[OZAPRS] Re: [amsat-bb] Online atomic clock

Norm, VK2XCI vk2xci at aanet.com.au
Wed Sep 14 09:04:46 EST 2005

Sorry about the cross post, but this is becoming interesting.

Tony Langdon (ATC) wrote:
>>This recent thread caused me to wonder about the dynamic 
>>nature of the internet and variable propagation delays. Does 
>>anyone know the relative accuracy - at your computer - of 
>>"internet" timing services as compared to "hard-wired" timing 
>>services as are available in many cities in many countries?

For the APRS crowd... does any one have a clue how to discipline the PC 
clock from GPS?? Sounds interesting!
> For Internet based timekeeping, NTP is your best bet, as NTP does all it
> to compensate for propagation/packet delivery delays.  For specs, the
RFC on
> NTP (it'll be a heavy read :) ) will tell you the answer, but I believe
> accuracy can be surprisingly high, especially if you choose a time
> that's relatively close to you and then use full NTP (rather than SNTP)
> that server. SNTP is good for sycing between a gateway time server on
> LAN and all the other PCs, if acuracy is important.  


FWIW, I use Tardis 2000/K9 (the Doctor Who fans will appreciate it!) 
Tardis is an NTP client... gets the time from an NTP service, as well as 
a server, serving the time to other PCs on your LAN. K9 is the 
client-only app which runs on the LAN PCs. Both will run as a service on 
Win2k, tardis has a 1K memory footprint, K9 similar.

There are Linux versions!


Disclaimer: I have no association with the writer, distributor or seller 
of the software, simply a long time satisfied customer

Norm, VK2XCI,
Mildura, Australia
The Wintersun City
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ozaprs at marconi.ics.mq.edu.au

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