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Recommendations for automatic PC clock sync program?



At 11:28 4/15/06 -0400, you wrote:
>I want to keep my PC clock as accurate as possible for the benefit of my
>tracking program so I thought I would download one of the automatic clock
sync
>programs available on the web. I googled for it and found out I have a bunch
>of choices. Any reccomendations?
>Thanks,
>Michael, W4HIJ
>----
		++++++++++++++++++++++++++++++++++++++++++++++++++
								15 April 2006
	W4HIJ de G3BVU/W1     BT
	Michael,

		There is a significant array of programmes, both "freebie" and pay,
available for use on the Internet. You can also interface with several
National Time Services via a telephone line. However what if you want your
clock to be accurate even if: -

  1. 	your Internet connection "goes down", ý la Katrina, etc?

  2.	you are operating "mobile" or are "portable" at a hilltop site during
a Contest?

 3.	you are operating /MM?

	The answer is "Use NOVA GPS ($20.00 registered version) plus the GPS
satellite signals". 
  1.	Hand-held GPS receivers that have a data port usually output date and
time data in the NMEA-0183 format. Input this to your PC and NOVA GPS will
lock your computer's clock to "GPS Time", typically accurate to better than
0.5 second.

  2.	For more accurate time keeping, use a Jupiter-T receiver. This outputs
the standard, low accuracy, NMEA-0183 format sentence plus two other
outputs. The latter are a 10KHz waveform and a 1 second marker, the leading
edge of which is locked to the 10KHz waveform. The 10KHz waveform and 1
second marker's leading edge are accurate to a few 10s of nano-seconds!

	I have been using (and still use) NOVA GPS for several years. It drives 4
desktop PCs without any problem. Monitoring the instantaneous differentials
I see random 10s of milli-second changes some of which, I think, may be due
to the PC's "Windows Interrupt" system.

	A current project is to use a Jupiter-T receiver to lock my Disciplined
10MHz Oscillator (HP5254-L) to GPS or UTC time and use the 10MHz output as
a reference for microwave local oscillators.

	I'm currently looking for a source of the Jupiter-T receivers. All
pointers to a source(s) will be greatly appreciated.

	73s,   de John  G3BVU   SK
----
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