OMA (time signal) - Wikipedia

OMA was the callsign of a Czech time signal station. The station was operated by the Astronomical Institute of Prague and the transmitters were located at RKS Liblice 1.

The station transmitted in the LF band on 50 kHz with a power of 7 kW and in the HF band on 2500 kHz with 1 kW.^[1] A reserve LF transmitter was located at Poděbrady.

OMA, which could be also used for synchronizing radio controlled clocks, was shut down in 1995.

OMA time signal transmitter was used to synchronize radio clock. The transmit time protocol was changed multiple times. Periodic service maintenance outages lasted for days. The decoding was done in discrete hardware. Commercial use of OMA time signal was limited by absence of highly integrated receiver and decoding chip.

OMA was synchronized by Cesium Reference clock run by CSAV Czech Academy of Sciences, Kobylisy, Prague. Limited series of secondary 5MHz references with thermostat were manufactured by the institute. The secondary reference employed single transistor crystal oscillator with XF filter. The institute was under keen eye of communist party, dictating the R&D direction. They had there their devoted people. TV broadcasting and high reliability services were synchronized from the Cesium Reference. Today (2020) there are calls to resurrect the transmitter for resilience case. Performance of WWV beacon confirms the importance.

References

^ Gerd Klawitter (1980). List of Time Signal Stations (9th ed.).

External links

v t e Time signal stations
Longwave	BPC BPL BSF Beta DCF77 JJY RBU RTZ TDF time signal Time from NPL WWVB
Shortwave	BPM CHU HD2IOA HLA JN53DV ROA Time RWM WWV WWVH YVTO
VHF/FM/UHF	Radio Data System
Satellite	BeiDou DORIS GLONASS Galileo Global Positioning System IRNSS Quasi-Zenith Satellite System
Defunct	BSF HBG NAA OLB5 OMA Radio VNG WWVL Y3S

Time

Key concepts

Measurement
and standards

Chronometry	UTC UT TAI Unit of time Orders of magnitude (time)
Measurement systems	Italian six-hour clock Thai six-hour clock 12-hour clock 24-hour clock Relative hour Daylight saving time Chinese Decimal Hexadecimal Hindu Metric Roman Sidereal Solar Time zone
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Philosophy of time

Human experience
and use of time

Time in science

Geology	Geological time age chron eon epoch era period Geochronology Geological history of Earth
Physics	Absolute space and time Arrow of time Chronon Coordinate time Instant Proper time Spacetime Theory of relativity Time domain Time translation symmetry Time reversal symmetry
Other fields	Chronological dating Chronobiology Circadian rhythms Clock reaction Glottochronology Time geography

v t e Time measurement and standards
Chronometry Orders of magnitude Metrology
International standards	Coordinated Universal Time offset UT ΔT DUT1 International Earth Rotation and Reference Systems Service ISO 31-1 ISO 8601 International Atomic Time 12-hour clock 24-hour clock Barycentric Coordinate Time Barycentric Dynamical Time Civil time Daylight saving time Geocentric Coordinate Time International Date Line IERS Reference Meridian Leap second Solar time Terrestrial Time Time zone 180th meridian
Obsolete standards	Ephemeris time Greenwich Mean Time Prime meridian
Time in physics	Absolute space and time Spacetime Chronon Continuous signal Coordinate time Cosmological decade Discrete time and continuous time Proper time Theory of relativity Time dilation Gravitational time dilation Time domain Time-translation symmetry T-symmetry
Horology	Clock Astrarium Atomic clock Complication History of timekeeping devices Hourglass Marine chronometer Marine sandglass Radio clock Watch stopwatch Water clock Sundial Dialing scales Equation of time History of sundials Sundial markup schema
Calendar	Gregorian Hebrew Hindu Holocene Islamic (lunar Hijri) Julian Solar Hijri Astronomical Dominical letter Epact Equinox Intercalation Julian day Leap year Lunar Lunisolar Solar Solstice Tropical year Weekday determination Weekday names
Archaeology and geology	Chronological dating Geologic time scale International Commission on Stratigraphy
Astronomical chronology	Galactic year Nuclear timescale Precession Sidereal time
Other units of time	Instant Flick Shake Jiffy Second Minute Moment Hour Day Week Fortnight Month Year Olympiad Lustrum Decade Century Saeculum Millennium
Related topics	Chronology Duration music Mental chronometry Decimal time Metric time System time Time metrology Time value of money Timekeeper

50°04′22″N 14°52′47″E / 50.0728°N 14.8797°E / 50.0728; 14.8797