Hi Well …. 1Hz at 60KHz is …. errr … (off to Google Calc …) …. 16.67 ppm. That’s a pretty major lock range for a TCXO. It’s likely > 10X what an OCXO will do. What the bare crystal in a watch will do … who knows.
Bob > On Aug 26, 2018, at 5:52 PM, paul swed <paulsw...@gmail.com> wrote: > > Looks like the signal has to be with in 1 hz. I new it was tight. > Need a bit more experimentation across the several receivers though they > all use the same approach with a sharp Xtal filter. > > > On Sat, Aug 25, 2018 at 8:24 PM, paul swed <paulsw...@gmail.com> wrote: > >> My mistake the chronverter uses a pic 12f1840. >> >> On Sat, Aug 25, 2018 at 8:23 PM, paul swed <paulsw...@gmail.com> wrote: >> >>> Have to look at what oscillators and crystals I have then a divide. >>> Thats old style and most likely the junk box has everything. >>> Have to look in my box of tricks as I built several chains for the >>> de-psk-er experiments. >>> Have to agree on the micro the chronverter uses a pIC 12F64 as I recall >>> and it has quite a nice set of dividers in it. Just not an external crystal >>> input so a better oscillator can be used. Getting lazy these days. >>> I have some number of tcxos from a company called vectron. Several cards >>> of each. Can't imagine how I came by those. >>> :-) Believe the lowest freq was 12 MHz. >>> Regards >>> Paul. >>> >>> >>> On Sat, Aug 25, 2018 at 8:07 PM, Bob kb8tq <kb...@n1k.org> wrote: >>> >>>> Hi >>>> >>>> A pretty simple modest Q tuned circuit on the output of a gate will turn >>>> the square wave >>>> into a sine. Not much to it since there are a lot of power supply >>>> components out there that >>>> work fine at 60 KHz. In order to get a stable 60KHz, a divider is the >>>> way to go. I’d probably >>>> use one that’s built into an MCU as part of a timer or something >>>> similar. >>>> >>>> Bob >>>> >>>>> On Aug 25, 2018, at 7:00 PM, paul swed <paulsw...@gmail.com> wrote: >>>>> >>>>> Bob The generator sig is 60 Khz sinewave.but as a I build up a divider >>>>> chain and such your idea makes great sense. >>>>> Then filter to 60 KHz. >>>>> But I see the issue with the Chronverter carrier its 120-150 Hz high. >>>>> Bounces around a fair amount. >>>>> There could be a secondary issue in that the carrier may not actually >>>> be >>>>> phase stable. >>>>> It really doesn't matter as for the Truetimes and Spectracoms its >>>> simply >>>>> not good enough. >>>>> I still need to try the cheapy clocks as that is what it was intended >>>> for. >>>>> Not throwing stones as so much of what it does saves me a bunch of >>>> coding >>>>> and doing exactly what Dave did. >>>>> Regards >>>>> Paul >>>>> WB8TSL >>>>> >>>>> On Sat, Aug 25, 2018 at 5:31 PM, Bob kb8tq <kb...@n1k.org> wrote: >>>>> >>>>>> Hi >>>>>> >>>>>> You can do the 14 db deep modulation with a tristate gate and a pair >>>> of >>>>>> resistors. >>>>>> Ground the input and feed the “modulation” signal to the tristate >>>> control. >>>>>> >>>>>> Bob >>>>>> >>>>>>> On Aug 25, 2018, at 4:35 PM, paul swed <paulsw...@gmail.com> wrote: >>>>>>> >>>>>>> From the earlier threads OOK modulation does not work for high end >>>> clocks >>>>>>> like spectracoms and truetimes. Have not tried it on the cheapy >>>> clocks >>>>>> yet. >>>>>>> >>>>>>> I added an external modulator. A dg419 analog switch and then with a >>>> few >>>>>>> resistors added DC offset and anttenuation so that the carrier drops >>>> by >>>>>> -14 >>>>>>> db per the wwvb spec. The logic control is driven from the >>>> chronverter >>>>>> and >>>>>>> it totally works. Spectracom Netclock 2 locked up in the normal time. >>>>>>> There are far better modern single supply analog gates that will >>>> work. >>>>>> Just >>>>>>> did not have any. >>>>>>> >>>>>>> The 60 KHz carrier is supplied by a fluke 6060 generator. This >>>> eliminates >>>>>>> any chance of being off frequency and is not the long term answer. >>>>>>> >>>>>>> The chronverter actually uses a dallas semiconductor clock chip thats >>>>>>> reasonably accurate.(dangerous to say on time-nuts) So that even if >>>> you >>>>>> do >>>>>>> not add the GPS receiver it will run quite some time correctly after >>>>>>> setting the time. >>>>>>> >>>>>>> Chronverter draws 6 ma from a 5 V supply. I always like low power. >>>>>>> >>>>>>> All in all a very nice answer to what do we do if WWVB goes away. >>>>>>> As mentioned it handles timezones and DST and you can change DST if >>>> those >>>>>>> silly politicians screw with it again. >>>>>>> >>>>>>> Speculation >>>>>>> The chronverter actually puts out carriers for the popular LF >>>> stations >>>>>>> along with the time codes for them. >>>>>>> >>>>>>> Though the modulator allows quality clocks to lock I speculate the >>>>>>> frequency from the chronverter is not tight enough. All of these >>>> clocks >>>>>>> have very sharp crystal filters in them. 10 Hz. Plan to measure the >>>>>> output >>>>>>> of the chronverter see what the 60 KHz is actually at. Though >>>> listening >>>>>> on >>>>>>> a HP3586 receiver it appears pretty close to frequency maybe its >>>> just not >>>>>>> good enough. Or the fact is OOK modulation does not work because it >>>> gaps >>>>>>> the PLL in these clocks. >>>>>>> >>>>>>> Next steps >>>>>>> >>>>>>> - Determine and lay to rest the OOK/need for external modulator. >>>>>>> - Power amplifier and loopstick transmitting antenna staying at or >>>>>> below >>>>>>> 30uv@30 meters. >>>>>>> - Integrate a neo6 GPS receiver in. (Seriously easy) >>>>>>> - >>>>>>> - Box it up. >>>>>>> >>>>>>> Have my eye on one of the Truetime DC468 units and the classy >>>> panelplex >>>>>>> display. >>>>>>> >>>>>>> Hope this helps those of you concerned with what to do should WWVB go >>>>>> away. >>>>>>> Regards >>>>>>> Paul >>>>>>> WB8TSL >>>>>>> _______________________________________________ >>>>>>> time-nuts mailing list -- time-nuts@lists.febo.com >>>>>>> To unsubscribe, go to http://lists.febo.com/mailman/ >>>>>> listinfo/time-nuts_lists.febo.com >>>>>>> and follow the instructions there. >>>>>> >>>>>> >>>>>> _______________________________________________ >>>>>> time-nuts mailing list -- time-nuts@lists.febo.com >>>>>> To unsubscribe, go to http://lists.febo.com/mailman/ >>>>>> listinfo/time-nuts_lists.febo.com >>>>>> and follow the instructions there. >>>>>> >>>>> _______________________________________________ >>>>> time-nuts mailing list -- time-nuts@lists.febo.com >>>>> To unsubscribe, go to http://lists.febo.com/mailman/ >>>> listinfo/time-nuts_lists.febo.com >>>>> and follow the instructions there. >>>> >>>> >>>> _______________________________________________ >>>> time-nuts mailing list -- time-nuts@lists.febo.com >>>> To unsubscribe, go to http://lists.febo.com/mailman/ >>>> listinfo/time-nuts_lists.febo.com >>>> and follow the instructions there. >>>> >>> >>> >> > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.