On Fri, Aug 17, 2012 at 6:12 PM, Frank Hughes <[email protected]> wrote:
> So what I am trying to come up with now for home/shack is: > - An NTP server for our LAN > - A very high quality 10Mhz source to distribute to all the HP and Agilent > equipment here. Here is what I would do again,... 1) first get the NTP server running but use pool servers from the Internet as the reference clocks. Get this working well before you attempt to set up a GPS. But when you choose a computer make sure that it has an RS-232 serial port. Accuracy is more then an order of magnitude better then a USB hookup. It fack USB is so poor you can't take full advantage of GPS. I use an Intel Atom board. I got the one that uses a pasive heat sink and it only burns a very few watts. This matters becaue it runs 24x7. A big PC can cost $40 a month to run. The best OS to use is either BSD or Linux. These have order of magnitude better performance than others for this purpose 2) Find a place for a GPS antenna. It should be able to see to the horizon all 360 degrees. Well if you live in the USA some blockage to the North is OK. Put it on a short mast and as a ham you know about lightening and grounding and so on.. Don't skimp on that. 3/4 iron plumbing pipe with a pipe flange on top makes a perfect mast and you can run the cable down the pipe. Getting a good view of the entire sky helps a lot. Although it can work even just looking out a window. The 75 ohm double sheiled cable TV coax works well and is cheap. 3) Buy a Trimble Thunderbolt GPS from eBay. These are the best and easy to use and cost maybe $125. They produce a very good 10MHz output from an internal OCXO. They also have a one pulse per second output and of course serial rs-232 4) Finally connect Thunderbolt's PPS and serial data to the computer and edit the NTP config file to add the GPS. Keep the Internet pool servers. Chris Albertson Redondo Beach, California _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
