In the UK (and much of europe), a broadcast time and frequency reference is available in the form of the MST radio time signal. This is broadcast using on-off keying on a frequency of 60 kilohertz, to within one part in 10^12.

I'd like to use this signal to construct a cheap and accurate 10MHz frequency reference. My tentative plan is to construct a PLL, with a VCTCXO as the VCO component, and lock it to the 60KHz reference. That's the easy part.

However, I'm not sure how to approach a couple of other aspects of the solution. Specifically:

  • What's the easiest way to receive and amplify the 60KHz carrier wave, producing a clean 60KHz square wave output from the receiver?
  • How should I handle the periods during which the transmitter is not sending the carrier wave (which can last up to 500ms, at the beginning of each minute)? I don't want the phase comparator to decide the clock is way out of phase and skew the TCXO frequency during this period.
  • \$\begingroup\$ Have you considered using GPS? U-blox make timing modules that pretty much do all of this for you. \$\endgroup\$ – Jon Jun 3 '15 at 10:07
  • \$\begingroup\$ @Jon I have, but I'd like it to work indoors, which is easy for MST, but not for GPS. \$\endgroup\$ – Nick Johnson Jun 3 '15 at 10:32
  • \$\begingroup\$ Farnell sell a 60kHz tuning fork crystal, if you want to try a crystal filter or a direct conversion receiver. I haven't found time to experiment with it myself. \$\endgroup\$ – Brian Drummond Jun 3 '15 at 12:16
  • \$\begingroup\$ @BrianDrummond I don't know much about RF, but I don't want to demodulate the signal at all, just isolate and amplify (and square it up). I don't think a direct conversion receiver would work for that. \$\endgroup\$ – Nick Johnson Jun 3 '15 at 12:22
  • \$\begingroup\$ i would like to see an answer to this question! If my wristwatch can receive the timecode from this signal then it can surely be received on a very small antenna. edit I found this reference about antennas for 60kHz. I'm sure by now you have already solved this issue... perhaps you can share with us and provide your own answer! \$\endgroup\$ – Mark Ch Jan 7 '16 at 22:48

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