n1.taur.dk

n1 is a stratum 1 server steered by pair of GPS receivers.
n1 exists because I need a reliable source of time. One where I know it'll either give correct time, or be honest and say it is unsynchronized. I've been burned one time too many.

2020.6.28: NetworkManager
Apparently has yet another module that does bad things to TTYs. It apprarently sends commands that brings the receiver into firmware update mode.

2020.6.24: Yet another receiver upgrade.
The MC-1010 had had a hard life (I applied 3.3V 1.5A the wrong way on the supply) and I suspect not all is well with it. So it got replaced with the 'unicorn receiver' that never made it to production: MTK3339 based, but with the '155dB neighbour rejection' front end. Still running at 115200N81, and I suspect there is some SMM interrupt in the server causing the port to lose characters every few months, but now, at least, it is a known good receiver.

2020.5.28: Upgrade.
Server was running stratum 2 off of a local S1 for a few hours until I could verify that the GPSes were setup correctly.

2020.5.16: Receiver bug? Investigtion ongoing
Apparently the MC-1010 randomly gives out incorrect time, stepping 19 seconds out? Logging is enabled, and I have put in a bit of step-out protection code.

2020.4.26: Receiver bug
Note to future self: The MC-1010's output is all over the place in 1Hz mode. In 2Hz, 5Hz, and 10Hz mode it is fine.

2020.4.23: New receiver
Now running LocoSys MC-1010 and Skytraq Venus receivers.

2019.12.13: Server replacement
I replaced the hardware with something faster, more efficient, and with dual power supplies. At the same time, I forgot to put in the additional serial card for the GPS receivers, so at the moment the server is running off of a GPS receiver in the vault. It is getting a surprisingly good signal through 40cm of steel reinforced concrete and fire barrier.




Sky view
This is an intensity-graded plot of signal strength, seen both as the usual sky view, and as a south-centered cylindrical projection. Blue indicates that the satellite is excluded from the solution, red that the receiver has lost lock.