On Jan 20, 4:05*pm, Telamon
wrote:
In article , David
wrote:





Geoffrey S. Mendelson wrote:
John Kasupski wrote:
Note that we're probably talking errors in the amount of nanoseconds
(per second) here, certainly not errors that are going to cause
somebody to be ten minutes late for work, but for commercial or
scientific applications requiring a time reference that is related
directly to a national or international reference, GPS may not
necessarily cut the mustard.

Yes, but don't loose sight of the fact that this discussion is really
about consumer items. One person metioned in a previous post that his
clock syncs three times a week, other than that, it "runs free".

So IMHO if you build a consumer device that syncs every 5 minutes to
a GPS or GPS based standard, it will be a lot more accurate than
the average one that syncs every 2-3 days to a radio signal.

If it were to sync every minute to a time signal inserted in a cellular
control channel, it be even more accurate. Last I checked, the AT&T
Wireless 850mHz GSM (whatever name it is called now) network covers 98%
of the surface area of the U.S.

Since it is a receiver it can be broadbanded and if it were to cover
the GSM 850/900 mHz and 1800/1900 mHz bands it would work everywhere
there is GSM coverage. Except for Estonina and Brazil, an 850/900 mHz
receiver would be enough.

This does leave out parts of the Pacific Rim (Japan and Korea) and
some parts of Oz, but on the whole it cover almost the entire
populated earth.

Geoff.

Much of the western USA has no cellular service period.

Most of the population is on the coast and has cell service.

--
Telamon
Ventura, California- Hide quoted text -

- Show quoted text -

Telamon,

'Most' Ain't "All" and when there is a major Power Grid
disruption you will be yelling into your Celphone :
HELP ! - Can Any Body Hear Me ? and nobody will.

David was Right the CB Radio is still one of the Best Emergency
Back-Up Communications Systems Dollar-for-Dollar for the
majority of Non-Technical Consumers in an Emergency :
When the Power System Goes Down.

RadioShack CB Radios - http://tinyurl.com/35n497

That is very true -IF- you live in many rural and remote areas
at the far-end of the Power Line. Either a Car/Truck 12 Volt
power source or a spare 12 V Battery is required. ~ RHF