Frequency Reference for NTP Use?

Tomasz Ciolek tmc at
Sun Jul 14 00:37:30 EST 2002

But why? talk the csiro in Sydney. they have a cesium clck level2 and
level1 NTP master sites. Maybe they'll let you get a feed?


On Sun, Jul 14, 2002 at 12:27:20AM +1000, Alex Satrapa wrote:
> On Saturday, July 13, 2002, at 10:06 , Brad Hards wrote:
> >A few seconds a month is probably going to require some kind of 
> >temperature
> >stabilisation.
> When you move from temperature compensated oscillators to ovenised* 
> oscillators, you move from 1 second/week to about 1 second/year 
> stability.  You also move from the order of $x00 to $x000.
> >Unless you are really concerned with GPS availability, I'd look for
> >a GPS with a 1PPS output.
> The catch is that such units are usually designed to be rack mounted, 
> and they're usually in the order of $1500.  My budget is significantly 
> less than that.
> I'll probably try to read through the NMEA driver to figure out where it 
> gets the second-edge from, and find some way of reducing the jitter - 
> such as the first character in the stream, rather than the first 
> character of the time stamp.
> The least expensive ovenised oscillator with 1PPS output I could find is 
> about $4,500.
> According to the NTP server, the jitter on the processor clocks of my 
> Pentiums is about 0.008ms.  That may actually do for the meantime.
> Alex
> * When I first read through the xntpd documentation, I read this as 
> oven-sized.  Which isn't that far off, when you see the setups that some 
> places have for their Campus' Master Clock.

Tomasz M. Ciolek	*
			* 	Everything falls under the law of change;	
<tmc at>	*	  Like a dream, a phantom, a bubble, a shadow,
<tmc at>	*	  like dew of flash of lightning.
			*	  You should contemplate like this. 
GPG Key ID: 0x7A18E49D	*	Available on

More information about the linux mailing list