David Taylor wrote:
I have information on my Web site on the easy-to-use Sure GPS, as well
as the low-cost Garmin GPS 18x LVC.
http://www.satsignal.eu/ntp/Sure-GPS.htm
http://www.satsignal.eu/ntp/FreeBSD-GPS-PPS.htm
Mine are using simple puck antennas, indoors, on the top floor of a
two-storey building. Be aware that USB-connected devices will give far
less accuracy than serial-port connected ones, but may be adequate if
"half-a second" is all you need.
This summer I received two more SURE boards, it took about an hour total
to solder on the two required patch wires on each of them.
(I used David's pictures to remind me where to put the patch wires!)
Together with a pair of old laptops (with proper serial ports) this
gives me another set of Stratum1 servers, for a total outlay of less
than $100.
I've seen reports here that one of the timing nuts have measured the
SURE board as giving a PPS signal that's in the 25-50 ns range?
According to the loopstats files my laptop is mostly in the 3-500 ns
range, with excursions up to a us or two, obviously due to interrupt
response time jitter and temperature variations.
Terje
--
- <Terje.Mathisen at tmsw.no>
"almost all programming can be viewed as an exercise in caching"
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