[time-nuts] List of time synchronization hardware and software
james.h.maynard at usa.net
Mon Jan 16 17:51:19 EST 2006
Alan Kruse wrote:
> I was referring to a list of hardware or software that will provide time.
> On 1/16/06, Rob Kimberley <time.bandit at btinternet.com> wrote:
>>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.
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,
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
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.
Salem, Oregon, USA
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