The radio signal, for clocks that can listen for it and set the time, has it been offline today?
People call it the Rugby signal because it used to be transmitted from there, but I think now it's transmitted from somewhere in Cumbria.
Unplugged a radio signal clock from the mains today and it took several huors before it synced to the signal.
Yes:
Peter
En el artículo , Peter Andrews escribió:
Fantastic, thank you.
What are the purposes of the time transmissions on the short wave bands. They appear to be bleeps but near minuits and hours one can hear data and even voices on some of them. 5Mhz etc. Brian
Wide area frequency standards, the carriers are very accurate. Also wide area coverage of accurate time information.
"fast code" in MSF speak, though I think they have dropped that these days, the "slow code" is easier to decode and less susceptable to noise.
Can't find the same information on the NPL site but that is a nice mainly text page. 2 bits/second indicated by the duration the carrier is off each second.
Some legistures require a regular voice identification of the signal.
Hello,
Are there any kits to DIY your own clock? Maplin used to do one a long, long time ago but I've not seen anything since.
Thanks, Stephen.
This will give you the front end:
decoding and display I leave up to you to find :)
GIYF
Cheap MSF clock from the likes of a pound shop or Lidl etc?
Ardino or Raspberry will decode without breaking sweat, I suspect a PIC could do it. The display is probably the hardest bit.
I still have the Maplin kit (not in use). I had it on a system running Interactive UNIX in the early 1990's, and wrote a driver to decode the signal and synchronise the system.
During the period of debugging it, I could easily tell the time just by listening to the carrier (shifted to audio frequency) - it's easy to decode by ear. It spends most of the minute transmitting what the time will be at the next minute boundary, at 1 bit/second. I didn't decode the fastcode (encoding the date/time quickly in the
59th second), but it was subsequently removed from the signal anyway. I did sit and listen to it through the GMT/BST changes - IIRC, it starts sending a warning bit for an hour beforehand that the clocks are about to change.Have something to add? Share your thoughts — no account required.
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