[ntp:questions] Getting NTP to correct only the clock skew

Spoon devnull at ntp.isc.org
Sat Apr 14 11:04:44 UTC 2007


Steve Kostecke wrote:

> Spoon wrote:
>
>> In my situation, I don't care what time it is, but my clock needs
>> to tick at the correct rate.
> 
> The least expensive means of getting your clock to tick at the correct
> rate is to synchronize it to the ubiquitous time-base known as UTC.
> 
>> I think I can't use GPS because the computer is located in a server
>> room underground.
> 
> Can you run an antenna cable down to the bunker? That would allow you so
> place an antenna top-side and the GPS receiver underground:
> 
> http://www.meinberg.de/english/products/gps170pci.htm

As far as I could tell, that board costs over 1000 USD.
Or am I mistaken?

> http://www.microsystemes.com/PDF%20FICHES%20PRODUITS/fp0156.pdf
> http://www.spectracomcorp.com/Home/Products/BuslevelTimingBoards/TSATPCIGPSTimingBoard/tabid/378/Default.aspx

Do you know the price of these solutions?

> If you can receive CDMA cellphone signals in the bunker you could use a
> product such as the Endrun Technologies PraecisCT:
> 
> http://www.endruntechnologies.com/network-time-source.htm

Do you know the price of this solution? Is the signal sent in the clear, 
or do I need some form of monthly subscription?

>> Are there other PPS sources? I've read about rubidium and cesium clock 
>> sources. How expensive are they?
> 
> Here's one rubidium oscillator (you'd have to package it into a complete
> solution): Sanford Research PRS10 $1495 US / $1695 international

Atomic clocks seem to be out of the question:
My budget is 250 USD per unit maximum.

> Here are some links for complete solutions (you have to request prices):
> http://www.bvsystems.com/Products/Lab/Rhino/rhino.htm
> http://www.labx.com/v2/spiderdealer2/vistasearchdetails.cfm?LVid=3345327

I'm looking for something I could attach / plug into an existing system.

Regards.




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