Time and Frequency Dissemination System of Moderate Accuracy, Sophistication and Cost

Abstract

LF time signals are a convenient means to disseminate time and frequency over a range of the order of 2000 km. Because the waves at frequencies below 100 kHz penetrate easily into buildings, the antenna can be incorporated into the receiver. The reception being very reliable, it is easy to build clocks which are continuously synchronized. At LF frequencies receivers can be built with very low power consumption, so that a complete synchronized clock can be powered by one single Lithium cell for 10 years. If, moreover, the clocks can be manufactured in reasonable quantities, the resulting price is moderate.

Nevertheless, capital and operating costs for LF-transmitters are high. The time service of Switzerland has therefore decided to combine the time signals of its transmitter HBG with an emergency call or paging system, compatible with all uses of time signals. It is anticipated that this paging system will cover most, if not all, the costs of the transmitter.

In regions where no LF time signals are available, Omega signals are a useful substitute. Our experience with these signals will be reported.