After last month’s Lighthouses experiment I am back on track with my DCF77 clock. The Second Decoder is now extended with additinal decoders for decoding time data.
From the architecture point of view this adds just two more boxes.
But don’t be fooled. These two boxes have a quite different construction from the second decoder. The other decoder boxes that are still missing will rely on the same inner workings. All of them will utilize a hamming metric based approach.
The software part of the project is getting closer to its final stage:
- Exponential filtering of the signal
- Phase locked loop / optimal filter for 1Hz phase reconstruction
- Reconstruction of the seconds
- Hamming metric based reconstruction of the data
- Dealing with signal loss
Finally my clock can decode the current time . So next month I can take care of the date 😉
With regard to the antenna hardware I finished reading the books:
Das neue Magnetantennenbuch: Selbstbau-Loops für Sende- und Empfangsbetrieb
Außergewöhnliche Empfangsantennen und ihre Anpassung für den Längst- und Kurzwellenbereich
Since this created a desire for more I started to read this one as well:
My summary so far:
- The best amplifier is a better antenna.
- Bigger is better.
- There is more to learn about antennas than you might expect.