Comments on: Stratum 1 NTP, Garmin GPS 18 LVC on FreeBSD 8.0

By: Ryan Doyle

Ryan Doyle — Thu, 17 Jun 2010 03:07:03 +0000

Thanks for the info Joel, will amend the article.

Cheers
Ryan

By: Joel McClung

Joel McClung — Thu, 17 Jun 2010 02:34:20 +0000

To disconnect from the “cu” program, you need to type these three characters:

RETURN then tilde (~) then period (.)

A common mistake people make is to hit tilde dot without hitting RETURN first.

Thanks for the great writeup.

By: Rhys

Rhys — Mon, 10 May 2010 13:31:46 +0000

Well I’ve shifted it across to FreeBSD, brought back memories of just how bad Vi is to use,gave up on that, once nano was on, much easier

offset is reported as either -0.002, -0.001 or 0.000, with a jitter of 0.002. This is after maybe 20 minutes. I’ve half insulated the crystal as well, but I’d say the shift from winxp to freebsd made the biggest shift. I can’t see any way to improve this, as it can’t report an offset lower than 1us, and its not really moving around like it did on winxp.

Before I changed it, I managed to get the winxp out to 400us offset by opening a window and turning the fan on. Not exactly stable.

By: Ryan Doyle

Ryan Doyle — Tue, 04 May 2010 14:33:55 +0000

Hi Rhys, thanks for sharing this info and insights on the Windows platform.

By: Rhys

Rhys — Mon, 03 May 2010 09:28:10 +0000

Hi David,

My experience with Win7-64 was that with a standard minpoll of 64 seconds, it can barely stay synched (under 128ms) to a 1ms delay stratum 1. Off internet servers, it would run out past 128 and jump. Not sure how it would go with the PPS directly.

I’ve got a winxp box running with the PPS, and the win64 polling at 16 seconds can stay within +- 5 ms, but its reversing direction every 16 seconds for the clock.

The winxp box sits at +- 50 us of the PPS, heater coming on warms it up quicker than NTP can compensate, might insulate its crystal. Getting the PPS to work is a little strange as well, its nothing, nothing, nothing, then bang, starts working for some reason.

Thinking Atom box to replace the bulky winxp machine.

Rhys.

By: ryan

ryan — Wed, 21 Apr 2010 01:53:44 +0000

Hi David, I was wondering if you have got your Atom box up and running? I’m curious to know how it performs.

Cheers,
Ryan

By: David Taylor

David Taylor — Tue, 06 Apr 2010 14:46:08 +0000

Actually re spelling: British English (or even Scottish ). I’m just getting an Intel Atom powered box, and intend to try both Windows-7 and FreeBSD 8.0 as time server software (with FreeBSD 8.0 as the normal OS), so I’ll be referring to your notes.
The first step will be trying to get the box to dual-boot – I’m thinking of installing Windows-7 first, then FreeBSD 8.0.

Glad more folk found your note helpful.

David

By: rjcobain

rjcobain — Tue, 23 Mar 2010 21:09:36 +0000

Thanks, I managed to get an old coffee stained Thinkpad 600 running as a time server by following your instructions !

By: ryan

ryan — Mon, 01 Mar 2010 12:08:48 +0000

Hi Greg

Thanks for pointing that out! I had wired my port correctly, but mucked up the schematic. Fixed now

Ryan

By: Greg

Greg — Mon, 01 Mar 2010 01:59:12 +0000

Could you double check the DB9 wiring?
It’s backwards(tx/rx) from the original article and I found in my case the other article was correct (with a GPS18x)
Otherwise, great article, everything went to plan.
I have a nice little stratum 1 server on my old dell laptop.