[chris01]

There is frequent discussion here about how to synchronise your PC with internet time sources. For most purposes, remote NTP servers are OK but for real time nuts there's nothing quite like running your own stratum 1 server. It is now relatively cheap and not terribly difficult to achieve this. If you've spent hundreds or even thousands of <inset your currency unit here> on your HAQ watch(es) then a hundred <units> on a reference time source doesn't seem like a bad "investment".

Here's what you need:

1. A Raspberry Pi computer. This is a tiny unit that runs various versions of Linux, but you don't need any Linux knowledge for this task. Find a local supplier and get the B model and a suitable power supply. A case is a good idea, and you should find there's an 8GB SD card with a selection of OSes thrown in for a small extra cost. Total for me was £44. At the same time get a 4GB or larger blank SD card.

2. A GPS receiver that plugs directly into the Pi (Raspberry Pi GPS Addon Board),
together with an aerial (Active GPS Patch Antenna with SMA Connector). Total cost for me was £55.

3. Instructions: 5 minute guide to making an GPS synchronised NTP Server based on a Pi | Ava High Altitude Balloon Project Install the image on your blank 4GB card.

4. Connect the Pi to your network, with a fixed IP address and you have a stratum 1 time server. You can of course do lots of other stuff with the same computer but it's cheap enough to get another one! I run my music server on a Pi with an SSD drive - silent, with total power consumption 5 watts.

5. To set up your PC, it's a good idea to go to Meinberg's web site (Meinberg NTP Software Downloads)
and download an NTP installer (http://www.meinbergglobal.com/download/ntp/windows/[email protected])
and a monitor program (http://www.meinbergglobal.com/downl...erver-monitor/ntp-time-server-monitor-104.exe).

If you don't understand any of that, then I can't help you. If you're keen to try, and have any questions, I'll be happy to help, but please don't ask me about Linux!

 

[chris01]

If I were allowed to hang a GPS antenna outside my apartment I would be running a GPSDO.

Current GPS receivers seem very sensitive. We have foil/polyester sandwich insulation directly under our roof, so not much gets through that (and the CIA can't read our brainwaves). I have found, with both my Sure GPS and my Raspberry PI GPS, that the simple antennae work very well stuck on the inside of a north-facing second-storey window.

 

[chris01]

I tried with a earlier GPS watch to get synced inside my apartment near a window. It did not work. the Astron keeps trying and failing do to save power I put it in airplane mode.

These GPS watches don't seem very user-friendly at present. Judging by the negative comments from a few trusted contributors here, I'm glad I managed to resist the attraction of the new technology. I'll be waiting for a considerable size reduction, together with a big improvement in sensitivity, which seems a bit unlikely unless we can be persuaded to stick an external antenna on our hat.

 

[chris01]

Don't encourage them to put the antenna in the bracelet.

Agreed, this would be horrible. Probably wouldn't work too well if, like me, you insist on a steel or Ti bracelet. No, just run this cable under your shirt sleeve and plug it into the 2-foot high aerial on top of your head. I think I'll wait for a CSAC watch that only needs some batteries clipped to my belt.

For a non-autonomous highly accurate and zero-maintenance watch I think I'll be keeping my two Oceanus RCs for some time yet.