RBU is a time code radio station located in Moscow (56°44′00″N 37°39′48″E / 56.73333°N 37.66333°E).[1] It transmits a continuous 10 kW time code on 66⅔ kHz.[2] This is commonly written as 66.66[1] or 66.666 kHz,[3] but is actually 200/3 kHz.[2] Until 2008, the transmitter site was near Kupavna 55°44′04″N 38°9′0″E / 55.73444°N 38.15000°E and used as antenna three T-antennas spun between three 150 metres tall grounded masts. In 2008, it has been transferred to the Taldom transmitter at 56°44′00″N 37°39′48″E / 56.73333°N 37.66333°E.[4]
RBU is controlled by All-Russian Scientific Research Institute for Physical-Engineering and Radiotechnical Metrology. It is operated by Russian Television and Radio Broadcasting Network.[5]