[ntp:questions] Windows time question.
snews at lordynet.org
Tue May 3 11:58:01 UTC 2011
> In article <iou44b$q9o$1 at dont-email.me>, david-
> taylor at blueyonder.co.uk.invalid says...
>> "Rob" <nomail at example.com> wrote in message
>> news:slrnir54hp.hnj.nomail at xs8.xs4all.nl...
>>> The initial question:
>>> | Due to my wandering use of a laptop for, "work" (cough!) Often away
>>> | from the office, and our server, but with local internet access (Hotel
>>> | WiFi etc).
>>> | What UK based "RELIABLE" (cant emphasize that enough) UK time
>>> | would the group recomend I point Windows time sync' to?
>>> and the subsequent discussion about the NTP pool and its reliability,
>>> and how many servers from the pool one would resonably use to get good
>>> results without overloading a voluntarily provided service, is a good
>>> and valid discussion on its own.
>>> There is no need to pollute that discussion by talking about GPS
>>> yet again. It is not a solution for the original poster, and it does
>>> not contribute to the discussion about either of the topics brought up.
>>> You may be exited about your new GPS receiver toy, but there is no need
>>> to recommend that hammer as the only tool one will ever need. It isn't.
>> .. and why shouldn't someone consider taking a GPS 18x LVC as a portable
>> time reference?
> As the OP who started this (long and sometimes ammusing) thread...
> I do carry a GPS receiver with me, but sadly not PPS capable, I use it
> for location determination/tracking/navigating etc. Maybe I should
> include a GPS18 or 16 in the already bulging Laptop bag I lug arround.
> In any case, with most hotel's now, you can't open the windows (the ones
> in the outside wall of the room, not the OS!) enough, to get anything
> sensible outside to get a decent view of the sky. Many do not open at
> all, many are also now using "K Glass" that has a coating on it for
> thermal reasons, that appears to seriously attenuate GPS signals.
> I have also encountered problems many times with GPS RX's used for
> "normal satnav" purposes in the vicinity of some hotels, due I suspect
> to the *Huge* ammount of EM crap that seems to radiate from such
> establishments these days, in many, you cant even listen to FM radio in
> your room, let alone AM (or Shortwave for WWV etc!) So much for EMC
> regs eh?
> Even mobile phone signals are heavily attenuated (or spoiled?) "in
> room", leaving only the expensive hotel wifi network (if it's working)
> as a comm's route out... Not that mobile internet is any good for
> timekeeping! I think from the latencies I sometime see, they use
> moonbounce to get back to base....
> I have in one instance, had to use one of the "long range" BlueTooth
> adapters, to bt to a phone in the car, from a room (that luckily)
> overlooked the car park, to get any 'net conectivity. Naff latency, but
> I got my work done! I've also done the same trick, hoisting the phone
> some 50' up a mast in a plastic bag on a halyard (it was raining!) to
> get a signal on a remote customer site with no landline, then bt in
> remote sim mode to use the phone from the car! And that was just for a
> voice call!
> As earlier, the problem was a clash of interests between XP's own
> W32Time, and the National Instruments time discoverer/server, foisted on
> me by an update to other software (from our principle) that blindly and
> stupidly updates ALL of the NI installed tools and utilities, causing
> other problems too, not just the lockups.
> Now I've id'd the problem, I can work arround it. But as earlier, the
> info about the pool servers and (perhaps) not needing the location tags
> was good to know, though from what else I read, it's debatable if it
> will work reliably and predicably in practice for a traveling laptop.
Sometimes I use a notebook from a pub and am limited to using
mobile broadband dongle via usb port. Latency can be as high
as 10 seconds if ntp is used normally so I use 'burst' with a
couple of server lines in my ntp.conf which gets me within a
few milliseconds. The particular servers I abuse are my own.
I also have a GPS 18x-LVC but would have to use a serial2usb
adaptor which doesn't give me the few microsecond offset vs
PPS via real serial or parallel port and also it's difficult
to find a location that has good GPS reception so I don't
carry it with me. My larger notebooks have both serial and
parallel ports and are within a few microseconds when GPS is
> Thanks for the info and insight peeps.
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