I'm using this module.
http://www.pvelectronics.co.uk/rftime/SYM-RFT-XX.pdf
Output should be inverted as far as I know after reading the manual.
I'm not getting any time by using the arduino-library for dcf77.
The LED on the device is blinking some kind of nervous.
On youtube I saw that the signal-impulse of the LED should be every 5 seconds...