A proof-of-concept
DCF77
time signal simulator written in JavaScript, using Web Audio API. You
can use this web page to synchronize your DCF77-radio-controlled clock
or watch. Click on START TRANSMISSION, set your radio
controlled clock or watch to “receive” mode and place it near a
speaker or a pair of headphones. It should take a few minutes at most
for your watch to synchronize. If you cannot get it to work, try
increasing the volume.
The transmitted signal is automatically in
timezone (DCF77 signal time).
Some filtering has been applied to the signal to make it less harsh on
ears and to improve the signal quality. Nevertheless, the signal is a
high-pitched 15.5kHz sine wave, so please
protect your hearing and do not start the transmission with full
volume! The signal has been successfully tested on a Casio Wave Ceptor
watch and a radio controlled wall clock. The best results were had
with an iPhone speaker, or a pair of headphones (most headphone brands
should work), with volume set to about 80–100%.