High Precision TimekeeperFeodosii Mikhailovich Fedchenko

High Precision TimekeeperFeodosii Mikhailovich Fedchenko, model AchF-3, No. 25, made at the All-Union Scientific Research Institute of Physicotechnical and Radiotechnical Measure-ments, USSR, in 1970.Exceptionally fine and very rare astronomical, constant pressure, isochronous suspension, temperature compen-sation, short central impulsing, battery powered, master pendulum observatory regulator beating seconds, with simple change from mean solar time to sidereal time, considered to be the world's most accurate pendulum clock, with an average accuracy of approximately 0,002 seconds per day. Cast-iron bracket supporting constant pressure steel cylinder with heavy bell glass jars at the top and bottom, fastened to a steel frame holding a steel bar with the dial on the right, small bracket at the back for the mercury oxide battery of capacity 2.5 amp hour providing power for over 3 years of continuous working, and electronic control unit. White with tapered indexes and fifteen-minute Arabic markers. Sharp point tapered hands. Consists of 10 kilogram invar pendulum with 2 secods period, its suspension, electro-magnetic impulse delivery device, pressure controlling baroscope, microscope for amplitude checking, battery power module and secondary clock system with its own battery, switching from mean time to sidereal time by moving a small weight in the pendulum.Signed on front at the suspension.Dim. Height 1,5 meter. Notes Model AchF-3 is the most accurate pendulum clock in th Read more…