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2005-02-21

Time accuracy without the Internet

A discussion over at Chaos Manor led me to recall the utter provincalism of folks in the US, which is puzzling, considing most of y'all's only been here for a couple of hundred years, due to unfortunate lapses in Homeland Security:

"Geoff" wrote:
>Motorola /Nextel makes at least one series of cellphones (i710, i730,
i733) which contain a GPS chipset.

However, these won't work without the NEXTEL iDEN cellular network... and, iDEN is not deployed in Uganda. Global Systeme Mobilé phones which work on 900 or 1800 MHz might, if they are available, can provide a time check, but like most other cellphones, they are small and easily stolen, plus require a service agreement for each phone (spendy).

Instead, WWV and its sister station WWVH & WWVB can be tuned with inexpensive shortwave radios. However, the 5.000 MHz frequency commonly used is shared with other stations, including ZUO on Cape Town, RSA. There are non-US alternatives which might reach Uganda better, especially ZSC, also in Cape Town, RSA, on 418 KHz and 4.291, 8.461, 12.724 and 17.018 MHz. Lists follow:

http://ac6v.com/standard.htm
http://www.npl.co.uk/time/time_trans.html
http://www.answers.com/topic/radio-clock
http://www.cl.cam.ac.uk/~mgk25/lf-clocks.html
http://www.smeter.net/stations/hf-time-frequency.php

There's freeware program to sync a PC with station MSF in Rugby, England. and parts may be had here and here.

Off-the-shelf solutions are here:
http://www.wharton.co.uk/expansion/484.htm
http://www.galsys.co.uk/atomic-clock/msf-rugby-atomic-clock.htm
http://www.atomicclockrugbymsf.co.uk/ntp-time-server/ntp-server.html
http://www.tapr.org/tapr/html/Ftac32.html
http://www.timetools.co.uk/atomic-clock-software.htm
http://www.timetools.co.uk/time-server.htm#low-cost%20radio%20atomic%20clock
http://techpubs.sgi.com/library/tpl/cgi-bin/getdoc.cgi?coll=0650&db=relnotes&fname=/usr/relnotes/ntp#Changes%20and%20Additions
http://www.precitel.com/clocks_pages/rs-dataclock_e.html
http://www.precitel.com/clocks_pages/pc-precitime_e.html
(The latter can work with stations other than MSF as well.)

CHU Canada is said to offer a time signal that's easy to read by any Bell 103 modem (an oldie goldie, but whose features are incorporated in just about any external modem). Also see http://inms-ienm.nrc-cnrc.gc.ca/time_services/shortwave_broadcasts_e.html - and you might e-mail them at radio.chu@nrc.ca to inquire if they have QSL cards confirming reception in Uganda, and if so, on which frequencies.

The signal quality of MSF and alternatives could be verified through the good graces of the Uganda Amateur Radio Society [UARS]. Multiple contacts are listed at http://www.qsl.net/arsk/address.htm.

Other parts suppliers may also be found at http://www.hkw-elektronik.de who might be familiar with the parts required to sync with station DFC-77.

This is simpler than a homebuilt interface to an existing US $98 GPS device, as this gentleman hacker has created, and maybe less spendy than NMEA software for Windows - see
http://www.kaska.demon.co.uk/tardis.htm with a wired NMEA-compliant GPS
and the all-important Cable as we must remember Pournelle's Law.

The original poster did not mention which OS was to be used in those computers to deploy in Uganda. That would be relevant information to know, as although WinNT, Win2K & WinXP have SNTP software which could be modified, Win9x & ME do not. This Sourceforge offering could be useful if an automated Win9x solution is needed.

Here's an Apple driver, and xntp is the standard, AFAIK, in the Unix/Linux world. Here's a
how-to for assembling radio parts to make a receiver which will talk to it.

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