Gilles I went back over the starting thread and believe your home brew oscillator may prevent you from getting all of the accuracy out of TDF. As I was thinking about a TRF radio and locking the question I arrived at is how do you turn 162KHz into something useful like 100 KHz 5 MHz or 10 MHz??. By getting to standard references there are many very good oven oscillators available. Regards Paul.
On Mon, Mar 6, 2017 at 10:35 PM, paul swed <[email protected]> wrote: > Actually as I think about it from the earlier part of the thread. Locking > to the carrier with a 2-4 second time constant removes the phase modulation > since its only in the first 200 ms. The 0 Phase is 800 ms in length or more > for all bits. > Now to find some nice coils for 162 KHz. > Regards > Paul > > On Mon, Mar 6, 2017 at 8:30 PM, paul swed <[email protected]> wrote: > >> 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.
