Wayne always fun to see what others are doing and to learn. I would imagine the programs pretty small and could be attached here. How will you handle DST? Its a bit messy as a recent thread detailed. Plus the fact that god knows why politicians like to screw with it. Regards Paul WB8TSL
On Wed, Aug 29, 2018 at 4:35 AM, Wayne Holder <[email protected]> wrote: > As a follow up, I now have a simple WWVB simulator written in C that's now > running an an ATTiny85 using nothing more than the internal, 8 > mHz oscillator and about a 6 inch length of wire connected to one of the > pins as an antenna. It generates an approximate 60 kHz signal using PWM on > timer 1. I tweaked the timer value a bit to correct for some variance in > the internal oscillator, but I' not even sure that was necessary, as my > target is just a BALDR Model B0114ST, consumer grade "Atomic" clock. > Modulation is done by varying the duty cycle of the PWM to approximate the > -17 dBr drop on the carrier. But, again, I don't think this value is > critical with a consumer clock chip. I tapped the demodulated output > inside the clock and displayed it on my scope along with the generated > signal and I got good, steady demodulation with the wire antenna just > placed near clock. The next step is to connect up a GPS module and add > code to use it to set the time. I'm also going to change the code to use > the PPS signal from the GPS to drive the output timing rather than the test > code I have now that uses timer 0 to generate the PPS interrupt. I'm happy > to share details if anyone is interested. > > Wayne > > > > On Sun, Aug 26, 2018 at 2:51 PM, paul swed <[email protected]> wrote: > > > That would be a great neighbor to have but I can tell you around here its > > the phone. Not to concerned about someone putting up a wwvb replacement. > > And I can always up the power. Chickle. > > Regards > > Paul > > > > On Sun, Aug 26, 2018 at 2:34 PM, Bob kb8tq <[email protected]> wrote: > > > > > Hi > > > > > > The gotcha is if you have neighbors two or three doors away that *also* > > > put up one of > > > these devices. You then have a real problem with the neighbor(s) in the > > > middle. The > > > wavelength is long enough that Raleigh issues won’t get you. You still > > > have the two > > > signals ( at slightly different frequencies) beating against each > other. > > > The result is > > > going to show up as who knows what to this or that receiver. With a > > > precision receiver, > > > you might even have issues from the guy two houses away …... > > > > > > Bob > > > > > > > On Aug 26, 2018, at 1:08 PM, paul swed <[email protected]> wrote: > > > > > > > > Agree with the conversation. With respect to neighbors when the day > > comes > > > > they may ask you to boost your signal. :-) > > > > Granted maybe the day won't come but at least having your local > clocks > > > work > > > > is nice. > > > > Regards > > > > Paul > > > > WB8TSL > > > > > > > > On Sat, Aug 25, 2018 at 10:29 PM, Dana Whitlow < > [email protected]> > > > > wrote: > > > > > > > >> With the watch being physically close to the faux WWVB > "transmitter", > > > one > > > >> is in > > > >> the so-called "near field" regime, where the field strength (V/m) > > falls > > > as > > > >> the inverse > > > >> cube of the distance. If one is putting the watch, say, within a > few > > > >> inches of the > > > >> transmitter, reliable reception should be available yet the signal > > > should > > > >> be literally > > > >> undetectable by any practical receiving device more than a few feet > > > away. > > > >> Hence, > > > >> meeting the FCC field strength limit should be trivial.if the device > > is > > > >> used as pictured. > > > >> However, if one cranks up the power enough to reliably cover one's > > > entire > > > >> house, > > > >> then there might be a problem depending how close the nearest > neighbor > > > >> lives, > > > >> even at levels well within the FCC limit he quotes. > > > >> > > > >> Taking the near field relationship in hand, 40 uV/m at 300m would > > > translate > > > >> into > > > >> a whopping 0.135 V/m at 20 meters range, more than enough to feed > most > > > >> peoples' > > > >> entire house. So the pragmatic issue would again be- neighbors. On > > the > > > >> other > > > >> hand, most of them would never be aware of the local signal as long > as > > > they > > > >> get good > > > >> time settings, unless they live close enough to Ft. Collins for the > > two > > > >> signals to > > > >> contend with each other. > > > >> > > > >> It looks to me like the ferrite rod antenna is considerable > overkill. > > > Even > > > >> with no > > > >> purposeful antenna I'd expect leakage to yield sufficient signal for > > at > > > >> least a few > > > >> inches. > > > >> > > > >> Dana > > > >> > > > >> > > > >> On Sat, Aug 25, 2018 at 8:11 PM Wayne Holder < > [email protected]> > > > >> wrote: > > > >> > > > >>> This guy has what looks like a well thought out design using a > > > Sirf-Based > > > >>> GPS and ATTiny44A chip to generate a signal to update his watch: > > > >>> > > > >>> https://www.anishathalye.com/2016/12/26/micro-wwvb/ > > > >>> > > > >>> Unfortunately, he doesn't seem to have published a schematic or his > > > >> source > > > >>> code. But, he covers enough detail that I think it wouldn't be too > > > hard > > > >> to > > > >>> replicate what he's done. Or, perhaps he would disclose these > > details > > > if > > > >>> contacted. > > > >>> > > > >>> Wayne > > > >>> > > > >>> On Sat, Aug 25, 2018 at 4:33 AM, D. Resor <[email protected]> > > > >> wrote: > > > >>> > > > >>>> I thought I would search in a different way for a WWVB signal > > > generator > > > >>>> design. I found this item. While the designer explains it isn't > as > > > >>>> accurate as WWVB it may be another starting point. > > > >>>> > > > >>>> http://www.tauntek.com/wwvbgen-low-cost-wwvb-time- > > > signal-generator.htm > > > >>>> > > > >>>> > > > >>>> > > > >>>> Donald R. Resor Jr. T. W. & T. C. Svc. Co. > > > >>>> http://hammondorganservice.com > > > >>>> Hammond USA warranty service > > > >>>> "Most people don't have a sense of humor. They think they do, but > > they > > > >>>> don't." --Jonathan Winters > > > >>>> > > > >>>> _______________________________________________ > > > >>>> 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. > > > > > _______________________________________________ > > 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.
