RADIO CLOCK

The time signal transmitted from Rugby in England on 60kHz delivers the date and time at a rate of 1 bit per second. It can be received by an active antenna and used to accurately set the clock on a TDS2020F. Portable applications will always show the correct time, unaffected by crystal oscillator drift.

Radio clock

Although the transmitter is in central England, reliable operation has been reported from as far away as Finland. The active antenna size is 120 x 29 x 19mm and the order code is RADIOCLOCK-UK.

The time will be automatically adjusted for daylight saving twice a year. Operation is entirely under interrupt so the foreground program is free for other operations such as data logging.

Connection to the TDS2020F is at one parallel port pin and it has two wires for the power supply. The library routine #TIMEUK.TDS (comes with the Update Service) has all the details. This software receives the signal using an interrupt every 12.5ms, verifies it, decodes date and time and sets the board clock each minute. Typically 3 to 6 minutes are needed after power-up for synchronisation and first setting of the clock.