[time-nuts] NTP server using an OCXO, GPS chip and Raspberry Pi

[David J Taylor]

From: Andreas Kempe

Hello everyone,

I want to build an affordable quality time source for my computer
club. I've been toying with the idea of using an oven controlled
oscillator from Ebay for getting a reasonable (0,5 ppm frequency
stability) 1 PPS signal and a cheap GSP chip with UART for syncing the
time. I was thinking of running this on a Raspberry Pi with FreeBSD
and its gpiopps driver.

Is this a reasonable setup for an affordable NTP server?

Cordially,
Andreas Kempe
_______________________________________________

Andreas,

Here's an example of a simple device you can build:

  https://www.satsignal.eu/ntp/Raspberry-Pi-quickstart.html

It's quite temperature sensitive, so either put it where the temperature is 
stable, or use ntpheat to keep the CPU at a much more constant temperature:

  http://www.satsignal.eu/ntp/Raspberry-Pi-ntpheat.html

With those recommendations, and noting the delays in RPi I/O (at least in 
the earlier RPi cards where Ethernet is over USB), I would suggest that an 
OCXO is overkill.  No reason to deviate from the Raspbian OS.

You can gauge the performance from various Raspberry Pi devices here:

  http://www.satsignal.eu/mrtg/performance_ntp.php

Cheers,
David
-- 
SatSignal Software - Quality software for you
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Email: david-taylor at blueyonder.co.uk
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