(Exact Pendulum Beacon)
- The Czech time radiobeacon driven by pendulum
- The time signal of OK0EPB is generated by a pendulum with a rod made of fused quartz.
- The clock's machine works on the basis of Froment's system with a constant impulse. (take a look here)
- The maximum difference of time signal is held in the tolerance of 0.1 sec.
- The beacon output power of TX is 10 (ten) W to dipole @22m.
Beacon transmiting dots every seconds, without transmiting call, foF2 index and time number. In full minute transmit dash after three dots.
Pendulum is enclosed in a vacuum chamber (by www.vakuum.cz) to avoid the impact of changes in atmospheric pressure. Infra red sensor detected position of pendulum. Software measured and evaluated gearing a la Froment electrics system
Earthquake 14. Aug 2012(Edit)
in sea of Okhotsk (49.784°N, 145.126°E) with [magnitude 7,7 http://earthquake.usgs.gov/earthquakes/recenteqsww/Quakes/usc000bz29.php]
Seismogram from Prague
Dependence frequency error on air pressure(Edit)
between 15 and 21 Dec 2011
Results of G3PLX measurement at 12/13 Dec 2011(Edit)
Here attached is a good record from last night. The channel was clear of the Sura ionospheric radar which has been there for a week or so. This shows two shift pulse events, with the pendulum running about +3ppm between them. The 60mS point on my graph is the same point as the 0 mS point on your Phase graph. The 60mS difference is made from (1) 50mS because you measure the start of the dot and I measure the centre, (2) 4mS because I am 1200km from Prague, and (3) 6mS which we think may be the key-click filter in your transmitter.
- Frantisek OK1DF - Founder and the mastermind
- Petr ex OK1IRG - Software developer
- Jan OK2ZAW - Beacon hardware
- Peter G3PLX - Invaluable assistance
- Dan OK1HRA - It & webmaster