Editing Beta (time signal)

{{Short description|Time signal radio station in Russia}}
'''Beta''' is a [[time signal service]] in the [[Very low frequency|VLF]] range in [[Russia]], operated by the [[Russian Navy]].<ref name="c3systems">[http://www.astrosol.ch/networksofthecisforces/vlfmorsedigmodenetwork/5379039f1707a4601/index.html C3 Systems of the CIS Navy] {{webarchive |url=https://web.archive.org/web/20111005174016/http://www.astrosol.ch/networksofthecisforces/vlfmorsedigmodenetwork/5379039f1707a4601/index.html |date=October 5, 2011 }}</ref> It is controlled by [[All-Russian Scientific Research Institute for Physical-Engineering and Radiotechnical Metrology]].<ref name="vniiftri">{{Cite FTP |url=ftp://ftp.vniiftri.ru/BULLETINS/V/BulV_16_2018.pdf|lang=ru|format=PDF|script-title=ru:Эталонные сигналы частоты и времени|server=FTP server|url-status=dead|trans-title=Standard Time and Frequency Signals|access-date=2020-05-10}}. Official signal specification.</ref> There are 6 transmitter stations, which take turns transmitting time signals and other communications.

Each transmitter has 1 or 2 scheduled sessions per day lasting 31–41 minutes, depending on transmitter, total 8 sessions in 24 hours. Beginning on the hour is 15–20 minutes of 25.0 kHz, including [[morse code]] station identification and time code.  This is followed by 3- or 4-minute intervals of 25.1, 25.5, 23.0 and 20.5 kHz of unmodulated carrier precisely phase-locked to UTC(SU) time scale.  No time code is sent during the last quarter of an hour.<ref name="vniiftri"/>

== The Beta network ==
Beta consists of the following transmitters:<ref>{{cite book |author=Marten, Michael |title=Spezialfrequenzliste 2007/08, band&nbsp;2 |publisher=Siebel Verlag |language=de |isbn=978-3-88180-665-7 |year=2007 |page=36}}</ref><ref name="vniiftri"/>
{| class="wikitable"
|- 
! Callsign || Transmitter Location || 20.5 kHz || 23.0 kHz ||25.0 kHz || 25.1 kHz || 25.5 kHz || Coordinates
|-
| RJH63 || [[Krasnodar]]                     || x || x || x || x || x || {{coord|44.773537|N| 39.547241|E|type:landmark|name=RJH63}}
|-
| RJH69 || [[Vileyka VLF transmitter]] <!--
        -->near [[Molodechno]] ([[Belarus]]) || x || x || x || x || x || {{coord|54.462356|N| 26.769218|E|type:landmark|name=RJH69}}
|-
| RJH77 || [[Archangelsk]]                   || x || x || x || x || x || {{coord|64.360491|N| 41.568489|E|type:landmark|name=RJH77}}
|-
| RJH86<ref>in air RJH66</ref> || [[Bishkek]] ([[Kyrgyzstan]]) || x || x || x || x || x || {{coord|43.039444|N| 73.6125|E|type:landmark|name=RJH86}}
|-
| RJH90 || [[Nizhny Novgorod]] (former <!--
        -->German [[Goliath transmitter]])   || x || x || x || x || x || {{coord|56.171945|N| 43.931667|E|type:landmark|name=RJH90}}
|-
| RAB99 || [[Khabarovsk]]                    || x || x || x || x || x || {{coord|48.485550|N|134.823330|E|type:landmark|name=RAB99}}
|}
{{Location map+ |Russia    <!-- copied from [[Radio clock]] -->
|width          = 1000
|float          = none
|border         = 
|caption        = 
|alt            = 
|relief         = 
|AlternativeMap = 
|overlay_image  = 
|places         = 
 {{Location map~ |Russia |coordinates={{coord|44|46|25|N| 39|32|50|E}} |label=  RJH63   |position=right }}
 {{Location map~ |Russia |coordinates={{coord|54|27|47|N| 26|46|37|E}} |label=[[RJH69]] |position=bottom}}
 {{Location map~ |Russia |coordinates={{coord|64|21|29|N| 41|33|58|E}} |label=  RJH77   |position=bottom}}
 {{Location map~ |Russia |coordinates={{coord|43| 2|29|N| 73|37| 9|E}} |label=  RJH86   |position=top   }}
 {{Location map~ |Russia |coordinates={{coord|56|10|20|N| 43|55|38|E}} |label=  RJH90   |position=bottom}}
 {{Location map~ |Russia |coordinates={{coord|48|29|29|N|134|48|59|E}} |label=  RAB99   |position=top   }}
}}

== Frequency usage ==
The time code consists of a series of signals on multiple frequencies.  Transmission starts on the hour.  Each time a new frequency is selected, there is 1 minute of low power while the transmitter is adjusted, then full-power transmissions begin.

The transmitters are estimated to operate at 1000&nbsp;kW, achieving 30–50&nbsp;kW [[EIRP]].  (The difference is due to the low efficiency of antennas at this frequency, which must be much smaller than the 12&nbsp;km wavelength.)

{|class="wikitable" style="text-align:center"
|+Beta hourly transmission schedule<ref name="trond">[http://www.vlf.it/russianvlf/russianvlf.htm The Russian VLF time-signal stations, “Beta”], by Trond Jacobsen, with detailed transmission format information.</ref>
!rowspan=2| Frequency ||colspan=2|Minutes ||rowspan=2| Signal
|-
!Start || Duration
|-
|rowspan=7| 25.0 kHz
| :00 || 1 ||align=left| Transmitter tune-up, low-power unmodulated carrier
|-
| :01 || 5 ||align=left| Unmodulated carrier
|-
| :06 || 1 ||align=left| Morse code call sign, on-off keying
|-
| :07 || 3 ||align=left| Unmodulated carrier
|-
| :10 || 3 ||align=left| On-off modulated with 40 Hz square wave
|-
| :13 || 9 ||align=left| Time code, on-off modulation
|-
| :22 || 3 ||align=left| On-off modulated with 40 Hz square wave
|-
|rowspan=2| 25.1 kHz
| :25 || 1 ||align=left| Transmitter tune-up, low-power unmodulated carrier
|-
| :26 || 4 ||align=left| Unmodulated carrier
|-
|rowspan=2| 25.5 kHz
| :30 || 1 ||align=left| Transmitter tune-up, low-power unmodulated carrier
|-
| :31 || 4 ||align=left| Unmodulated carrier
|-
|rowspan=2| 23.0 kHz
| :35 || 1 ||align=left| Transmitter tune-up, low-power unmodulated carrier
|-
| :36 || 5 ||align=left| Unmodulated carrier
|-
|rowspan=2| 20.5 kHz
| :41 || 1 ||align=left| Transmitter tune-up, low-power unmodulated carrier
|-
| :42 || 5 ||align=left| Unmodulated carrier
|-
| Off
| :47 || ||align=left| Transmission ends
|}

The time code consists of a series of carrier pulses:<ref name="meinberg">[http://www.meinberg.de/english/glossary/r.htm Meinberg radio clock glossary: R], see entries for [http://www.meinberg.de/english/glossary/rab-99.htm RAB99], [http://www.meinberg.de/english/glossary/rjh-69.htm RJH69], [http://www.meinberg.de/english/glossary/rjh-77.htm RJH77], [http://www.meinberg.de/english/glossary/rjh-86.htm RJH86] and [http://www.meinberg.de/english/glossary/rjh-90.htm RJH90]</ref>
* Each 100 ms, a 25 ms burst of carrier is transmitted
* Each second, a 100 ms burst of carrier is transmitted
* Each 10 s, a 1 s burst of carrier is transmitted
* Each minute, a 10 s burst of carrier is transmitted
The hour or date is not coded.

Most of the stations were built in the 1970s.  RJH63 and RAB99, built later, has a different transmission:

{|class="wikitable" style="text-align:center"
|+RJH63 and RAB99 hourly transmission schedule<ref name="trond"/>
!rowspan=2| Frequency ||colspan=2|Minutes ||rowspan=2| Signal
|-
!Start || Duration
|-
|rowspan=6| 25.0 kHz
| :00 || 1 ||align=left| Transmitter tune-up, low-power unmodulated carrier
|-
| :01 || 5 ||align=left| Unmodulated carrier
|-
| :06 || 1 ||align=left| Morse code call sign, on-off keying
|-
| :07 || 2 ||align=left| Unmodulated carrier
|-
| :09 || 2 ||align=left| On-off modulated with 40 Hz square wave
|-
| :11 || 9 ||align=left| Time code, on-off modulation
|-
|rowspan=2| 25.1 kHz
| :20 || 2 ||align=left| Transmitter tune-up, low-power unmodulated carrier
|-
| :22 || 1 ||align=left| Unmodulated carrier
|-
|rowspan=2| 25.5 kHz
| :23 || 1 ||align=left| Transmitter tune-up, low-power unmodulated carrier
|-
| :24 || 2 ||align=left| Unmodulated carrier
|-
|rowspan=2| 23.0 kHz
| :26 || 1 ||align=left| Transmitter tune-up, low-power unmodulated carrier
|-
| :27 || 4 ||align=left| Unmodulated carrier
|-
|rowspan=3| 20.5 kHz
| :31 || 1 ||align=left| Transmitter tune-up, low-power unmodulated carrier
|-
| :32 || 4 ||align=left| Unmodulated carrier
|-
| :36 || 4 ||align=left| (RJH63 only) Digital data, ±50 Hz [[frequency-shift keying]], 50 [[baud]]<ref name="nils">[http://web.me.com/nils.schiffhauer/Website/Monitoring/Eintr%C3%A4ge/2011/7/11_Audio_Clips_-_Medium_Wave_%28%26_Longwave%29.html Nils Schiffhauer's medium/long-wave signa samples].  Particularly see the [http://web.me.com/nils.schiffhauer/Website/Monitoring/Eintr%C3%A4ge/2011/7/11_Audio_Clips_-_Medium_Wave_%28&_Longwave%29_files/RJH86FSK.jpg (frequency-shifted) transmission spectrum.] Horizontal divisions at 200 Hz show 100 Hz between frequencies.</ref>
|-
| Off
| :40 || ||align=left| Transmission ends
|}

==See also==
* [[RWM]]

==References==
{{reflist}}

==Further reading==
{{refbegin}}
* [http://www.vlf.it/trond2/20-25khz.html VLF radio networks information]
* [http://www.vlf.it/russianvlf/russianvlf.htm The Russian VLF time-signal stations, “Beta”], by Trond Jacobsen, with detailed transmission format information.
{{refend}}

[[Category:Time signal radio stations]]
[[Category:Science and technology in the Soviet Union]]
[[Category:Communications in the Soviet Union]]
[[Category:Soviet Navy]]
[[Category:Russian Navy]]

{{Time signal stations}}
{{Time signal authorities}}