said by voxframe:
We run our own NTP server, but it's not GPS synced.
You can buy the inexpensive GPS/PPS kit from Sure Electronics. It is used widely to build Linux NTP servers.
We designed a single box which incorporates DNS rapid resolver, NTP server and encrypted logging to SDXC cards. Satisfies past, present and future law enforcement requirements without compromising customer privacy.
*** The gps board is only $35 and in stock. »www.sureelectronics.net/goods.php?id=99