A bit more reading if you block the phase comparison from -50ms to 150ms of the tick you get a 0 carrier phase no modulation. That also explains why I thought I could here some sort of phase modulation because there is. So as an example if you use a GPS tick its really simple to block the phase changes and only measure the 0 phase carrier. Essentially a 200 ms carrier gap per second. Thats quite a clean format you have to work with. Regards Paul WB8TSL
On Mon, Mar 6, 2017 at 8:19 PM, paul swed <[email protected]> wrote: > I checked out 162KHz at 2000 local and now have what I believe to be TDF > using the 67 ft vertical antenna. I am reading -82 dbm near Boston in the > US or 3400 miles. A comfortable signal at least in the winter. As a > comparison wwvb at 60 KHz is -77dbm some 2000 miles but also not at a 2 MW > power level like TDF. > > Since I had not heard TDF before I listened to Pieters online SDR radio to > see what to listen for. The easiest point to notice is the 59 second phase. > Its funny that also seconds 0-10 should be the same phase but it did not > seem to be true. Unless what I am hearing is the local oscillator of > Pieters SDR radio. > > So thanks for sharing some new knowledge with Time-nuts. > Regards > Paul > WB8TSL > > On Mon, Mar 6, 2017 at 1:46 PM, Pieter-Tjerk de Boer < > [email protected]> wrote: > >> >> On Sun, Mar 05, 2017 at 10:42:52PM +0000, Iain Young wrote: >> >> > That's TDF from France. Their equivalent of WWV/MSF/DCF. >> >> > Average phase and frequency deviation is >> > zero over 200msec (see link above for details) >> >> This is not quite correct, since the transmitter does not just carry the >> time data (one bit per second, in the first 200 ms of the second), but >> also some more data during the next 700 ms of each second. >> The latter data is coded in a way which does not guarantee that the phase >> or frequency average is zero other than when averaging over the entire >> 700 ms block. >> Then again, I've been told that although there is a nicely defined framing >> format, in reality it has only ever transmitted idle frames, so in >> practice >> it's a fixed pattern which repeats every minute and thus could be >> cancelled >> for use as a frequency reference. >> >> I have a live online decoder for TDF's signal at >> http://websdr.ewi.utwente.nl:8901/tdf/ >> >> Regards, >> Pieter-Tjerk, PA3FWM >> >> _______________________________________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to https://www.febo.com/cgi-bin/m >> ailman/listinfo/time-nuts >> and follow the instructions there. >> > > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
