Hi Go indoors in the basement inside an inner room. You can at some times of day get WWVB. With a normal building, GPS isn’t going to make it. Even if it does, the signals will be degraded enough that you will have a tough time using in.
Bob > On Dec 31, 2018, at 8:47 PM, Wayne Holder <wayne.hol...@gmail.com> wrote: > >> If you are fairly deep inside a building, GPS isn’t going to get there. > WWVB likely >> will make it to an internal location. > > Interesting thought. I wonder if anyone has tested WWVB reception in a > deep underground location such as a sub sub level in a building or parking > garage? > > Wayne > > On Mon, Dec 31, 2018 at 5:29 PM Bob kb8tq <kb...@n1k.org> wrote: > >> Hi >> >> If you are fairly deep inside a building, GPS isn’t going to get there. >> WWVB likely >> will make it to an internal location. >> >> If you are convinced that WWVB is un-jamable and that GPS is easily >> jammed, WWVB >> would be more robust. >> >> That’s about it. >> >> Bob >> >>> On Dec 31, 2018, at 7:56 PM, Wayne Holder <wayne.hol...@gmail.com> >> wrote: >>> >>> While reading this thread and pondering whether to buy and fool around >> with >>> an ES100-based module from Universal Solder, I suddenly found myself >>> wondering if there was any advantage to using the time received from WWVB >>> vs just using an inexpensive GPS receiver. The ES100 module costs about >>> $70, but I can get a GPS receiver, with antenna, for far less than that >> and >>> I've had no trouble receiving GPS signals indoors with most modern >> receiver >>> modules. >>> >>> I suppose the low power requirements of the ES100 might be an advantage >>> when building battery powered clocks to mount on the wall, but it seems >>> like some of the newer, ultra low power GPS modules intended for use in >>> smart watches could also work in a battery-powered wall clock, especially >>> if the receiver was only powered on a few times a day to update the time. >>> >>> And, finally, if GPS modules are (or will some become) a suitable >>> replacement for WWVB receiver modules, do we really need WWVB in the >> modern >>> age? Perhaps there's some critical advantage to using WWVB to get the >> time >>> but, offhand, I cannot think of it. What am I missing? >>> >>> Wayne >>> >>> On Mon, Dec 31, 2018 at 4:30 PM Brooke Clarke <bro...@pacific.net> >> wrote: >>> >>>> Hi Joseph: >>>> >>>> Thanks for the patent link. I've added it to my WWVB phase modulation >>>> info at: >>>> https://prc68.com/I/Loop.shtml#La_Crosse_UltrAtomic >>>> >>>> -- >>>> Have Fun, >>>> >>>> Brooke Clarke >>>> https://www.PRC68.com >>>> http://www.end2partygovernment.com/2012Issues.html >>>> axioms: >>>> 1. The extent to which you can fix or improve something will be limited >> by >>>> how well you understand how it works. >>>> 2. Everybody, with no exceptions, holds false beliefs. >>>> >>>> -------- Original Message -------- >>>>> On Mon, 31 Dec 2018 12:00:02 -0500, time-nuts-requ...@lists.febo.com >>>>> wrote: >>>>> >>>>>> time-nuts Digest, Vol 173, Issue 44 >>>>>> Message: 7 >>>>>> Date: Mon, 31 Dec 2018 04:04:22 -0800 >>>>>> From: "Tom Van Baak" <t...@leapsecond.com> >>>>>> To: "Discussion of precise time and frequency measurement" >>>>>> <time-nuts@lists.febo.com> >>>>>> Subject: Re: [time-nuts] More ES100 WWVB Measurements >>>>>> Message-ID: <96BB388753294278A9CDE96C1EA7D9AE@pc52> >>>>>> Content-Type: text/plain; charset="UTF-8" >>>>>> >>>>>> Hi Graham, >>>>>> >>>>>> That's very nice work. And you have uncovered several unusual effects >>>>>> in the ES100. Bugs? Features? If we time nuts keep up the good work >>>>>> to evaluate this chip, we are likely at some point to get an >>>>>> informative response from the guys who designed it. They read >>>>>> time-nuts. >>>>> I didn't see this mentioned, but I think I have found the relevant US >>>>> patent application: US20130051184A1, Real-time clock integrated circuit >>>>> with time code receiver, method of operation thereof and devices >>>>> incorporating the same, Oren Eliezer et al, Oren Eliezer et al, filed >>>>> 2013-02-28. >>>>> >>>>> .<https://patents.google.com/patent/US20130051184> >>>>> >>>>> Found this by chasing stuff from the EverSet website: >>>>> .< >>>> >> http://everset-tech.com/wp-content/uploads/2014/11/ReceiverRadioClocks.pdf >>>>> . >>>>> >>>>> Joe Gwinn >>>>> >>>>> >>>>>> So now both you and Tim have observed the off-by-one-second (or >>>>>> off-by-N-seconds) effect in the ES100. I wonder if this explains why >>>>>> some of my ES100-based La Crosse 1235UA Ultratomic wall clocks are >>>>>> off by a second sometimes. >>>>>> >>>>>> My main question: in your "Time Plot.PNG" plot, what is the cause of >>>>>> the sawtooth pattern? The points are almost all on a clear negative >>>>>> slope, though bounded by roughly +/- 75ms. Looking on the far left, I >>>>>> see a time drift of +50 ms to -25 ms over an hour, which is >>>>>> equivalent to a -20 ppm frequency offset; about -2 seconds/day. >>>>>> >>>>>> Do you think this is due to the 16 MHz onboard xtal? If so, how about >>>>>> changing the temperature of the eval board by a lot (say, several >>>>>> tens of degrees) for an extended time (say, 4 hours) and see if the >>>>>> sawtooth slope changes convincingly. >>>>>> >>>>>> Also, just to be sure, can you put a known independent timing signal >>>>>> (e.g., GPS/1PPS) into your complex BeagleBone Black / Debian 9.4 / >>>>>> ntpd time server / Python 3 / Excel stack to establish the validity >>>>>> of your measurement methodology? Very likely you did it right, but I >>>>>> always cringe when I hear "Linux" or "NTP" and "precise time" in the >>>>>> same sentence. Yes, sorry, forgive me; I grew up in the "trust, but >>>>>> verify" generation [1]. It applies pretty well to metrology also ;-) >>>>>> >>>>>> /tvb >>>>>> >>>>>> [1] https://en.wikipedia.org/wiki/Trust,_but_verify >>>>>> >>>>>> >>>>>> End of time-nuts Digest, Vol 173, Issue 44 >>>>>> ****************************************** >>>>> _______________________________________________ >>>>> 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.
