DCF77 Time Signal Generator with ESP32 (classic)

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Expand view Topic review: DCF77 Time Signal Generator with ESP32 (classic)

Re: DCF77 Time Signal Generator with ESP32 (classic)

by PeterN » Mon Nov 18, 2024 8:31 am

[Local Link Removed for Guests] wrote: [Local Link Removed for Guests]Mon Nov 18, 2024 7:55 am That was me. I needed something with a bit more height to support the base loaded 1/4 wave antenna.
Managed to find a suitable PSU too.
This fits in very well with my plans, as I am currently converting from a magnetic field to an electric field. I just need to scale it up a bit.
IMG_7337.jpeg

Re: DCF77 Time Signal Generator with ESP32 (classic)

by BeanieBots » Mon Nov 18, 2024 7:55 am

[Local Link Removed for Guests] wrote: [Local Link Removed for Guests]Sun Nov 17, 2024 10:36 am Take a look North-North-East. I have heard BigBen doing strange things
That was me. I needed something with a bit more height to support the base loaded 1/4 wave antenna.
Managed to find a suitable PSU too.

Re: DCF77 Time Signal Generator with ESP32 (classic)

by PeterN » Sun Nov 17, 2024 10:36 am

[Local Link Removed for Guests] wrote: [Local Link Removed for Guests]Sun Nov 17, 2024 10:32 am
[Local Link Removed for Guests] wrote: [Local Link Removed for Guests]Sat Nov 16, 2024 6:02 pm .... When I saw the frequency response of a 2€ LM386 amplifier board today, I had a terrible idea, but only for a very short fleeting moment ;-)....
Go on, you know you want to. I won't tell anyone. I'll be keeping an eye on my clocks though ;)
Take a look North-North-East. I have heard BigBen doing strange things

Re: DCF77 Time Signal Generator with ESP32 (classic)

by BeanieBots » Sun Nov 17, 2024 10:32 am

[Local Link Removed for Guests] wrote: [Local Link Removed for Guests]Sat Nov 16, 2024 6:02 pm .... When I saw the frequency response of a 2€ LM386 amplifier board today, I had a terrible idea, but only for a very short fleeting moment ;-)....
Go on, you know you want to. I won't tell anyone. I'll be keeping an eye on my clocks though ;)

Re: DCF77 Time Signal Generator with ESP32 (classic)

by Electroguard » Sat Nov 16, 2024 8:33 pm

A good idea, I will give that a try.

Re: DCF77 Time Signal Generator with ESP32 (classic)

by PeterN » Sat Nov 16, 2024 8:06 pm

Perhaps you have an old ferrite rod from an AM radio lying around? Take it with the original winding and position it as close as possible PARALLEL to the clock's rod antenna. That should do the job perfectly

Re: DCF77 Time Signal Generator with ESP32 (classic)

by Electroguard » Sat Nov 16, 2024 7:51 pm

Well, the fact that I had to ask proves that you made a good job of it.
Rather than convince my wife to take up embroidery, I've had a better idea... build the loop aerial actually inside the housing of my round wall-hanging clock. The small radio clock module in the middle is not accessible, but if surrounded by the loop aerial it should receive a good non-contact signal - and doesn't even need to look good, I could simply hot glue the wire loop inside the case.

Re: DCF77 Time Signal Generator with ESP32 (classic)

by PeterN » Sat Nov 16, 2024 6:02 pm

[Local Link Removed for Guests] wrote: [Local Link Removed for Guests]Sat Nov 16, 2024 5:49 pm That last picture looks with the loop looks like it could suit my needs Peter, did you buy the loop antenna or make it yourself ?
DIY, Robin !
This is an embroidery hoop which I cruelly kidnapped from my wife , with 6 turns of flat computer cable and 300nF in parallel. My NanoVNA says that it resonates at 75kHz.
This was a good way to test with different clocks.
If you manage to twist a few turns around the original ferrite rod - this is the most reliable wireless way.

EDIT: The frame has a diameter of 21cm, 6 turns, 300nF; connected via 100Ohm between pin25 and GND. When I saw the frequency response of a 2€ LM386 amplifier board today, I had a terrible idea, but only for a very short fleeting moment ;-)

Re: DCF77 Time Signal Generator with ESP32 (classic)

by Electroguard » Sat Nov 16, 2024 5:49 pm

That last picture looks with the loop looks like it could suit my needs Peter, did you buy the loop antenna or make it yourself ?

Re: DCF77 Time Signal Generator with ESP32 (classic)

by PeterN » Sat Nov 16, 2024 2:59 pm

I have made a few small changes that make it very easy to connect the DCF77 time signal generator to almost any type of DCF77 radio-controlled clock.
If space in the clock is limited, you could think about using an M5 ATOM lite in its cute case and pin25 as output.
IMG_8586.jpeg

A more elaborated description can be found at https://peterneufeld.wordpress.com/2024 ... generator/


EDIT: One of my test scenarios with a separate magnetic loop resonant circuit

IMG_7332.jpeg

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