[time-nuts] Advice on NTP server needed
jason at extremeoverclocking.com
Mon Jun 13 22:45:02 UTC 2011
I have to disagree with the person that said the Net4501 is not stable. I have two (soon to be 3) that run NTPns and they have never
needed to be touched. I've powered them down a couple times during really bad storms because I didn't want lightning to zap them (or
my other GPS equipment).
If you don't have any time constraints, you can watch eBay and usually get a Net4501 for $50 - $75 shipped. You can buy the latest
Motorola Oncore timing receiver (M12M+T ?) from Synergy GPS, or on eBay the user fluke.l is selling older M12+T models for $35 + $8
shipping. Get an appropriate cable to go from the GPS unit to your antenna, solder a few wires, and you are good to go.
Here's a pic of mine with the M12+T:
Here's an article I wrote building one with a UT+ receiver.. Took a little more work but results are the same:
John's article is also a good read:
I have precompiled images of NanoBSD + NTPns on my server if you want to download them (email me off-list for the URLs). One build
is FreeBSD 6.3, the other is 7. I haven't built any trying newer versions of FreeBSD, I don't think there is really anything to
except a bunch of build headaches.
If you want something more plug & play... Watch eBay for "Tymserve 2100", which seem to be the most common. There was a bunch of
"Spectracom" GPS Time servers that recently sold for ~$100 each IIRC. I don't know if anymore are available. Every now and then an
"EndRun" or "Brandywine" unit will show up. Other useful keywords to search eBay would be "Symmetricom", "Datum", and "TrueTime".
Oh, and of course there's the Trimble Thunderbolt... You can hook that up to a PC / serial port as a GPS input. Since it has its own
internal OCXO you also get some hold-over ability.
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