DCF-77 receiver, any ideas?
 

Hi,

After getting hold of some nixie tubes, I've built myself an alarm clock
using four tubes to show hh:mm (or dd:mm, at the press of a button).

I am now thinking of extending its functionality; rather than keeping
track of time using a RTC module, I'd like it to set itself after the
DCF77 German LW time signal station.

The format is quite simple - AM, carrier drops to 25% power for a period
of .1 or .2 seconds at the beginning of each second, symbolising a logic
low or high, respectively. The date, time and other info is then encoded
in a datagram whose transmission takes a minute.

My first idea is to build a direct conversion receiver, using a micro-
controller with ADC to decode the data stream.

Any other suggestions? Seems DC will get me going with a minimum of
parts - all of which I have in my junk box. Any reasons why this might
not work satisfactorily? I live on 63'40"N, so the signals are not very
strong - my Junghans DCF77 controlled alarm clock works fine in winter,
less so in summer. I will be using a much larger ferrite for antenna in
the nixie clock, though. Sensitivity shouldn't be a problem.

Thanks,

--
73 de LB1LF

Odd Erling, ARK

More people are killed by donkeys than plane crashes.