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GPS to Radio-controlled Atomic Clock

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GPS to Radio-controlled Atomic Clock

By hyiu00
-  Fri Sep 27, 2013 3:37 pm #163939
The purpose of this simple DIY project is to build an electronic circuit that received the GPS time signal, convert it to the radio-controlled clock format, and transmit that signal to the clock. Once built, there is no need for setup and maintenance, all you need is put this unit close to the window to receive GPS signal, and it will transmit the time signal to your radio-controlled clock.

http://sourceforge.net/projects/gpstora ... lledclock/

Image

Re: GPS to Radio-controlled Atomic Clock

By hyiu00
-  Tue Oct 01, 2013 5:57 pm #164069
fkatzenb wrote:
waltr wrote:And is it LEGAL to transmit on the WWVB frequency? I doubt it.
correct. Illegal
This is why I deliberately make the output very low power. The wire loop "antenna" has a Q of less than one. It is actually coupling magnetic field to the clock instead, so it is more like a transformer than an antenna. The tested range is only three feet. Therefore, to use this design, it is recommended to put the wire loop close to the clock.

Re: GPS to Radio-controlled Atomic Clock

By hyiu00
-  Tue Oct 01, 2013 6:41 pm #164071
fll-freak wrote:Just be aware that GPS and UTC time are not the same. They differ by a ever changing number of seconds.
Yes, based on "u-blox 6 Receiver Description Including Protocol Specification", the GPS module default time pulse (UBX-CFG-TP) is using GPS time instead of UTC time. But the NMEA RMC message content is still outputing UTC time. Therefore, the worse case is that this design will miss by a maximum of 1 second. Since the message reporting rate is also controlled by the GPS time, there will be no timing problem between the 1PPS signal (generated by GPS time) and the RMC message output rate (also generated by GPS time).

Re: GPS to Radio-controlled Atomic Clock

By nigelmercier
-  Sat May 17, 2014 3:11 am #171217
I've got a similar device that creates a 5V modulated carrier at 60kHz, to simulate MSF. I want to be able to receive it about 5 metres away, so it will set my radio controlled clocks. It's called a Chronvertor, I was going to build my own, but at £15 it isn't worth it

It has been suggested that a ferrite antenna from a LW radio with a suitable capacitor could form a tuned circuit, but I'm not sure of values, or how to drive it.

Note: this is operating a couple of thousand miles from MSF
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