Greenwich Time Signal Greenwich Time Signal The Greenwich Time Signal (GTS), popularly known as the pips, is a series of six short tones broadcast at one-second intervals by many BBC Radio stations. The pips were introduced in 1924 and have been generated by the BBC since 1990 to mark the precise start of each hour. Their utility in calibration is diminishing as digital broadcasting entails time lags. There are six pips (short beeps) in total, which occur on each of the 5 seconds leading up to the hour and on the hour itself. Each pip is a 1 kHz tone (about halfway between
Manana Island Sound Signal Station the trumpet was moved to the Portland Head Light. Originally administratively part of Monhegan Island Light, the fog signal was placed under separate administration in 1876. In 1877 a new Daboll trumpet was installed. It was replaced in 1912 by an air siren, and at some point a radio beacon was added to the site. The station was automated in 1986, and the radio tower was removed in 1995. Manana Island Sound Signal Station The Manana Island Sound Signal Station is an active fog signal station on Manana Island, Maine, United States. Established in 1855, it is one of the