[time-nuts] PC time app
David J Taylor
david-taylor at blueyonder.co.uk
Sat Nov 26 07:40:03 UTC 2011
From: "Hal Murray" <>
Sent: Saturday, November 26, 2011 6:58 AM
To: "Discussion of precise time and frequency measurement"
<time-nuts at febo.com>
Subject: Re: [time-nuts] PC time app
> david-taylor said:
>> Yes, although from some GPS devices the jitter may be worse than from
>> Internet servers (depending on your connection).
> I've been looking for "good", low cost GPS gizmos, preferably with no
> soldering required. If anybody finds one, please let me/us know.
> The best I've found is the Garmin GPS-18x. It is only "good" if you can
> the PPS signal and it requires some soldering.
> All the low cost GPS unit's I've tested have horrible jitter. They are
> crappy without PPS support.
I do agree with Hal's comments. The one other unit I've found is this
one, which I know I've mentioned here before:
but again some assembly is required, including soldering. It can take its
power from a spare USB port.
I did test the GPS 18(x) with a USB to serial adapter, and the PPS/DCD
line was passed through, allowing NTP to work rather better than pure LAN
sync, but not as good as a direct connection to the serial port DCD line.
Not all USB/serial adapters and their drivers work as well.
SatSignal software - quality software written to your requirements
Email: david-taylor at blueyonder.co.uk
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