Beta (time signal)
Beta is a time signal service in the VLF range in Russia, operated by the Russian Navy. It is controlled by All-Russian Scientific Research Institute for Physical-Engineering and Radiotechnical Metrology. 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 time scale. No time code is sent during the last quarter of an hour.
The Beta network
Beta consists of the following transmitters:Callsign | Transmitter Location | 20.5 kHz | 23.0 kHz | 25.0 kHz | 25.1 kHz | 25.5 kHz | Map Link |
RJH69 | Vileyka VLF transmitter near Molodechno | x | x | x | x | x | |
RJH77 | Archangelsk | x | x | x | x | x | |
RJH63 | Krasnodar | x | x | x | x | x | |
RJH90 | Nizhny Novgorod | x | x | x | x | x | |
RJH86 | Bishkek | x | x | x | x | x | |
RAB99 | Khabarovsk | x | x | x | x | x |
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 kW, achieving 30–50 kW EIRP.
The time code consists of a series of carrier pulses:
- 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
Most of the stations were built in the 1970s. RJH63 and RAB99, built later, has a different transmission: