Hi everyone,
Facing issues with catching the DCF77 signal (time) with two Radio controlled clock movement, I bought a DCF77 receiving module and I would like to create a kind of autonomous DCF77 amplifier.
Not knowing the possibilities of Arduino, I am questioning myself about the possibilities of building such a setup or even emulating the DCF77 signal from scratch.
Any advice iswelcomed 
Will,
Hello GLDDD, welcome to the forum.
I've read your post several times but cannot work out what you want to know. What is an
autonomous DCF77 amplifier
?
Or an
autonomous emitter
?
The terminology used for radio equipment is usually transmitter and receiver.
I have a working MSF (60kHz) clock built around a similar module and using a PIC to decode the time signal. Doing the same with and Arduino should be simple enough.
GLDDD:
…
Not knowing the possibilities of Arduino, I am questioning myself about the possibilities of building such a setup or even emulating the DCF77 signal from scratch.
Those tiny signals are elusive. You could probably spend more on a better receiver.
But I do know you can emulate the DCF77. I can’t find it now googling (more like it is your trip not mine) but I purchased a small module that does just that. It has an RTC and a microprocessor and its output works as the DCF77 signal.
The protocol is fairly straight ahead and completely documented. If you can’t find/don’t want to buy a cheap module, it should be easy enough to synthesize.
edit: found it IRL, and found it online at https://unusualelectronics.co.uk/chronvertor2/ now new and improved.
a7
Dcf77 generator:
I wonder about the consequences if a third party emits its own DCF77 signal, preventing all receivers in an unspecified neighbourhood from receiving the original signal.
I suppose the OP is looking to build a low power local repeater. The DCF77 transmitter near Frankfurt has a power of 50kW, but even a few watts might be enough to create havoc in a small area, particularly if it was transmitting incorrect times. The legal consequences of getting caught would depend on local laws.
I have used the blinkenlight dcf generator for testing a dcf receiver when I was experimenting with different ferrite rod antennas and the power when following the instructions would affect clocks within about 50cm only.
I suppose the OP is looking to build a low power local repeater.
I wondered that after I made my original reply. Maybe he will tell us.
Hi,
I think I have similar need.
My receivers are not able to get DCF77 signal in my home (they work in other location).
I would like to use something like D1 mini wifi ESP8266 to get time from NTP and convert it into DCF77 signal.
I had some devices with DCF receiver and would like to keep them in house.
I have some doubts about antenna. I read a little bit and have an overview like 6v6gt wrote: range is about 50cm and I would like to have range about 10m (will be grate).
For now I had only idea like:
NTP server - some module (ESP8266/Raspberry Pi/something else) - antenna - my receivers.
It will be good to have possibility connect via WI-FI to home network and have possibility to place it into central place without cables.
I'm not sure esp8266 can generate the required frequency, but Rasp Pi can.
Check the above there is the solution. The only thing is antenna/amplifier for 10m