My mistake the chronverter uses a pic 12f1840. On Sat, Aug 25, 2018 at 8:23 PM, paul swed <[email protected]> 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 <[email protected]> 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 <[email protected]> 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 <[email protected]> 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 <[email protected]> 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 -- [email protected] >> >>> To unsubscribe, go to http://lists.febo.com/mailman/ >> >> listinfo/time-nuts_lists.febo.com >> >>> and follow the instructions there. >> >> >> >> >> >> _______________________________________________ >> >> time-nuts mailing list -- [email protected] >> >> To unsubscribe, go to http://lists.febo.com/mailman/ >> >> listinfo/time-nuts_lists.febo.com >> >> and follow the instructions there. >> >> >> > _______________________________________________ >> > time-nuts mailing list -- [email protected] >> > To unsubscribe, go to http://lists.febo.com/mailman/ >> listinfo/time-nuts_lists.febo.com >> > and follow the instructions there. >> >> >> _______________________________________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to http://lists.febo.com/mailman/ >> listinfo/time-nuts_lists.febo.com >> and follow the instructions there. >> > > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
