Testing CMA-77-100 antenna with SYM-RFT-77 DCF77 receiver module
Michail Papadimitriou is in the process of developing a Nixie clock which will synchronize with the DCF77 time signal. These standard time signals are transmitted on 77.5 kHz from Germany, and Michail intends to use a DCF77 Time Receiver Module, like SYM-RFT-77 to demodulate the signal. Basically, this module receives the time standard signal and outputs a high pulse at precise one second intervals. The trick is being able to receive the VLF signal with sufficient strength and clarity to be read by the module. Michail experimented with various 77.5 kHz antennas and wrote this small review about testing the CMA-77-100 antenna with the SYM-RFT-77 DCF77 receiver module.
(If you’re really into antenna design for DCF77, check out this explanation of VLF antenna design theory from C-MAX time solutions, manufacturers of the CMA-77-100 antenna.)
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Comments
Still wondering if this is possible without the ‘gop’ and can be done with one of the avr/pic pins.
The latest Elektor has an article on dcf77 signal generation as part of their sdr with avr series. Haven’t had a chance to get to it yet (still deciding if I want to spend 100+€ on the HW) but the article should be up on their website.
but that’s Generation. I can’t imagine that it’s not possible via the ADC pin on our micro or with some parts on a digital pin even! Loads and loads of examples to decode various ‘blobs’ like the one above. But having to need only an antenna and maybe a crystal and some caps on an 6pin attiny would be cool.
I checked out the article a bit further and they explain both signal generation using an attiny and signal reception using an atmega chip. The latest article can be found here: http://www.elektor.com/100182 (in German: http://www.elektor.de/100182 and French: http://www.elektor.fr/100182 etc.).