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 <wayne.hol...@gmail.com> 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 <organli...@pacbell.net> 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 -- 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.