distance of {{convert|324|m|yd|abbr=off}} from the central tower</ref> || {{val|50|u=kW}} || [[Phase modulation|PM]] time code
|-
| {{ntsh|68.5}} {{nowrap|68.5 kHz}} || <!--13-->[[BPC (time signal)|BPC]] || {{CHN}}<br />[[National Time Service Center|NTSC]] || [[Shangqiu]], [[Henan]]<br />{{coord|34|27|25|N|115|50|13|E|name=BPC}} || 4 guyed masts, arranged in a square || {{val|90|u=kW}} || 21 hours per day, with a 3-hour break from 05:00–08:00 ([[China Standard Time]]) daily (21:00–24:00 UTC)<ref>{{cite web|title=BPC|url=http://www.time.ac.cn/serve/e_c.htm|work=National Time Service Center, Chinese Academy of Sciences|access-date=16 March 2013|archive-url=https://web.archive.org/web/20180214031330/http://www.time.ac.cn/serve/e_c.htm|archive-date=February 14, 2018 |url-status=dead}}</ref>
|-
| {{ntsh|75}} <s>{{nowrap|75 kHz}}</s> || <!--14--><s>[[HBG Prangins|HBG]]</s> || {{flagdeco|Switzerland}} <s>[[Switzerland]]</s><br /><s>[[Swiss Federal Office of Metrology|METAS]]</s> || <s>[[Prangins]]</s><br /><s>{{coord|46|24|24|N|06|15|04|E|name=HBG}}</s> || <s>T-antenna</s><ref group=lower-alpha>T-antenna spun between two {{cvt|125|m|ft}} tall, grounded free-standing lattice towers in a distance of {{cvt|227|m|yd}}</ref> || <s>{{val|20|u=kW}}</s> || Discontinued as of 1 January 2012
|-
| rowspan=2 | {{ntsh|77.5}} {{nowrap|77.5 kHz}} 
| <!--15-->[[DCF77]] || {{DEU}}<br />[[Physikalisch-Technische Bundesanstalt|PTB]] || [[Mainflingen]], [[Hessen]]<br />{{coord|50|00|58|N|09|00|29|E|name=DCF77}} || Vertical omni-directional antennas with top-loading capacity, height {{convert|150|m|ft}}<ref>{{cite web |url=http://www.ptb.de/en/org/4/44/442/dcf77_sende_e.htm |title=DCF77 transmitting facilities |author=Yvonne Zimber |date=2007-05-09 |access-date=2010-05-02 |archive-date=2010-05-14 |archive-url=https://web.archive.org/web/20100514002918/http://www.ptb.de/en/org/4/44/442/dcf77_sende_e.htm |url-status=live }}</ref> || {{val|50|u=kW}} || Located southeast of Frankfurt am Main with a range of up to {{cvt|2000|km|mi}}<ref name=McCarthy09>Dennis D. McCarthy, P. Kenneth Seidelmann ''Time: From Earth Rotation to Atomic Physics'' Wiley-VCH, 2009 {{ISBN|3-527-40780-4}} page 257</ref><ref name="compuphase_h0420">{{cite web|title=Synchronizing time with DCF77 and MSF60|url=http://www.compuphase.com/mp3/h0420_timecode.htm|access-date=2011-09-12|archive-date=2011-01-12|archive-url=https://web.archive.org/web/20110112034340/http://www.compuphase.com/mp3/h0420_timecode.htm|url-status=live}} 090917 compuphase.com</ref>
|-
| <!--16-->[[BSF (time service)|BSF]] || {{TWN}} || [[Zhongli District|Zhongli]]<br />{{coord|25|00|19|N|121|21|55|E|name=BSF}} || T-antenna<ref group=lower-alpha>T-antenna spun between two telecommunication towers in a distance of {{cvt|33|m|yd}}</ref> || ||<ref>{{cite web|url=http://lfintaiwan.bitbucket.io/overview.html|title=A Time Station Signal Project for Taiwan|access-date=2018-07-09|archive-date=2017-04-20|archive-url=https://web.archive.org/web/20170420145738/https://lfintaiwan.bitbucket.io/overview.html|url-status=live}}</ref>
|-
| bgcolor=silver rowspan=3 | {{ntsh|100}} {{nowrap|100 kHz}}<ref group=lower-alpha>Frequency for radio navigation system</ref>
| <!--17-->[[BPL (time service)|BPL]] || {{CHN}}<br />[[National Time Service Center|NTSC]] || [[Pucheng County, Shaanxi|Pucheng]], [[Shaanxi]]<br />{{coord|34|56|56|N|109|32|35|E|name=BPL}} || Single guyed lattice steel mast || {{val|800|u=kW}} || [[Loran-C]] compatible format signal on air from 05:30 to 13:30 UTC,<ref>{{cite web|title=长波授时 (Longwave time signal)|url=http://www.time.ac.cn/serve/BPL.htm|work=National Time Service Center, Chinese Academy of Sciences|access-date=16 March 2013|archive-date=10 January 2013|archive-url=https://web.archive.org/web/20130110210025/http://www.time.ac.cn/serve/BPL.htm|url-status=dead}}</ref> with a reception radius up to {{cvt|3000|km|mi}}<ref>{{cite web|title=科研成果 (Research achievements)|url=http://www.ntsc.cas.cn/kycg/|work=National Time Service Center, Chinese Academy of Sciences|access-date=16 March 2013|archive-date=17 April 2013|archive-url=https://web.archive.org/web/20130417182930/http://www.ntsc.cas.cn/kycg/|url-status=live}}</ref> 
|-
| <!--18-->RNS-E || {{RUS}}<br />[[VNIIFTRI]] || [[Bryansk]]<br />{{coord|53|08|00|N|34|55|00|E|name=RNS-E}} || 5 guyed masts || {{val|800|u=kW}} || [[CHAYKA]] compatible format signal<ref name="vniiftri" /><br />04:00–10:00 UTC and 14:00–18:00 UTC
|-
| <!--19-->RNS-V || {{RUS}}<br />[[VNIIFTRI]] || [[Alexandrovsk-Sakhalinsky (town)|Alexandrovsk-Sakhalinsky]]<br />{{coord|51|05|00|N|142|43|00|E|name=RNS-V}} || Single guyed mast || {{val|400|u=kW}} || [[CHAYKA]] compatible format signal<ref name="vniiftri" /><br />23:00–05:00 UTC and 11:00–17:00 UTC
|-
| bgcolor=lightgrey | {{ntsh|129.1}} {{nowrap|129.1 kHz}}<ref group=lower-alpha name="teleswitch">Frequency for radio teleswitch system</ref>|| <!--20-->DCF49 || {{DEU}}<br />[[Physikalisch-Technische Bundesanstalt|PTB]] || [[Mainflingen]]<br />{{coord|50|00|58|N|09|00|29|E|region:DE-HE_type:landmark|name=DCF49}} || T-antenna || {{val|100|u=kW}} || rowspan=3 | [[Radio teleswitch|EFR radio teleswitch]]<ref name="efr">{{cite web |title=PTB time monitor |url=http://www.efr.de/de/efr-system/#/PTB-Zeitmonitor |access-date=2018-07-16 |archive-date=2018-07-16 |archive-url=https://web.archive.org/web/20180716194814/http://www.efr.de/de/efr-system/#/PTB-Zeitmonitor |url-status=live }}&nbsp;— in German</ref><br />time signal only (no reference frequency)<br />FSK ± 170&nbsp;Hz 200 baud
|-
| bgcolor=lightgrey | {{ntsh|135.6}} {{nowrap|135.6 kHz}}<ref group=lower-alpha name="teleswitch" />|| <!--21-->HGA22 || {{HUN}}<br />[[Physikalisch-Technische Bundesanstalt|PTB]] || [[Lakihegy]]<br />{{coord|47|22|24|N|19|00|17|E|region:HU-PE_type:landmark|name=HGA22}} || Single guyed mast || {{val|100|u=kW}} 
|-
| bgcolor=lightgrey | {{ntsh|139}} {{nowrap|139 kHz}}<ref group=lower-alpha name="teleswitch" />|| <!--22-->DCF39 || {{DEU}}<br />[[Physikalisch-Technische Bundesanstalt|PTB]] || [[Burg bei Magdeburg]]<br />{{coord|52|17|13|N|11|53|49|E|region:DE-ST_type:landmark|name=DCF39}} || Single guyed mast || {{val|50|u=kW}} 
|-
| bgcolor=silver | {{ntsh|162}} {{nowrap|162 kHz}}<ref group=lower-alpha name="AM">Frequency for AM-broadcasting</ref>|| <!--23-->[[ALS162 time signal|ALS162]] || {{FRA}}<br />{{ill|ANFR|fr|display=1}} || [[Allouis]]<br />{{coord|47|10|10|N|02|12|16|E|name=ALS162}} || Two guyed steel lattice masts, height {{cvt|350|m|ft}}, fed on the top || {{val|800|u=kW}}|| AM-broadcasting transmitter, located {{cvt|150|km|mi}} south of Paris with a range of up to {{cvt|3500|km|mi}}, using [[Phase modulation|PM]] with encoding similar to DCF77<ref group=lower-alpha>and requiring a more complex receiver for demodulating time signal</ref>
|-<!-- Frequency ! Callsign ! Country ! Location ! Aerial type ! Power ! Remarks -->
| bgcolor=silver | {{ntsh|198}} {{nowrap|198 kHz}}<ref group=lower-alpha name="AM" /><ref group=lower-alpha>since 1988, before 200 kHz</ref> || <!--24-->{{nowrap|[[BBC Radio 4]]}} || {{GBR}}<br />[[National Physical Laboratory (United Kingdom)|NPL]] || [[Droitwich Transmitting Station|Droitwich]]<br />{{coord|52.2955|N|2.1063|W|type:landmark|name=BBC4}} || [[T-antenna|T-aerial]]<ref group=lower-alpha>Droitwich uses a T-aerial suspended between two {{nowrap|213 metres}} (699') guyed steel lattice [[radio masts and towers|radio masts]], which stand {{cvt|180|m|yd}} apart.</ref> || {{val|500|u=kW}}<ref>{{cite web
| title=Radio stations in London, England
| access-date=2016-04-26
| url=https://radiomap.eu/uk/london
| quote=Birmingham, Droitwich, 500 kW + Blackwall Tunnel + Rotherhithe Tunnel
| archive-date=2016-04-19
| archive-url=https://web.archive.org/web/20160419145438/http://radiomap.eu/uk/london
| url-status=live
}}</ref> || Additional {{nowrap|(50 kW)}} transmitters is at [[Burghead Transmitting Station|Burghead]] and [[Westerglen transmitting station|Westerglen]]. The time signal is transmitted by {{nowrap|25-bit/s}} phase modulation.<ref>{{cite web
| title=L.F. RADIO-DATA: Specification of BBC phase-modulated transmissions on long-wave
| date=December 1984
| publication-date=2006-10-24
| url=https://downloads.bbc.co.uk/rd/pubs/reports/1984-19.pdf
| quote=The BBC long-wave a.m. transmitter network carries a low bit-rate data signal, in addition to the normal programme signal modulation. The data signal is conveyed by phase-modulation of the carrier
| access-date=2016-04-25
| archive-date=2016-03-04
| archive-url=https://web.archive.org/web/20160304194431/http://downloads.bbc.co.uk/rd/pubs/reports/1984-19.pdf
| url-status=live
}}</ref>
|-
| bgcolor=PaleGreen rowspan=3 | {{ntsh|2500}} {{nowrap|2.5 MHz}}
| <!--25-->[[BPM (time service)|BPM]] || {{CHN}}<br />[[National Time Service Center|NTSC]] || [[Pucheng County, Shaanxi|Pucheng]], [[Shaanxi]]<br />{{coord|34|56|56|N|109|32|35|E|name=BPM}} || || || (BCD time code on 125&nbsp;Hz sub-carrier not yet activated)<br />
07:30–01:00 UTC<ref name=bpm>{{cite web|title=短波授时 (Shortwave time signal)|url=http://www.time.ac.cn/serve/BPM.htm|work=National Time Service Center, Chinese Academy of Sciences|access-date=2013-03-16|archive-date=2013-01-15|archive-url=https://web.archive.org/web/20130115032133/http://www.time.ac.cn/serve/BPM.htm|url-status=live}}</ref> 
|-
| <!--26-->[[WWV (radio station)|WWV]] || {{USA}}<br />[[National Institute of Standards and Technology|NIST]] || Near [[Fort Collins, Colorado]]<br />{{coord|40|40|41|N|105|02|48|W|name=WWV}} || Broadband monopole || {{val|2.5|u=kW}} ||rowspan=2| [[Binary-coded decimal|Binary-coded decimal (BCD)]] time code on {{nowrap|100 Hz}} sub-carrier
|-
| <!--27-->[[WWVH]] || {{USA}}<br />[[National Institute of Standards and Technology|NIST]] || [[Kekaha, Hawaii]]<br />{{coord|21|59|16|N|159|45|46|W|name=WWVH}} || || {{val|5|u=kW}}
|-
| {{ntsh|3330}} {{nowrap|3.33 MHz}} || <!--28-->[[CHU (radio station)|CHU]] || {{CAN}}<br />[[National Research Council (Canada)|NRC]] || [[Ottawa, Ontario]]<br />{{coord|45|17|40|N|75|45|27|W|name=CHU}} || || {{val|3|u=kW}} || 300 baud [[Bell 103]] time code
|-
| bgcolor=LightGreen| {{ntsh|4996}} {{nowrap|4.996 MHz}} || <!--29-->[[RWM]] || {{RUS}}<br />[[VNIIFTRI]] || [[Taldom]], [[Moscow]]<br />{{coord|56|44|58|N|37|38|23|E|name=RWM|notes={{efn|name=RBU}}}} || || {{val|10|u=kW}} || [[Continuous wave|CW]] ({{Val|1|u=Hz}}, {{Val|10|u=Hz}})
|-
| bgcolor=LightGreen rowspan=5 | {{ntsh|5000}} {{nowrap|5 MHz}}
| <!--30-->[[BPM (time service)|BPM]] || {{CHN}}<br />[[National Time Service Center|NTSC]] ||[[Pucheng County, Shaanxi|Pucheng]], [[Shaanxi]]<br />{{coord|34|56|56|N|109|32|35|E|name=BPM}} || || || BCD time code on 125&nbsp;Hz sub-carrier.<br />00:00–24:00 UTC<ref name=bpm />
|-
| <!--31-->[[HLA (radio station)|HLA]] || {{KOR}}<br />[[Korea Research Institute of Standards and Science|KRISS]] || [[Daejeon]]<br />{{coord|36|23|14|N|127|21|59|E|name=HLA}} || || {{val|2|u=kW}} ||
|-
| <!--32-->[[WWV (radio station)|WWV]] || {{USA}}<br />[[National Institute of Standards and Technology|NIST]] || Near [[Fort Collins, Colorado]]<br />{{coord|40|40|41|N|105|02|48|W|name=WWV}} || Broadband monopole || {{val|10|u=kW}}<ref group=lower-alpha>Time signal article says 2.5 kW</ref> ||rowspan=2| BCD time code on {{nowrap|100 Hz}} sub-carrier
|-
| <!--33-->[[WWVH]] || {{USA}}<br />[[National Institute of Standards and Technology|NIST]] || [[Kekaha, Hawaii]]<br />{{coord|21|59|16|N|159|45|46|W|name=WWVH}} || || {{val|10|u=kW}}
|-
| <!--34-->[[YVTO]] || {{VEN}} || [[Caracas]]<br/>{{coord|10|30|13|N|66|55|44|W|region:VE-A_type:landmark|name=YVTO}} || || {{val|1|u=kW}} ||
|-
| {{ntsh|7850}} {{nowrap|7.85 MHz}} || <!--35-->[[CHU (radio station)|CHU]] || {{CAN}}<br />[[National Research Council (Canada)|NRC]] || [[Ottawa, Ontario]]<br />{{coord|45|17|40|N|75|45|27|W|name=CHU}} || || {{val|10|u=kW}} || {{nowrap|300 baud}} [[Bell 103]] time code
|-
| bgcolor=PaleGreen| {{ntsh|9996}} {{nowrap|9.996 MHz}} || <!--36-->[[RWM]] || {{RUS}}<br />[[VNIIFTRI]] || [[Taldom]], [[Moscow]]<br />{{coord|56|44|58|N|37|38|23|E|name=RWM|notes={{efn|name=RBU}}}} || || {{val|10|u=kW}} || [[Continuous wave|CW]] ({{Val|1|u=Hz}}, {{Val|10|u=Hz}})
|-
| bgcolor=PaleGreen rowspan=5 | {{ntsh|10000}} {{nowrap|10 MHz}}
| <!--37-->[[BPM (time service)|BPM]] || {{CHN}}<br />[[National Time Service Center|NTSC]] || [[Pucheng County, Shaanxi|Pucheng]], [[Shaanxi]] <br />{{coord|34|56|56|N|109|32|35|E|name=BPM}} || || || (BCD time code on 125&nbsp;Hz sub-carrier not yet activated)<br />00:00–24:00 UTC<ref name=bpm />
|-
| <!--38-->[[LOL (radio station)|LOL]] || {{ARG}}<br />[[Argentine Naval Hydrographic Service|SHN]] || [[Buenos Aires]]{{refn|group=lower-alpha|<ref name="lol">[http://www.hidro.gov.ar/Observatorio/LaHora.asp Information on the Official Time and Standard Frequency] {{Webarchive|url=https://web.archive.org/web/20180828134617/http://www.hidro.gov.ar/Observatorio/LaHora.asp |date=2018-08-28 }} — in Spanish</ref><!-- http://www.hidro.gov.ar/Observatorio/LaHora.asp (http://web.archive.org/web/20211211001540/http://www.hidro.gov.ar/Observatorio/LaHora.asp) --> says that the transmitter is located in Observatorio Naval Buenos Aires at Avenida España 2099, Buenos Aires; on Google Street View, some antenna structures can be seen both on and near the building, however, it's unclear where exactly the specific antenna is located. The coordinates here point to the building itself. <!--br/-->{{coord|34|37|19|S|58|21|18|W|name=LOL}}}} || || {{val|2|u=kW}} || Observatorio Naval Buenos Aires<ref name="lol" />
|-
| <!--39-->[[WWV (radio station)|WWV]] || {{USA}}<br />[[National Institute of Standards and Technology|NIST]] || Near [[Fort Collins, Colorado]]<br />{{coord|40|40|41|N|105|02|48|W|name=WWV}} || Broadband monopole || {{val|10|u=kW}} ||rowspan=2| BCD time code on {{nowrap|100 Hz}} sub-carrier
|-
| <!--40-->[[WWVH]] || {{USA}}<br />[[National Institute of Standards and Technology|NIST]] || [[Kekaha, Hawaii]]<br />{{coord|21|59|16|N|159|45|46|W|name=WWVH}} || || {{val|10|u=kW}}
|-
| <!--41-->[[PPE (radio station)|PPE]]<ref name="onrdsh">{{cite web|url=http://pcdsh01.on.br/RadioDifusaoSinaisHorarios.html|title=Rádio-Difusão de Sinais Horários|publisher=Observatório Nacional|access-date=2012-02-23|archive-date=2014-03-12|archive-url=https://web.archive.org/web/20140312212423/http://pcdsh01.on.br/RadioDifusaoSinaisHorarios.html|url-status=live}}</ref> || {{BRA}} || [[Rio de Janeiro, RJ]] {{coord|22|53|44|S|43|13|27|W|name=PPE}}<ref name="onrdsh" /> || Horizontal [[Dipole antenna#Half-wave antenna|half-wavelength dipole]]<ref name="onrdsh" /> || {{val|1|u=kW}}<ref name="onrdsh" /> || Maintained by [[National Observatory (Brazil)]]
|-
| {{ntsh|14670}} {{nowrap|14.67 MHz}} || <!--42-->[[CHU (radio station)|CHU]] || {{CAN}}<br />[[National Research Council (Canada)|NRC]] || [[Ottawa, Ontario]]<br />{{coord|45|17|40|N|75|45|27|W|name=CHU}} || || {{val|3|u=kW}} || 300 baud [[Bell 103]] time code
|-
| bgcolor=LightGreen| {{ntsh|14996}} {{nowrap|14.996 MHz}} || <!--43-->[[RWM]] || {{RUS}}<br />[[VNIIFTRI]] || [[Taldom]], [[Moscow]]<br />{{coord|56|44|58|N|37|38|23|E|name=RWM|notes={{efn|name=RBU}}}} || || {{val|10|u=kW}} || [[Continuous wave|CW]] ({{Val|1|u=Hz}}, {{Val|10|u=Hz}})
|-
| bgcolor=LightGreen rowspan=3 | {{ntsh|15000}} {{nowrap|15 MHz}}
| <!--44-->[[BPM (time service)|BPM]] || {{CHN}}<br />[[National Time Service Center|NTSC]] || [[Pucheng County, Shaanxi|Pucheng]], [[Shaanxi]] <br />{{coord|34|56|56|N|109|32|35|E|name=BPM}} || || || (BCD time code on 125&nbsp;Hz sub-carrier not yet activated)<br />01:00–09:00 UTC<ref name=bpm />
|-
| <!--45-->[[WWV (radio station)|WWV]] || {{USA}}<br />[[National Institute of Standards and Technology|NIST]] || Near [[Fort Collins, Colorado]]<br />{{coord|40|40|41|N|105|02|48|W|name=WWV}} || Broadband monopole || {{val|10|u=kW}} ||rowspan=2| BCD time code on {{nowrap|100 Hz}} sub-carrier
|-
| <!--46-->[[WWVH]] || {{USA}}<br />[[National Institute of Standards and Technology|NIST]] || [[Kekaha, Hawaii]]<br />{{coord|21|59|16|N|159|45|46|W|name=WWVH}} || || {{val|10|u=kW}}
|-
| bgcolor=PaleGreen| {{ntsh|20000}} {{nowrap|20 MHz}} || | <!--47-->[[WWV (radio station)|WWV]] || {{USA}}<br />[[National Institute of Standards and Technology|NIST]] || Near [[Fort Collins, Colorado]]<br />{{coord|40|40|41|N|105|02|48|W|name=WWV}} || Broadband monopole || {{val|2.5|u=kW}} || BCD time code on {{nowrap|100 Hz}} sub-carrier
|-
| bgcolor=LightGreen rowspan=2 | {{ntsh|25000}} {{nowrap|25 MHz}} || <!--48-->[[WWV (radio station)|WWV]] || {{USA}}<br />[[National Institute of Standards and Technology|NIST]] || Near [[Fort Collins, Colorado]]<br />{{coord|40|40|41|N|105|02|48|W|name=WWV}} || Broadband monopole || {{val|2.0|u=kW}} || Schedule: variable (experimental broadcast)
|-
| <!--49--><s>[[MIKES (radio station)|MIKES]]</s> || <s>{{FIN}}<br />[[Centre for Metrology and Accreditation|MIKES]]</s> || <s>[[Espoo, Finland]]<br /> {{coord|60|10|49|N|24|49|35|E|region:FI-18_type:landmark|name=MIKES time signal transmitter}}</s> || <s>λ/4 [[sloper antenna]]</s> || <s>{{val|0.2|u=kW}}</s><ref name=MIKES>{{cite web |title=QSL: MIKES Time Station, Espoo, Finland |date=14 May 2014 |url=http://swldx.us/blog/?p=821 |website=SWL DX Blog |access-date=2016-10-11 |archive-date=2016-10-12 |archive-url=https://web.archive.org/web/20161012151307/http://swldx.us/blog/?p=821 |url-status=live }} Reproduces a [[QSL card|QSL letter]] from MIKES with technical details.</ref> || <s>1&nbsp;kHz amplitude modulation similar to DCF77.</s><br />As of 2017 the transmission is discontinued until further notice.<ref name="BIPM">BIPM Annual Report on Time Activities – [https://web.archive.org/web/20211010023818/ftp://ftp2.bipm.org/pub/tai/scale/TIMESIGNALS/timesignals.pdf Time Signals] , retrieved 2018 July 31.</ref><br/>"MIKES has a transmitter for time code and precise 25 MHz frequency for those near the Helsinki metropolitan area who need precise time and frequency."<ref>{{cite web | url=https://www.vttresearch.com/en/si-units-finland-time-and-frequency | title=SI units in Finland, time and frequency &#124; }}</ref>
|}

'''Descriptions'''
{{Reflist|group=lower-alpha}}

{{Location map+ |World
|width          = 1000
|float          = none
|border         = 
|caption        = 
|alt            = 
|relief         = 
|AlternativeMap = 
|overlay_image  = 
|places         = 
 <!-- 1-->{{Location map~ |World |coordinates={{coord|54|27|47|N| 26|46|37|E}} |label=<span style="position:relative; left:0.5em">[[RJH69]]<span style="visibility:hidden">RJH6</span><br/><span style="visibility:hidden">/</span>{{pipe}}<br/><span style="visibility:hidden">/</span>{{pipe}}<br/>/<span style="visibility:hidden">{{pipe}}</span></span> |position=top}}
 <!-- 2-->{{Location map~ |World |coordinates={{coord|64|21|29|N| 41|33|58|E}} |label=<span style="visibility:hidden">JH77</span>RJH77<!-- <br/>↓ --> |position=top}}
 <!-- 3-->{{Location map~ |World |coordinates={{coord|44|46|25|N| 39|32|50|E}} |label=RJH63 |position=}}
 <!-- 4-->{{Location map~ |World |coordinates={{coord|56|10|20|N| 43|55|38|E}} |label=←&nbsp;RJH90 |position=right}}
 <!-- 5-->{{Location map~ |World |coordinates={{coord|43| 2|29|N| 73|37| 9|E}} |label=RJH86 |position=right<!-- top -->}}
 <!-- 6-->{{Location map~ |World |coordinates={{coord|48|29|29|N|134|48|59|E}} |label=RAB99 |position=}}
 <!-- 7-->{{Location map~ |World |coordinates={{coord|37|22|21|N|140|50|56|E}} |label=[[Otakadoyayama Transmitter|JJY<br/><small>(Mt&nbsp;Otakadoya)</small>]] |position=right |mark=Green pog.svg}}
 <!-- 8-->{{Location map~ |World |coordinates={{coord|52|25|41|N|103|41|12|E}} |label=[[RTZ (radio station)|RTZ]]<span style="visibility:hidden">RT</span> |position=top |mark=Green pog.svg}}
 <!-- 9-->{{Location map~ |World |coordinates={{coord|33|27|54|N|130|10|32|E}} |label=<span style="position:relative; left:-5px; top:1em">[[Haganeyama Transmitter|JJY<br/><small>(Mt&nbsp;Hagane)</small>]]</span> |position=right |mark=Green pog.svg}}
 <!--10-->{{Location map~ |World |coordinates={{coord|54|54|27|N|  3|16|24|W}} |label=MSF<br/>↓ |position=top |mark=Green pog.svg}}
 <!--11, 26, 32, 39, 45, 47, 48
       -->{{Location map~ |World |coordinates={{coord|40|40|41|N|105|02|48|W}} |label=[[WWV (radio station)|WWV]],&nbsp;[[WWVB]] |position=bottom |mark=Green-blue dot.svg}}
 <!--12-->{{Location map~ |World |coordinates={{coord|56|43|59|N| 37|39|47|E}} |label=<!-- <span style="position:relative; left:-3px; top:-0.5em">↙︎<span style="position:relative; top:-0.25em> --><span style="position:relative; left:-2px; top:0.8em">↖︎<span style="position:relative; top:0.5em">[[RBU (radio station)|RBU]],&nbsp;[[RWM]]</span></span> |position=right |mark=Green-blue dot.svg}}
 <!--13-->{{Location map~ |World |coordinates={{coord|34|27|23|N|115|50|13|E}} |label=<span style="position:relative; left:3px; top:0.75em"><span style="position:relative; top:0.75em>[[BPC (time signal)|BPC]]</span>↗︎</span> |position=left |mark=Green pog.svg}}
 <!--14-->{{Location map~ |World |coordinates={{coord|46|24|24|N|  6|15| 4|E}} |label=↑&nbsp;<br/>[[HBG Prangins|HBG]]<span style="visibility:hidden">HBG</span> |position=bottom |mark=Black pog.svg}}
 <!--15, 207
       -->{{Location map~ |World |coordinates={{coord|50| 0|58|N|  9| 0|29|E}} |label={{pipe}}<br/>{{pipe}}<br/>{{pipe}}<br/>{{pipe}}<br/>DCF49,&nbsp;[[DCF77]]<span style="visibility:hidden">DCF49,&nbsp;DCF7</span> |position=bottom |mark=Red-green dot.svg}}
 <!--16-->{{Location map~ |World |coordinates={{coord|25| 0|19|N|121|21|55|E}} |label=[[BSF (time service)|BSF]] |position=bottom |mark=Green pog.svg}}
 <!--17, 25, 30, 37, 44
       -->{{Location map~ |World |coordinates={{coord|34|56|56|N|109|32|35|E}} |label=<span style="position:relative; top:-0.2em">[[BPL (time service)|BPL]],&nbsp;[[BPM (time service)|BPM]]</span> |position=left |mark=Red-blue dot.svg}}
 <!--18-->{{Location map~ |World |coordinates={{coord|53| 8| 0|N| 34|55| 0|E}} |label={{pipe}}<br/>{{pipe}}<br/><span style="visibility:hidden">NS-E</span>RNS-E |position=bottom}}
 <!--19-->{{Location map~ |World |coordinates={{coord|51| 5| 0|N|142|43| 0|E}} |label=<span style="position:relative; top:-0.6em">RNS-V</span> |position=right}}
 <!--20 — see above (15)-->
 <!--21-->{{Location map~ |World |coordinates={{coord|47|22|24|N| 19| 0|17|E}} |label=HGA22 |position=bottom}}
 <!--22-->{{Location map~ |World |coordinates={{coord|52|17|13|N| 11|53|49|E}} |label=DCF39 |position=top}}
 <!--23-->{{Location map~ |World |coordinates={{coord|47|10|10|N|  2|12|16|E}} |label=<span style="position:relative; left:4px; top:0.85em"><span style="position:relative; top:0.5em">[[Télé Distribution Française|TDF]]</span>↗︎</span> |position=left}}
 <!--24-->{{Location map~ |World |coordinates={{coord|52.2955|N|2.1063|W}} |label=<span style="position:relative; left:-3px; top:1em"><span style="position:relative; top:0.4em">[[BBC&nbsp;Radio&nbsp;4]]&nbsp;</span>↗︎</span> |position=left}}
 <!--25 — see above (17)-->
 <!--26 — see abobe (11)-->
 <!--27, 33, 40, 46
       -->{{Location map~ |World |coordinates={{coord|21|59|16|N|159|45|46|W}} |label=[[WWVH]] |position=top |mark=Blue pog.svg}}
 <!--28, 35, 42
       -->{{Location map~ |World |coordinates={{coord|45|17|40|N| 75|45|27|W}} |label=[[CHU (radio station)|CHU]] |position=top |mark=Blue pog.svg}}
 <!--29, 36, 43
       --><!-- {{Location map~ |World |coordinates={{coord|55|44|14|N| 38| 9| 4|E}} |label=<span style="position:relative; left:-3px; top:0.9em">↖︎<span style="position:relative; top:0.2em">[[RWM]]</span></span> |position=right}} -->
 <!--30 — see above (17)-->
 <!--31-->{{Location map~ |World |coordinates={{coord|36|23|14|N|127|21|59|E}} |label=[[HLA (radio station)|HLA]] |position=top |mark=Blue pog.svg}}
 <!--32 — see above (11)-->
 <!--33 — see above (27)-->
 <!--34-->{{Location map~ |World |coordinates={{coord|10|30|13|N| 66|55|44|W}} |label=<span style="visibility:hidden">VTO</span>[[YVTO]] |position=top |mark=Blue pog.svg}}
 <!--35 — see above (28)-->
 <!--36 — see above (29)-->
 <!--37 — see above (17)-->
 <!--38-->{{Location map~ |World |coordinates={{coord|34|37|19|S| 58|21|18|W}} |label=<span style="position:relative; top:0.75em">[[LOL (radio station)|LOL]]</span> |position= |mark=Blue pog.svg}}
 <!--39 — see above (11)-->
 <!--40 — see above (27)-->
 <!--41-->{{Location map~ |World |coordinates={{coord|22|53|44|S| 43|13|27|W}} |label=<span style="visibility:hidden">PE</span>[[PPE (radio station)|PPE]] |position=bottom |mark=Blue pog.svg}}
 <!--42 — see above (28)-->
 <!--43 — see above (29)-->
 <!--44 — see above (17)-->
 <!--45 — see above (11)-->
 <!--46 — see above (27)-->
 <!--47 — see above (11)-->
 <!--48 — see above (11)-->
 <!--49-->{{Location map~ |World |coordinates={{coord|60|10|49|N| 24|49|35|E}} |label=[[MIKES (radio station)|MIKES]]<span style="visibility:hidden">MIKE</span> |position=top |mark=Black pog.svg}}
<!-- template for new lines:
 {{Location map~ |World |coordinates= |label= |position=}}
-->
}}<!--
A current list of times signal stations is published by the [[BIPM]] as an appendix to their annual report; the appendix includes coordinates of transmitter sites, operating schedules for stations, and the uncertainty of the [[carrier frequency]] of transmitters.<ref>[http://www.bipm.org/utils/en/pdf/time_ann_rep/Time_annual_report_2010.pdf#page=85 BIPM Annual Report on Time Activities 2010] {{Webarchive|url=https://web.archive.org/web/20120331030327/http://www.bipm.org/utils/en/pdf/time_ann_rep/Time_annual_report_2010.pdf#page=85 |date=2012-03-31 }}, pages 85–93, retrieved 2011 September 12.</ref><ref name="BIPM">BIPM Annual Report on Time Activities – [https://web.archive.org/web/20211010023818/ftp://ftp2.bipm.org/pub/tai/scale/TIMESIGNALS/timesignals.pdf Time Signals] , retrieved 2018 July 31.</ref>-->

Many other countries can receive these signals ([[JJY]] can sometimes be received in New Zealand, Western Australia, Tasmania, Southeast Asia, parts of Western Europe and the Pacific Northwest of North America at night), but success depends on the time of day, atmospheric conditions, and interference from intervening buildings. Reception is generally better if the clock is placed near a window facing the transmitter. There is also a propagation delay of approximately {{nowrap|1 ms}} for every {{cvt|300|km|mi}} the receiver is from the transmitter.

====Clock receivers====
A number of manufacturers and retailers sell radio clocks that receive coded time signals from a radio station, which, in turn, derives the time from a true atomic clock.

One of the first radio clocks was offered by [[Heathkit]] in late 1983. Their model GC-1000 "Most Accurate Clock" received shortwave time signals from radio station [[WWV (radio station)|WWV]] in [[Fort Collins, Colorado]]. It automatically switched between WWV's 5, 10, and 15&nbsp;MHz frequencies to find the strongest signal as conditions changed through the day and year. It kept time during periods of poor reception with a quartz-crystal [[oscillator]]. This oscillator was disciplined, meaning that the microprocessor-based clock used the highly accurate time signal received from WWV to trim the crystal oscillator. The timekeeping between updates was thus considerably more accurate than the crystal alone could have achieved. Time down to the tenth of a second was shown on an [[LED]] display. The GC-1000 originally sold for US$250 in kit form and US$400 preassembled, and was considered impressive at the time. Heath Company was granted a [http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=4582434.PN.&OS=PN/4582434&RS=PN/4582434 patent] for its design.<ref>{{cite web |title=Heathkit GC-1000-H Most Accurate Clock |url=https://www.pestingers.net/pages-images/heathkit/radio-equipment/gc1000/gc1000.htm |website=Pestingers |archive-url=https://web.archive.org/web/20200214054036/https://www.pestingers.net/pages-images/heathkit/radio-equipment/gc1000/gc1000.htm |archive-date=February 14, 2020 |url-status=live}}</ref><ref>{{US patent reference |number = 4582434 |issue-date = April 15, 1986 |inventor = David Plangger and Wayne K. Wilson, Heath Company |title = Time corrected, continuously updated clock}}</ref>

By 1990, engineers from German watchmaker [[Junghans]] had miniaturized this technology to fit into the case of a digital wristwatch. The following year the analog version [[Junghans Mega|Junghans MEGA]] with hands was launched.

In the 2000s (decade) radio-based "atomic clocks" became common in retail stores; as of 2010 prices start at around US$15 in many countries.<ref>[http://www.kleenezeshop.com/products/2988-radio-controlled-clock.aspx/?affiliateid=779" Radio controlled clock £19.95] {{webarchive|url=https://archive.today/20130216084404/http://www.kleenezeshop.com/products/2988-radio-controlled-clock.aspx/?affiliateid=779 |date=2013-02-16}}</ref> Clocks may have other features such as indoor thermometers and [[weather station]] functionality. These use signals transmitted by the appropriate transmitter for the country in which they are to be used. Depending upon signal strength they may require placement in a location with a relatively unobstructed path to the transmitter and need fair to good atmospheric conditions to successfully update the time. Inexpensive clocks keep track of the time between updates, or in their absence, with a non-disciplined [[quartz-crystal clock]], with the accuracy typical of non-radio-controlled quartz timepieces. Some clocks include indicators to alert users to possible inaccuracy when synchronization has not been recently successful.

The United States [[National Institute of Standards and Technology]] (NIST) has published guidelines recommending that radio clock movements keep time between synchronizations to within ±0.5 seconds to keep time correct when rounded to the nearest second.<ref name="lombardi2" >[https://tf.nist.gov/general/pdf/2429.pdf "How Accurate is a Radio Controlled Clock?"] by Michael Lombardi (2010).</ref> Some of these movements can keep time between synchronizations to within ±0.2 seconds by synchronizing more than once spread over a day.<ref>[https://cdn.nedis.com/datasheets/MAN_HE-CLOCK-89_EN.PDF RADIO-CONTROLLED WALLCLOCK INSTRUCTION MANUAL]</ref>

Timepieces with [[Bluetooth]] radio support, ranging from watches with basic control of functionality via a [[mobile app]] to full [[smartwatch]]es<ref>{{cite web | title=Bluetooth| publisher=Casio| url=https://www.casio.com/europe/watches/technology/bluetooth/ | access-date=16 July 2024}}</ref> obtain time information from a connected [[Mobile phone|phone]], with no need to receive time signal broadcasts.