[time-nuts] Time servers on a well known web site.
Just found these on eBlag. Way outside my price range, but... 220445049656 Not sure if it actualy does GPS disiplined stuff, as there is no GPS antenna socket! 180370118043 Still too rich for me. And when you consider even a new NSLUG is about £65, and the GPS is not an expensive item either, plus the software is probably 'nix based. I hope the guy selling them, is whoever has worked out how to do that. I'd hate to think somone else has put a lot of time and effort into doing that, and is getting ripped off. Wonder too just how accurate it is, using a USB based (non PPS) GPS? Cheers All. Dave B G0WBX. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Time servers on a well known web site.
On Thu, Jul 9, 2009 at 7:17 AM, Dave Baxterd...@uk-ar.co.uk wrote: Just found these on eBlag. Way outside my price range, but... 220445049656 Not sure if it actualy does GPS disiplined stuff, as there is no GPS antenna socket! 180370118043 Still too rich for me. And when you consider even a new NSLUG is about £65, and the GPS is not an expensive item either, plus the software is probably 'nix based. did you notice that the demo site is called red herring - something is fishy about this whole setup. I hope the guy selling them, is whoever has worked out how to do that. I'd hate to think somone else has put a lot of time and effort into doing that, and is getting ripped off. Wonder too just how accurate it is, using a USB based (non PPS) GPS? From the product's webpage: The NTS1-GPS time source provides a time reference derived from the reception of NMEA data from the USB GPS receiver. It does not contain a pulse-per-second (PPS) kernel nor high-stability oscillators. The NTS1-GPS is not designed nor intended for use in application where high-precision high-stability UTC time is required. Position information is provided by the NTS1-GPS for reference only Cheers All. Dave B G0WBX. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- GDB has a 'break' feature; why doesn't it have 'fix' too? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Time servers on a well known web site.
Yes Chris, I did notice that. (red herring that is) But I also do know that many people do indeed put various flavours of Linux etc on the Slugs as they are known, for all sorts of odd purposes. So (subject to enough memory) I suspect they could do the job, somehow. What that was advertised to be, I have no doubt it can be done. Just as before, without the 1PPS input, the actual accuracy (as in +- mS of UTC) would not be good. But for an unconnected (to the outside world) network that doesnt need mS accuracy to UTC, they could provide an acceptable NTP source perhaps to keep a collection of file servers in sync, or to drive time of day displays. Some of the earlier Linksys WRTG routers are also popular targets for home brewed Linux based appliances, and there is also a lot of information about regarding hacking the hardware to include a real serial port too. (Seems, the only parts missing are the RS232 line drivers, and the 9way D socket!) It's a pity that the availability of the early versions that will run Linux etc, are becoming less common. With cheap second hand hardware like that about, with the right tools and information, I don't see it as impossible to re-purpose what was a Router, to be a GPS Disciplined NTP server, or anything else for that matter. People are already using them as Packet Radio (APRS) digipeaters Igates etc. Then there are the proliferation of single board router kits about, at has to be said a good cost with amazing processing capabilities, and fast network ports. Many interestingly from Eastern Europe! Any of them use a fraction of the power a PC needs. I did (out of curiosity) look up an early RFC regarding the NTP protocol itself. After my head had stopped spinning, I couldnt help wondering that with modern micro-controllers, some of which have open licensed TCP stacks available. One of them could do the job, subject to the software being brewed of course. As to the rack units, not a lot of use to me then, even if I could afford them. Me. I just need the time to mess with all this... At the moment, my ISP's NTP service seems to be ticking along OK, but I would not be suprised to see it to jump sideways again, at any time without warning, as they are currently restructuring their own network. Cheers All. Off home now. Dave B Message: 8 Date: Thu, 9 Jul 2009 09:54:12 -0600 From: Chris Kuethe chris.kue...@gmail.com Subject: Re: [time-nuts] Time servers on a well known web site. To: Discussion of precise time and frequency measurement time-nuts@febo.com Message-ID: 91981b3e0907090854v54af33d4v31fd6d184f3a...@mail.gmail.com Content-Type: text/plain; charset=ISO-8859-1 On Thu, Jul 9, 2009 at 7:17 AM, Dave Baxterd...@uk-ar.co.uk wrote: Just found these on eBlag. Way outside my price range, but... 220445049656 ? Not sure if it actualy does GPS disiplined stuff, as there is no GPS antenna socket! 180370118043 ? Still too rich for me. ?And when you consider even a new NSLUG is about ?65, and the GPS is not an expensive item either, plus the software is probably 'nix based. did you notice that the demo site is called red herring - something is fishy about this whole setup. I hope the guy selling them, is whoever has worked out how to do that. ? I'd hate to think somone else has put a lot of time and effort into doing that, and is getting ripped off. ? Wonder too just how accurate it is, using a USB based (non PPS) GPS? From the product's webpage: The NTS1-GPS time source provides a time reference derived from the reception of NMEA data from the USB GPS receiver. It does not contain a pulse-per-second (PPS) kernel nor high-stability oscillators. The NTS1-GPS is not designed nor intended for use in application where high-precision high-stability UTC time is required. Position information is provided by the NTS1-GPS for reference only Cheers All. Dave B G0WBX. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Time servers on a well known web site.
Some of the earlier Linksys WRTG routers are also popular targets for home brewed Linux based appliances, and there is also a lot of information about regarding hacking the hardware to include a real serial port too. (Seems, the only parts missing are the RS232 line drivers, and the 9way D socket!) It's a pity that the availability of the early versions that will run Linux etc, are becoming less common. Early WRT54G boxes had lots (relatively speaking) of RAM/ROM. To cut costs, Linksys switched from Linux to ??? and reduced the RAM. They now make a WRT54GL version that has more RAM. I assume they charge more for it, but I haven't checked prices. When I got one a couple of years ago, I paid the few extra $ in case I wanted to install non-standard software. I'm pretty sure the Linux hackers have managed to squeeze things into the smaller RAM of the newer boxes. Lots of info at http://en.wikipedia.org/wiki/WRT54GL -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Time servers on a well known web site.
Wonder too just how accurate it is, using a USB based (non PPS) GPS? The picture looked like a GlobalSat BU-353. I guess you could build a NTP server out one, but I wouldn't expect time-nuts quality. I've been looking for low cost GPS units that work well with NTP. I haven't found much. USB has a bad reputation for timing because it's polled, but that polling is done in hardware on the order of a ms. You can sanity check things by feeding a GPS with a serial connection to both a normal serial port and a RS-232 to USB gizmo. http://www.megapathdsl.net/~hmurray/ntp/GPS18LVC-usb-off.gif I think this says that USB works reasonably well and my kernel/whatever isn't getting the low-latency stuff right. The old non-x Garmin GPS-18-USB was pretty good. http://www.megapathdsl.net/~hmurray/ntp/GPS18USB-off.gif The 18-x is pretty bad. http://www.megapathdsl.net/~hmurray/ntp/GPS18LVCx-off.gif Most of the low cost USB units seem to use the SiRF chip sets. They are horrible for timing. http://www.megapathdsl.net/~hmurray/ntp/GPSSiRF-off.gif If anybody figures out how to get reasonable timing out of one of these things, please clue me in. -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Time servers on a well known web site.
Early WRT54G boxes had lots (relatively speaking) of RAM/ROM. To cut costs, Linksys switched from Linux to ??? and reduced the RAM. to VxWorks Regards, Javier -- Javier HerreroEMAIL: jherr...@hvsistemas.com HV Sistemas S.L. PHONE: +34 949 336 806 Los Charcones, 17AFAX: +34 949 336 792 19170 El Casar - Guadalajara - Spain WEB: http://www.hvsistemas.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Time servers on a well known web site.
Some of the earlier Linksys WRTG routers are also popular targets for home brewed Linux based appliances, and there is also a lot of information about regarding hacking the hardware to include a real serial port too. (Seems, the only parts missing are the RS232 line drivers, and the 9way D socket!) It's a pity that the availability of the early versions that will run Linux etc, are becoming less common. I'm pretty sure the Linux hackers have managed to squeeze things into the smaller RAM of the newer boxes. Lots of info at http://en.wikipedia.org/wiki/WRT54GL There is often a simple hardware hack available to get a (gnd, rx, tx) serial port on most router/nas/embedded appliances. I do not remember seeing any that had an input status pin. DCD (pin 1) is most often used. Thus lacking a good way to use a 1PPS, the serial interface might be beaten by a USB. We might be leaving time-nut territory wrt time accuracy anyway. -- Björn ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
