[time-nuts] List of time synchronization hardware and software

[James Maynard]

Alan Kruse wrote:
> Hi,
> 
> I was referring to a list of hardware or software that will provide time.
> 
> Al
> 
> 
> On 1/16/06, Rob Kimberley <time.bandit at btinternet.com> wrote:
> 
>>Hi Al,
>>
>>When you say "time synchronisation hardware and Software" do you mean NTP
>>compatible or any hardware that will provide time. If the latter, then the
>>list is a very long one indeed. Not sure that such a list exists, but
>>interested to see what others come back with.
>>
>>Kind Regards

A clock consists of a frequency standard plus a counter.  Accordingly, a
list of "hardware" that provides time would include:

A. Mechanical wrist watches and mechanical clocks. For these, the 
frequency standard might be a pendulum, and the the counter might be an 
arrangement of gears to count seconds, minutes, houts, etc., and display 
them on mechanical dials for the user to observe.

B. Electrically powered wristwatches and clocks that include tuning 
forks as their frequency standard.

C. Electrically powered wristwatches and clocks that include crystal 
oscillators as their frequency standards.  Most retail clocks and 
wristwatches fall into this category.

D. Wristwatches and clocks that include crystal oscillators that are 
"synchronized" from time to time with radio receivers. These include, 
for example:

D.1. "Atomic Time" and other brands of wristwatches and clocks that 
synchronize their dials (counters) against the 60 kHz LF signal from 
WWVB near Ft. Collins, Colorado.

D.2. Similar products that synchronize their dials against other LF 
signals from other LF (low frequency) or MF (medium frequency) time 
signal stations such as MSF (Rughy, United Kingdom, 60 kHz); TDF 
(Allouis, France, 162 kHz); HBG (Prangins, Switzerland, 75 kHz); etc.

D.3. Similar products with HF radio receivers for such time and 
frequency stations as WWV (Colorado, USA: 2.5 MHz, 5.0 MHz,  10.0 MHz, 
15.0 MHz, 20.0 MHz), WWVH (Hawaii, USA: 5.0 MHz, 10.0 MHz, 15.0 MHz), 
CHU (Ontario, Canada: 3330 kHz, 7335 kHz, 14670 kHz), BPM (Shaanxi, 
China: 2.5 MHz, 5.0 MHz, 10.0 MHz, 15.0 MHz), etc.

D.4. Similar products that both "synchronize" their counters and 
"syntonize" their frequency references against standard time and 
frequency broadcasts.

D.5 Similar products that either "synchronize" their counters (or both 
"synchronize" their counters and  "syntonize" their frequency standards) 
against signals received from GPS satellites.  Almost any GPS receiver 
will display time of day.  (Many will not, however, display it in a 
"timely" manner!)  GPS receivers that are to be used for precise timing 
purposes should provide a 1 Hz (1 pulse per second) output.  Some of the 
better ones will provide 5 Hz or 10 Hz outputs, if they provide fixes 5 
or 10 times per second.

As Rob Kimberly said, a list of hardware timing devices could be rather 
lengthy! It would help if you could be more specific, and perhaps rule 
out such devices as mechanical clocks and chronometers.

-- 
James Maynard
Salem, Oregon, USA