search for: wwvb

...les, which means additional software if you want it to track changes to these things. There were 10 batches of such changes last year! This really has no bearing on time source; none of the commonly-used time sources (satellite, terrestrial radio, or network) carry time zone information (although WWVB does carry a bit to indicate if US DST rules are in effect). They each use a single global time scale (although unfortunately, not the _same_ time scale). > GPS time is a much better solution, but it?s power-hungry, as you probably know from running GPS on your smartphone. This rules it out f...

...gt; On May 24, 2017, at 7:53 AM, Chris Olson <chris_e_olson at yahoo.com> wrote: > > > > One of our STEM interns recently observed that there are > > inexpensive clocks that sync via radio to standard time > > services. > > There are two major types: > > 1. WWVB and its equivalents in other countries: > > https://en.wikipedia.org/wiki/WWVB > > 2. GPS clocks. > > > WWVB has several problems: > > a. It?s transmitting from a fixed location in a time zone you probably > aren?t in ? US Mountain ? being the least populous of the...

...e sources (satellite, terrestrial radio, or network) carry time zone > information In editing my prior reply, I removed the observation that GPS solves problem ?a? by telling you where you are in the world, as well as what the UTC time is. It still has problems b and c, though. > (although WWVB does carry a bit to indicate if US DST rules > are in effect). ?which is of no help when the DST rules are hard-coded into the clock, as they are so frequently. I had to discard a few WWVB clocks when the last DST rules went into effect. >> GPS time is a much better solution, but it?s p...

...network) carry time zone >> information > > In editing my prior reply, I removed the observation that GPS solves > problem ???a??? by telling you where you are in the world, as well as what > the UTC time is. > > It still has problems b and c, though. > >> (although WWVB does carry a bit to indicate if US DST rules >> are in effect). > > ???which is of no help when the DST rules are hard-coded into the clock, > as they are so frequently. I had to discard a few WWVB clocks when the > last DST rules went into effect. > >>> GPS time is a...

One of our STEM interns recently observed that there are inexpensive clocks that sync via radio to standard time services.? This begged a question about why every computer would not have a radio module to receive time.? Our senior staff did not have a good answer or if time from such a radio module would be supported by the operating system. When I was a student, such questions would have earned

On May 24, 2017, at 7:53 AM, Chris Olson <chris_e_olson at yahoo.com> wrote: > > One of our STEM interns recently observed that there are > inexpensive clocks that sync via radio to standard time > services. There are two major types: 1. WWVB and its equivalents in other countries: https://en.wikipedia.org/wiki/WWVB 2. GPS clocks. WWVB has several problems: a. It?s transmitting from a fixed location in a time zone you probably aren?t in ? US Mountain ? being the least populous of the lower 48?s four time zones. You therefore h...

...altsev wrote: > It is insightful, yet... There are a bunch of other factors that may need > to be taken into account. Angular transmission pattern of satellite (horn? > or is it yagi? antenna) vs ground based (monopole? or dipole? antenna - > which one is used there to transmit in HF?). WWVB uses a two-element phased array, where each element is a 400-ft top-loaded vertical monopole. The ERP is listed as 70kW, so the antenna gain is already applied to the transmitted signal's specification and thus doesn't need to be considered. (Lots of technical data can be found in NIST...

A few years ago, one of our interns was curious about system time keeping features in computer systems.? This intern was also the proud owner of an inexpensive Radio-Controlled Clock. The intern wondered why computer motherboards were not just equipped with a chip like the ones in the RCC so that their system time would always be correct. I posted a question about this on the CentOS email list