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MSP430_radio_clock

This is just a project idea, I've not tried building this - yet.
 
A software defined VLF radio receiver to receive and decode the NPL time signal transmitted from Anthorn.  See http://en.wikipedia.org/wiki/Time_from_NPL for more information on the transmission - previously known as "Rugby MSF".
 

Concept

Use very few RF components, perhaps just a ferrite rod antenna, fixed capacitor and single transistor amplifier and/oscillator.
Demodulate (data is BCD). Use clock crystal to provide backup time source if signal is lost.  Use attractive salvaged display, nixie or vacuum fluorescent display (VFD) ex-VCR, or maybe a stepper motor to create something like those old mechanical digital "flip" clocks
There's a nice mention here http://en.wikipedia.org/wiki/Split_flap_display of generating a flapping noise to indicate a change.  This could be applied to a VFD or nixie clock.
 

Alternatives

From time to time Lidl sell a range of cheap "radio controlled" clocks and "weather stations". I bought a 4-LD1558 for £15.
Interestingly the DCF77 receiver isn't built into the display, but instead is part of the external temperature and humidity sensor which sends data to the display every few minutes via 433MHz radio signals.
 
 
 
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