G+_Dallam Oliver-Lee Posted September 23, 2014 Share Posted September 23, 2014 I got a great show idea for you on know how to run your own NTP server being sync via GPS. Got my NTP server running at Stratum 1 completely setup now after figuring out the exact time offset between GPS to computer via serial at 4800buad (about 0.530 seconds). The PS2 to serial adapter is sold separately from the GPS receiver. Overall cost was $30 USD. GPS: GlobalSat BR-355 Serial GPS Receiver? Link to comment Share on other sites More sharing options...
G+_Luke Militello Posted September 24, 2014 Share Posted September 24, 2014 I did this a few years ago as well using Garmin 18x LVC GPS modules. Did mine with Ubuntu, however FreeBSD is best if you want nanosecond precision, but with the line latency that this setup produces over serial, I find the microsecond precision Linux offers to be just fine. When I did this, it was well before the Linux kernel had PPS enabled, so I had to patch the kernel and recompile my own. I did this on the 2.6.32 base. Not sure if your GPS is PPS capable, but when you have one that is, not only can your NTP server get the date and time, but the GPS can control the NTP drift by ensuring it is "on time" every second. On that note, only the Garmin 18x LVC has PPS support, the other two 18x models of the USB and DB9 flavors do not. I'll also go as far to mention that I have been working on a GPS disciplined OCXO that will be able to output frequencies between 1Hz to 10kHz in powers of 10 increments. If more people are interested, I can dig up some of the pictures of my setup to share as well. Link to comment Share on other sites More sharing options...
G+_Jason Perry Posted September 26, 2014 Share Posted September 26, 2014 Luke Militello I would love to see those Link to comment Share on other sites More sharing options...
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