"unruh" <un...@invalid.ca> wrote in message
news:cmQ1r.3572$py5.2...@newsfe09.iad...
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The graphs of the signal strengths at the edges of these dropouts is in
ftp://theory.physics.ubc.ca/outgoing/drop{out,in}.pdf
Could not access this page in Firefox.
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Is this a flaw in the Sure unit (NOte that the sure unit drops its PPS
signal as soon as it does not a fix. Some units-- Garmin?-- keep sending
out PPS based on the freerunning onboard clock for quite a while, as I
understand it.
Teh Sure does not, which may be an advantage or a disadvantage.
(ntpd/chrony grab one of the other servers which produces
discontinuities in time when the pps comes back)
Is it evidence of some outside noise source (jamming?) , microwave tower
emission?
That's certainly a possibility. I would try to locate the antenna so that
it has a clear view of at least half the sky, preferably towards the
south. You may also notice seasonal effects with foliage blocking the
signal more in spring and summer.
Mine have a moderate view of the sky, being located indoors, but on the
top floor of a domestic residence. Both pucks are stuck (magnetically) on
top of a PC, which does form a ground plane, but may also be a source of
electrical noise! I haven't monitored as you have, but I suspect I see
the effects of a drop-out perhaps once a fortnight.
Cheers,
David
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