Re: [time-nuts] Starting point for a WWVB project?
The Ultralink is spoken for. Thanks... 73, geo - n4ua On Tue, Jul 22, 2014 at 1:10 PM, George Dubovsky n4ua...@gmail.com wrote: While looking for something else in the basement, I found this Ultralink 301/333 WWVB receiver: https://plus.google.com/u/0/photos/116677848251094111716/albums/6038922880078010001 I think I picked it up because the case looked useful, but I haven't molested it. It does not seem to work and I can find limited documentation on it. The remote pod labeled 301 seems to be the entire receiver. It contains the ferrite-loaded antenna and a Temic U4226 receiver chip. The other box seems to be supporting and interface circuitry. I make no claims for the unit other than it's cute. I have no use for it. If someone wants a pig in a poke, $36 will get it Priority Mailed to you (domestic US only). Thanks. 73, geo - n4ua ___ 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] temperature sensor
On Tue, 22 Jul 2014 15:59:38 -0500 Bill Hawkins b...@iaxs.net wrote: There is plenty of literature on the subject, but it is not in the scope of precision time and frequency measurement. I would like to disagree here. Precise time and frequency measurement highly depends on precise control of temperature. Most of our devices and tools have a rather high temperature dependence (high for time-nuts needs ;-). Thus, i would like to ask you to share any good literature you have. I've been reading up on this topic the last two days, but merely scratched on the surface. Any pointer on good things to read would be highly appreciated. Attila Kinali -- I pity people who can't find laughter or at least some bit of amusement in the little doings of the day. I believe I could find something ridiculous even in the saddest moment, if necessary. It has nothing to do with being superficial. It's a matter of joy in life. -- Sophie Scholl ___ 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] new clock
it does need a different design, but a buried oscillator, 5 to 8 meter deep in the garden has the best temperature stabilization, just don't turn thee power off, but that could be done using the old Greek water-clock principle, the spill over stabilizer. In the Bay Area [California] the soil's temperature is around the year approximately 17C° ±0.01C° if you go further down it will be even more constant, without any heating power and control loop 73 KJ6UHN Alex On 7/22/2014 6:43 PM, Bob Camp wrote: Hi A lot depends on the oscillator. My fine old GR rack mount took most of 9 months to settle most of the way. It was still dropping in a year after that when I stopped watching it. Some of my T-Bolts took a week, some took a couple months…. Best thing you can do with any OCXO is just leave it on power. Bob On Jul 22, 2014, at 7:53 PM, paul swed paulsw...@gmail.com wrote: Agree with Marks comments. Regards Paul On Tue, Jul 22, 2014 at 5:25 PM, Mark Sims hol...@hotmail.com wrote: An oscillator can take many weeks to settle in after being powered off / shipped / abused / looked at cross-eyed / etc. It typically takes a Thunderbolt a month or two to settle down after being shipped from China. ___ 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. ___ 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. ___ 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. ___ 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] temperature sensor
To ensure that steam is in a suitable state for temperature measurement one uses a Hypsometer. I made one out of tin cans and it sits on an electric hot plate. It is not rocket science but it really works, my PT100 showed stable temperatures within a milliKelvin. It is made so that the splash is separated from the boiling water and the shielding surfaces are maintained at the wet steam temperature. All that is necessary in the design is that the pressure drop of the steam is kept below some reasonable number. The catch is that you must measure the ambient pressure to great precision, aneroid barometers are hardly good enough except for some specially calibrated devices, solid state barometric sensors are orders of magnitude too insensitive, and a mercury barometer (Fortin pattern) requires several calculated corrections including the exact value of gravity at the measurement site. cheers, Neville Michie On 23/07/2014, at 5:11 AM, Attila Kinali wrote: On Tue, 22 Jul 2014 01:17:03 +0100 Brian D gro...@planet3.freeuk.co.uk wrote: Saturated steam at standard pressure will be exactly 212F, or 100C. Stupid question: How to you ensure that the steam is saturated, while keeping a constant pressure? I think just buying some indium off ebay and use that as a melting/freezing reference is easier than the contraption needed to ensure fully saturated steam, with a low temperature gradient over the temperature sensor. That said. My investigations into stability of PT100 sensors reveal, that the quality ones can be less than 10mK/year, but hysteresis is in the same ball park (see [1]). Attila Kinali [1] Long term stability and hysteresis effects in Pt100 sensors used in industry, by Ljungblad, Holmstein, Josefson, Klevedal, 2013 -- I pity people who can't find laughter or at least some bit of amusement in the little doings of the day. I believe I could find something ridiculous even in the saddest moment, if necessary. It has nothing to do with being superficial. It's a matter of joy in life. -- Sophie Scholl ___ 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. ___ 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] new clock
Deep soil temperature stability is a bit of a myth, mainly because not many people actually measure it. I measured a beautiful 0.2C degree annual sine wave 15 metres down in limestone in Kentucky. The catch is the Gauss's Error function drop-off rate of temperature fluctuation is a very good low pass filter, so all the ambient noise of longer than a year period is not well attenuated. Secular variations, like a warm winter, a warmer than normal decade, all appear with less attenuation. 100 year functions reach 100 metres depth, and that does not count effects from percolating ground water. Admittedly a deep cellar made a good clock vault, but a thermistor, a computer fan and a 100 watt filament lamp in a wooden box can give far more accurate temperature control. cheers, Neville Michie On 23/07/2014, at 10:17 PM, Alexander Pummer wrote: it does need a different design, but a buried oscillator, 5 to 8 meter deep in the garden has the best temperature stabilization, just don't turn thee power off, but that could be done using the old Greek water-clock principle, the spill over stabilizer. In the Bay Area [California] the soil's temperature is around the year approximately 17C° ±0.01C° if you go further down it will be even more constant, without any heating power and control loop 73 KJ6UHN Alex On 7/22/2014 6:43 PM, Bob Camp wrote: Hi A lot depends on the oscillator. My fine old GR rack mount took most of 9 months to settle most of the way. It was still dropping in a year after that when I stopped watching it. Some of my T-Bolts took a week, some took a couple months…. Best thing you can do with any OCXO is just leave it on power. Bob On Jul 22, 2014, at 7:53 PM, paul swed paulsw...@gmail.com wrote: Agree with Marks comments. Regards Paul On Tue, Jul 22, 2014 at 5:25 PM, Mark Sims hol...@hotmail.com wrote: An oscillator can take many weeks to settle in after being powered off / shipped / abused / looked at cross-eyed / etc. It typically takes a Thunderbolt a month or two to settle down after being shipped from China. ___ 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. ___ 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. ___ 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. ___ 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. ___ 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] Synergy-GPS SSR-6tru Problem Resolved
As a reminder, I received an SSR-6tru receiver from Synergy, along with their M12 adapter, which allows you to plug it into a slot for an Oncore GT+, UT+, or VP. I was unable to get the receiver to respond to any commands from the u-blox u-center software. After a lot of troubleshooting, I discovered that pin-5, the DGPS IN pin, must be brought to a logic level high in order for this assembly to work. If it's low, apparently anything going into the board on the Rx line is simply sent back out on the Tx line and not passed to the receiver. I've never owned a GT+ or a VP, so I wasn't aware that a logic high was needed on this pin. The UT+ works just fine with this pin not connected. Bob ___ 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] temperature sensor
May I suggest thermistors and other temperature sensors made by Omega? http://www.omega.com/pptst/44000_THERMIS_ELEMENTS.html Their range of products is really large and prices are not too bad: http://www.omega.com/temperature/tsc.html take a look also to their literature: http://www.omega.com/techref/ _ Elio Corbolante. ___ 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] Synergy-GPS SSR-6tru Problem Resolved
Hi Bob, That's very good news. Thanks for following through on this issue. Newcomers to the list should know that unlike many of the large corporations in the TF business, Synergy has been hobbyist and time-nuts friendly since the beginning. I know a couple of us bought our first GPS receivers from Synergy in the mid-1990's. This was in the early days of GPS where we used Tom Clark's TAC h/w and SHOWTIME.EXE s/w, in the same way we use Trimble's Thunderbolt h/w and Mark/John's HEATHER.EXE s/w today. /tvb - Original Message - From: Bob Stewart b...@evoria.net To: Bob Stewart b...@evoria.net; Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Wednesday, July 23, 2014 3:19 PM Subject: Re: [time-nuts] Synergy-GPS SSR-6tru Problem Resolved As a reminder, I received an SSR-6tru receiver from Synergy, along with their M12 adapter, which allows you to plug it into a slot for an Oncore GT+, UT+, or VP. I was unable to get the receiver to respond to any commands from the u-blox u-center software. After a lot of troubleshooting, I discovered that pin-5, the DGPS IN pin, must be brought to a logic level high in order for this assembly to work. If it's low, apparently anything going into the board on the Rx line is simply sent back out on the Tx line and not passed to the receiver. I've never owned a GT+ or a VP, so I wasn't aware that a logic high was needed on this pin. The UT+ works just fine with this pin not connected. Bob ___ 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] Remoting a GPS Receiver
FYI: copies of Motorola Oncore chapter 5 are found here: http://www.ko4bb.com/manuals/index.php?dir=05)_GPS_Timing/Motorola_Oncore http://wa5rrn.com/Oncore%20GPS/ch5.pdf http://www.w8bapdstar.info/library/PrecisionClocking/Motorola%20Oncore/ /tvb - Original Message - From: Bob Stewart b...@evoria.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Wednesday, July 23, 2014 4:07 PM Subject: [time-nuts] Remoting a GPS Receiver There was a discussion recently about how to send the 1PPS from a receiver to a remote user. If this is duplicate information I apologize. Get a copy of the Motorola Oncore manuals and take a look at Chapter 5 where it discusses using RS-422 to do this. Simple schematics and timing information for setting up a remote GPS receiver are given. Bob - AE6RV ___ 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.
