11. In 1977, the current phase modulated time signal was added to the transmissions. 12. These public time signals were formerly established in many seaport cities. 13. The official time signal is given by the Time and Frequency Standards Laboratory. 14. The Bureau des Longitudes started daily time signal service starting in May 1910. 15. Vancouver radio station CKNW also broadcasts time signals , using a chime every half-hour. 16. These are used to generate timing signals for the downlink of science data. 17. Dually, a discrete-time signal gives rise to a periodic frequency spectrum. 18. Initially he broadcast time signals to Allegheny city business and the Pennsylvania Railroad. 19. All chronometers and watches should be checked regularly with a radio time signal . 20. The station has a long history of a powerful night-time signal .
