A note on using a Raspberry Pi as a NTP server. In my limited home lab testing the RPi server had enough instability that Internet time sources were always preferred by my workstation after ntpd had been running for a while. Presumably this was due to the RPi's clock frequency drifting. At some point I will look at it again. If you do want to build your own Stratum 1 server you might want to glance at: https://github.com/meekj/ntp/blob/master/jon_meek_ntp_poster2009a.pdf and the references there. I had hoped to use the very low cost RPi Stratum 1 servers at $DAY_JOB, but the test device was clearly not up to the job. At some point I hope to revisit this and do some more testing like I did for that poster. I'll add in a CDMA server and a dedicated WWVB receiver. Jon