DF1UD EN

DCF 77 is a time signal and is transmitted in Europe with normal frequency of 77,5 kHz as time information in coded form. The amplifier power output is approx. 50 kW and the antenna power is approx. 30 kW with a coverage of approx. 2000 km in a circumference at Frankfurt/main (Mainflingen).

Year of built 1984

The clock worked in a commercial housing with self-designed front panel. Seen as a "Base" is in the picture, the connected by cable with active wound ferrite rod antenna and amplifier.

The "IC-Heater"

The many TTL IC's and integrated power supply with two transformers in this unit was much useless power generated as heat (unfortunately). In some cases I was able to counteract this heat through the use of TTL IC's, the LS series, but it still flowed out some amps from the power supply.


Now to the actual construction

Unfortunately, 'accidentally spill gone' all my documents to the spring cleaning of the basement. I can only write down from memory a few comments on this project.
Started this project late 70s with colleagues of my company. Somewhere the Dekodierschema published DCF-77 transmitter Mainflingen. It was debated and discussed. Then, finally, were the joint recipients, and developed with the digital decoding of the signal and plotted in various layouts. Thus arose in the end nothing unique, because each of the devices had built a different appearance in the form of printed circuit boards, wiring and housing etc.

The technical details of the time signal transmission of DCF-77 can be found here, among other things.

• Building on some with-designed PCB layout and prototyping boards.
• Wiring with copper magnet wire and insulated wire circuit.
• If possible, the compounds of the boards were each pluggable.

Top