In the past, time and frequency transmission via LORAN and via synchronization pulses in television signals played an important role. The importance of LORAN for navigation on sea disappeared with the advent of GPS. Most recently, the operation of the LORAN transmitter Sylt was financed by a contract with Trinity House in their capacity as General Lighthouse Authority of the United Kingdom. However, the British LORAN transmitters were also switched off at the end of 2015, after this step had already been taken for French and Norwegian stations. As a result, the Sylt station is also currently unusable.
For many years, in particular after the German Unification, frequency comparisons with UTC(PTB) via the image synchronization pulses in the TV signals of the ZDF (Second German Television Channel) have been important to maintain the industry’s measurement infrastructure in the new federal states. In the technical centre of the ZDF, the colour carrier and the synchronous pulses contained in the television signal have been (and still are) de-rived from a rubidium frequency standard whose output frequency has been controlled by comparison with the received DCF77 carrier frequency - with the frequency of UTC(PTB) with a relative uncertainty of less than 1.10-11. As a result of the current practice of digital transmission of the TV signal between individual production sites, the central transmitting studio and the partially digital emission, the propagation times on these transmission paths no longer show constant values or only monotonously changing ones. This is why the procedure of the TV frequency comparisons has become irrelevant, and PTB no longer provides any relevant data.
The digital terrestrial television reception, which is gradually being extended in Germany, does not even allow the correct time to be transmitted to the spectators: The television pictures are displayed on the TV screen with a delay of up to several seconds.