Re: [time-nuts] Water on Enceladus - What does this imply about NASA'a ability to measure frequency?
One needs to know the carrier frequency. Must be a high quality reference for the Cassini transmitter. On 04/03/2014 08:17 PM, Chris Albertson wrote: I just read about a discovery of a liquid water ocean on Saturn's moon Enceladus. The method used was to measure the velocity of a spacecraft as it makes a close fly-by. Gravitational anomalies will cause the spacecraft to speed up or slow down as it flies over massive objects like mountains. With three pass they now have a 3 dimensional map of density distribution. It must be very sensitive if they can tell liquid water from ice by its gravitational field. (or even rock from ice) They say they can measure the spacecraft's velocity to 90 microns per second. They do this by measuring the Doppler sift of the transmitter.I've been trying to figure out what 90 microns/sec means in terms of frequency. But I think(?) I need to know the orbital velocity of Enceladus. -- Chuck Forsberg WA7KGX c...@omen.com www.omen.com Developer of Industrial ZMODEM(Tm) for Embedded Applications Omen Technology Inc The High Reliability Software 10255 NW Old Cornelius Pass Portland OR 97231 503-614-0430 ___ 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] Water on Enceladus - What does this imply about NASA'a ability to measure frequency?
Hi Back when they were designing this stuff, they were very interested in getting into the parts in 10 to the 15th. They didn’t get there, but that was the desire. Bob On Apr 4, 2014, at 2:17 AM, Chuck Forsberg WA7KGX c...@omen.com wrote: One needs to know the carrier frequency. Must be a high quality reference for the Cassini transmitter. On 04/03/2014 08:17 PM, Chris Albertson wrote: I just read about a discovery of a liquid water ocean on Saturn's moon Enceladus. The method used was to measure the velocity of a spacecraft as it makes a close fly-by. Gravitational anomalies will cause the spacecraft to speed up or slow down as it flies over massive objects like mountains. With three pass they now have a 3 dimensional map of density distribution. It must be very sensitive if they can tell liquid water from ice by its gravitational field. (or even rock from ice) They say they can measure the spacecraft's velocity to 90 microns per second. They do this by measuring the Doppler sift of the transmitter.I've been trying to figure out what 90 microns/sec means in terms of frequency. But I think(?) I need to know the orbital velocity of Enceladus. -- Chuck Forsberg WA7KGX c...@omen.com www.omen.com Developer of Industrial ZMODEM(Tm) for Embedded Applications Omen Technology Inc The High Reliability Software 10255 NW Old Cornelius Pass Portland OR 97231 503-614-0430 ___ 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] Water on Enceladus - What does this imply about NASA'a ability to measure frequency?
On 4/3/14 8:17 PM, Chris Albertson wrote: I just read about a discovery of a liquid water ocean on Saturn's moon Enceladus. The method used was to measure the velocity of a spacecraft as it makes a close fly-by. Gravitational anomalies will cause the spacecraft to speed up or slow down as it flies over massive objects like mountains. With three pass they now have a 3 dimensional map of density distribution. It must be very sensitive if they can tell liquid water from ice by its gravitational field. (or even rock from ice) They say they can measure the spacecraft's velocity to 90 microns per second. They do this by measuring the Doppler sift of the transmitter.I've been trying to figure out what 90 microns/sec means in terms of frequency. But I think(?) I need to know the orbital velocity of Enceladus. Ranging is done by looking at the round trip time from Earth to spacecraft back to Earth. The signal on the ground is generated by a hydrogen maser. The radio on the spacecraft adds Allan Deviation on the order of 1E-15 at tau of 100-1000 seconds. The uncertainties in things like the antenna and cables on the spacecraft add similar uncertainty. The ground station antenna also flexes and moves. I'd have to go look up what the magnitude of that is, but I think it's in the same order of magnitude. For Cassini (which is what they'd be doing for Enceladus), the signals are in the deep space X-band. Transmitted from earth at 7.15 GHz, returned from Cassini at 8.4 GHz (roughly). The ratio between transmitted and received signal is 880/749 (exactly). This is called the coherent turnaround ratio and we spend a fair amount of time making sure that the turnaround is phase coherent. That is, a phase shift of 1 radian on the input signal will result in a phase shift of 880/749 radians on the output signal. The actual time delay through the telecom system is measured on the ground before launch in a temperature chamber, so any temperature variation during the measurement can be accounted for. Radio science and navigation measurements are quite impressive in their accuracy and attention to detail. measuring range to cm (out of a billion km, i.e 1 part in 1E14) and velocity to mm/s is sort of standard. ___ 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] Water on Enceladus - What does this imply about NASA'a ability to measure frequency?
On 4/3/14 11:17 PM, Chuck Forsberg WA7KGX wrote: One needs to know the carrier frequency. Must be a high quality reference for the Cassini transmitter. Two way measurements are most likely here (although Cassini does carry a USO). So the downlink is locked to the uplink which comes from a maser. The design of the transmit and receive system to hold that performance all the way through the chain is a challenge. Interestingly, since the light time to Cassini is hours and hours, you need a *really* good clock on the ground, because you're comparing the phase of a signal you radiated several hours ago with the phase of the signal you are receiving now. To put this in perspective.. at a range of a bit more than billion km (one way) the light time is a bit less than 5000 seconds,or 10,000 seconds round trip. So there are 4.2E13 cycles of the down link signal between Saturn and Earth. The Allan Deviation is on the order of 1E-15, so we are typically measuring the phase of that signal to a few degrees. So, things like the physical temperature of the 70 meter DSN antenna make a difference. If the optical path is, say, 100 meters, and the temperature of the dish changes 1 degree C, what's the phase change? Well, steel has a CTE of about 13ppm/degree, and 13 ppm of 100 meters is about 1mm, which is about 10 degrees phase shift at 8.4 GHz (lambda = 36mm) Solid Earth tides also feature into this. I will point out that *measuring* the performance of the radio on the ground in the lab is quite a chore. You can easily see the air conditioner cycling on and off (that bump in Adev at 1000 seconds) and diurnal cycles in temperature. most of this affects things like the cables and connectors in the test setup. And woe to the rookie engineer who thinks they can make the measurements with any old signal generator from loan pool. ___ 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] New England Ham - Electronic Flea Market Dates * April * update]
Original Message Subject: [BARC-List] [Flea@MIT] New England Ham - Electronic Flea Market Dates * April * update From:New England Area Ham - Electronic Flea Market f...@mit.edu Date:Thu, April 3, 2014 3:05 pm To: f...@mit.edu -- New England Area Ham - Electronic Flea Market *** DATES *** 2014 P 1 of 2 All events are Ham Radio/ Electronic related except ~_~ *** 2014Contact Source ~~~ 6 Apr Framingham MA FARA @Keefe Tech $5@9 $25/T@7:30 Bev N1LOO 508 626 2012 + 12,13 Apr Wakefield MA Photographica @AmericalCtr ~photo~ John 781 592 2553 F 12 Apr Windsor CT VR+C Mus 115 Pierson LN @8AM Outdoor John 860 673 0518 12 Apr Montreal PQ MARC @StIgnatiusCh $5@9 $8/T@8:15 James 514 990 1965 W 13 Ap Manchester CT NEWS V/UHFConf @Baymount@8 I84x63 MarkK1MAP 413 566 8118 W+ 19 Apr S.Portland ME PAWA @AmLegion $6@8 $10/T@6:30 Bryce K1GAX 207 415 0498 W+ 20 Apr Cambridge MA FLEA at MITMitch 617 253 3776 F Third Sunday April thru October 26 Ap Gales Ferry CT RANSON Auction @FireHs $2@9Gary WT1SND 860 884 4218 W+ 26 Apr Brookline NH NEARC Antique $5@8:30 $10@7:30Bruce 603 772 7516 F+ 27 Ap Middletown NY OCARA @CommCtr $7@9 $12Sell Neil AC2O 914 490 2001 F 2,3 May Deerfield NH NEARfest XV @FG Mike K1TWF 978 250 1235 R 10 May E Greenbush NY EGARA @FireCo $6@8 $6/T@6 Tom KC2FCP 518 272 1494 W 18 May Cambridge MA FLEA at MITMitch 617 253 3776 F 31 May Goshen CT SBARC @FG Rt63 Marc K1CTT 860 672 2659 A+ 1 June Bethpage NY LIMARC @Briarcliffe Dave AK1NS 516 312 8745 A+ 7 June Hermon ME PSARA @8 @HS TG@6:30 Jerry K1GUP 207 848 3400 W 7 June Windsor CT VR+C Mus 115 Pierson LN @8AM Outdoor John 860 673 0518 8 June Queens NY HoSARC Stephen WB2KDG 718 898 5599 A+ *** LAST UPDATE 4-2-14 de W1GSL http://swapfest.usP 1 List is normally updated twice a month - look for the latest version *** Additions/ Corrections via e-Mail w1...@mit.edu - SUBSCRIBE US Mail W1GSL POB 397082 MIT Br Cambridge MA 02139 (c)2014 W1GSL unlimited reproduction permitted in entirety New England Area Ham - Electronic Flea Market *** DATES *** 2014 P2 of 2 *** 2014Contact Source ~~~ 15 June Cambridge MA FLEA at MITMitch 617 253 3776 F Third Sunday April thru October 21 June Newington CT NARL @StMarySch Quentin KB1EWM 860 383 8203 A+ 18,19 July Hartford CT ARRL Nat Conv 100th Anv. 860 594 0200 W 20 July Cambridge MA FLEA at MITMitch 617 253 3776 F 9 Aug Milo ME PARC @AmLegion George WA1JMM 207 441 6112 A+ 17 August Cambridge MAFLEA at MITMitch 617 253 3776 F 24 Aug Adams MA NoBARC @BoweFld $5@9 $10S@8 Eric KA1SUN 413 743 9975 F+ 6 Sept Windsor CT VR+C Mus 115 Pierson LN @8AM Outdoor John 860 673 0518 7 Sept Ballston Spa NY SCRACES @FG $10@7 Darlene N2XQG 518 587 2385 W+ 14 Sept Newtown CT CARA @TownHall$5@8:30 $10/TG $15/T Ron AB1RJ 203 938 7007 + 20 Sept Forestdale RI RIAFMRS @VFW $5/Sp@8 Pete AA1PL 401 639 4484 T 21 Sept Cambridge MA FLEA at MITMitch 617 253 3776 F 27 Sept Brookline NH NEARC Antique $5@8:30 $10@7:30 Bruce 603 772 7516 F+ 5 Oct Queens NY HoSARC Stephen WB2KDG 718 898 5599 W+ 10,11 Oct Deerfield NH NEARfest XVI @FG Mike K1TWF 978 250 1235 12 Oct Meriden CT Nutmeg @Sheraton was Wallingford John N1GNV 203 440 4973 18,19 Oct Wakefield MA Photographica @AmericalCtr ~photo~ John 781 592 2553 18 Oct Longueuil PQ CRA-RS $10/T@7 $7@9 Martin VE2DNF 405 466 2810 R+ 19 Oct Cambridge MA FLEA at MITMitch 617 253 3776 F 25 Oct Gales Ferry CT TCARC Auction @FireCo @10Darryl WA1DD 860 443 7799 T 26 Oct Hicksville NY LIMARC @Levittown HallRichie K2KNB 516 694 4937 A *** LAST UPDATE 4-2-14 de W1GSL http://swapfest.us P 2 of 2 List is
Re: [time-nuts] Water on Enceladus - What does this imply about NASA'a ability to measure frequency?
On 4/4/14 4:30 AM, Bob Camp wrote: Hi Back when they were designing this stuff, they were very interested in getting into the parts in 10 to the 15th. They didn’t get there, but that was the desire. Roughly that... http://lasp.colorado.edu/~horanyi/graduate_seminar/RSS.pdf is a good presentation with design and performance at a high level. It has plots of the USO and maser performance, etc. http://lasp.colorado.edu/~horanyi/graduate_seminar/Radio.pdf is a good paper describing Cassini Radio Science looking for Gravity waves. The Ka band system has some issues in flight. http://trs-new.jpl.nasa.gov/dspace/bitstream/2014/11139/1/02-3097.pdf gives some numbers.. see page 19 the DSN antenna is on the order of 1E-15 at tau=1000 seconds if you're careful, 1E-14 under normal operation Tropospheric scintillation is also a factor.. I doubt we will ever see a telecom subsystem as complex and sophisticated as Cassini's ever again. The modern trend is to less redundancy, and higher level of integration in the boxes so fewer total boxes. For the Juno mission on it's way to Jupiter, we were looking for the radio's contribution to the measurement uncertainty being around 4E-16 at 1000 seconds. https://www.youtube.com/watch?v=ulzq_mlU-fA is a high level explanation of the gravity science When the Deep Space Atomic Clock (a trapped Hg ion) flies, that will change a lot of radio science, because we will be able to make more accurate one-way measurements. They are hoping for an overall improvement of 2 orders of magnitude. ___ 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] Water on Enceladus - What does this imply about NASA'a ability to measure frequency?
Jim, Thanks for sharing the details and preventing this subject from turning into shared ignorance. Bill Hawkins ___ 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] Water on Enceladus - What does this imply about NASA'a ability to measure frequency?
On 4 Apr 2014 08:55, Tom Knox act...@hotmail.com wrote: 90 microns is approx a freq res of about 1 x 3.66 -12 Thomas Knox Since the Doppler shift is prortional to the frequency, I can't see how one can determine the absolute frequency. But given light travels at 3e8 m/s and they can resolve 9e-5 m/s, I would have thought that the frequency resolution needed was 9e-5/3e8=3e-13. We are differing by more than a factor of 10. Dave ___ 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] Water on Enceladus - What does this imply about NASA'a ability to measure frequency?
On 4/4/14 7:39 AM, Bill Hawkins wrote: Jim, Thanks for sharing the details and preventing this subject from turning into shared ignorance. It was working on this kind of thing that led me to time-nuts in the first place.. Deep Space nav is probably one of the most precise measurements made on a regular basis. How many other things are measured regularly to 1E-13 or 1E-14, as a day to day operational process (as opposed to laboratory experiments and the like). ___ 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] Water on Enceladus - What does this imply about NASA'a ability to measure frequency?
You are correct. I did most in my head late last night and kind of lost my focus as I was finishing. I was attempting to see roughly what timing accuracy was needed. I meant to end the sentence with a question mark. Thomas Knox Date: Fri, 4 Apr 2014 13:01:12 +0100 From: drkir...@gmail.com To: time-nuts@febo.com Subject: Re: [time-nuts] Water on Enceladus - What does this imply about NASA'a ability to measure frequency? On 4 Apr 2014 08:55, Tom Knox act...@hotmail.com wrote: 90 microns is approx a freq res of about 1 x 3.66 -12 Thomas Knox Since the Doppler shift is prortional to the frequency, I can't see how one can determine the absolute frequency. But given light travels at 3e8 m/s and they can resolve 9e-5 m/s, I would have thought that the frequency resolution needed was 9e-5/3e8=3e-13. We are differing by more than a factor of 10. Dave ___ 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] Water on Enceladus - What does this imply about NASA'a ability to measure frequency?
On 4/4/14 5:01 AM, Dr. David Kirkby wrote: On 4 Apr 2014 08:55, Tom Knox act...@hotmail.com wrote: 90 microns is approx a freq res of about 1 x 3.66 -12 Thomas Knox Since the Doppler shift is prortional to the frequency, I can't see how one can determine the absolute frequency. But given light travels at 3e8 m/s and they can resolve 9e-5 m/s, I would have thought that the frequency resolution needed was 9e-5/3e8=3e-13. We are differing by more than a factor of 10. It's actually even more tricky, if you think about it, because what you are really doing is making the measurement over some time period, and the path length of signal is continuously varying during that time. Not only is Cassini doing it's flyby of Enceladus (and you're looking for small deviations in trajectory from those due to an idealized point source masses), but you've also got your ground stations on Earth moving due to planetary motion, daily rotation, as well as things like solid earth tides moving the DSN station up and down by tens of cm during the measurements. Gravity science in deep space is a very time-nutty activity.. it's basically finding all the various sources of change, modeling them, and driving the uncertainties as low as possible. They use a collocated radiometer to compensate for the extra delay of the atmosphere of earth. JPL has all those folks computing earth rotation models, and that figures in (hey, you need to know the rotational velocity of earth pretty accurately, to take that out of the equation). The folks who do this spend a lot of time looking at residuals plots and trying to make them look like a flat line of zero width. ___ 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] Water on Enceladus - What does this imply about NASA'a ability to measure frequency?
On Fri, Apr 4, 2014 at 6:19 AM, Jim Lux jim...@earthlink.net wrote: Radio science and navigation measurements are quite impressive in their accuracy and attention to detail. measuring range to cm (out of a billion km, i.e 1 part in 1E14) and velocity to mm/s is sort of standard. Looks to be about one order of magnitude better than standard. They claimed 90 microns/sec velocity in this case. I was looking for a document that shows the design of the radio science system in the spacecraft but did not find it. Best I can tell is they use a phase locked receiver transmitter as a kind of transponder so the high precision clock is on Earth. They say this is the first time they are able to detect mechanical movement in the ground station antenna in the Doppler data. I guess 90 uM/sec sensitivity just about everything is a noise source. -- Chris Albertson Redondo Beach, California ___ 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] Water on Enceladus - What does this imply about NASA'a ability to measure frequency?
On 4/4/14 9:34 AM, Chris Albertson wrote: On Fri, Apr 4, 2014 at 6:19 AM, Jim Lux jim...@earthlink.net wrote: Radio science and navigation measurements are quite impressive in their accuracy and attention to detail. measuring range to cm (out of a billion km, i.e 1 part in 1E14) and velocity to mm/s is sort of standard. Looks to be about one order of magnitude better than standard. They claimed 90 microns/sec velocity in this case. I was looking for a document that shows the design of the radio science system in the spacecraft but did not find it. One of the links in the other message I posted has some of the links Best I can tell is they use a phase locked receiver transmitter as a kind of transponder so the high precision clock is on Earth. Exactly. Cassini carries a deep space transponder or DST, which is the predecessor of the Small Deep Space Transponder(SDST) which has been flying on most missions from JPL. APL has their version on Messenger (Mercury) and New Horizons (Pluto). The basic technique is to have a phase locked receiver with very narrow loop bandwidth (a few Hz) that locks to the uplink carrier. Traditionally that would be at around 9 MHz (called f0 in the coherent transponder world), and the receiver LO would be at 748 * f0, so the IF is at f0. That same oscillator is then multiplied up by 880 to generate the X band transmit signal. (hence the 880/749 ratio). S-band transponders use a similar scheme with 240/221 as the ratio. Early X-band radios used S-band designs with an added x4, just as many modern Ka-band radios use a x4 on the output of a Xband transmitter (e.g. Cassini is a X up/X down and X up/Ka-down system. the DST and SDST use DROs as the microwave oscillator. The SDST uses a VCXO that's around 80 MHz (8f0), but other than that, it's pretty much the same design approach. In the SDST, the carrier tracking loop and data demodulator is implemented in a digital ASIC which drives a DAC to control the VCXO. Newer coherent transponders do things a bit differently. They use the same stable XO, but then use a pair of NCO/DDSs to generate the reference oscillator for the multiplier/PLL for Rx and Tx. The tracking loop (and its filters) is implemented in digital hardware (FPGA). There's some cleverness in setting things up so spurs don't bite you, and that changes in the crystal frequency don't propagate through. By the way, for the best performance, you want to actually move the receiver LO to keep the signal at the same place in the IF, as opposed to doing some sort of block conversion and tracking entirely in software. That way, you don't worry about the phase vs frequency characteristic of the IF filters: you're always at the same place. All you have to worry about is phase vs temperature at one frequency. That said, the Electra UHF proximity radios use a LO that goes in big steps, so their coherent turnaround performance isn't as good (although, conceivably, one could characterize the IF group delay characteristics and build an equalizer in software) We're also going to GaAs VCOs because they have wider turning ranges. Historically, transponders are made in extremely limited quantities (3-4 units every few years) and they have a lot of touch labor for tuning (e.g. you get your frequency assignment years in advance, and you order crystals at the right frequency, etc.). There's a fair amount of reuse of spare transponders (e.g. a mission which is flying 1 or 2 will buy an extra, and then when they successfully launch, will hand off that spare to the next mission) which leads to all sorts of channel assignment issues (Opportunity and MRO have the same DSN channel, for instance), so there's been interest in designs which can have their channel selected after manufacturing. DROs don't have the tuning range to cover the whole 50MHz X-band, and certainly not the 500 MHz Ka-band. We spent a couple years trying to make a dual control input DRO with a coarse and fine inputs, but it didn't work out so well. As readers of this list will appreciate, a quiet oscillator has high Q resonators, and that is the opposite of what you want for wide tuning range. We developed some prototypes using GaAs VCOs whcih seem to work quite well, and that's the direction we'll probably go in the future. Personally, I will be happy if I never have to fool with making DROs again. High performance DROs are the epitome of touch labor, and being basically a mechanical resonator, have microphonics, temperature coefficients, picky alignment during assembly, etc.. A monolithic solution which uses lithography is FAR better, if you can get it to work. They say this is the first time they are able to detect mechanical movement in the ground station antenna in the Doppler data. Yes. they've made a big effort to do this in preparation for Juno (and Bepi-Colombo) because they're trying to push the radio/gravity science
Re: [time-nuts] Water on Enceladus - What does this imply about NASA'a ability to measure frequency?
gravitation measurement, particularly gravitation measurement in space is based on the Eotvos -effect see here: http://en.wikipedia.org/wiki/E%C3%B6tv%C3%B6s_effect and here: http://en.wikipedia.org/wiki/Lor%C3%A1nd_E%C3%B6tv%C3%B6sand from the begin of the space exploration many space crafts using accelerometer based on that Eotvos pendulum, invented by Eotvos in the eighteen-hundreds [the richest oilfields in the United States were discovered by Eötvös' Pendulum. The Eötvös pendulum was used to prove the equivalence of the inertial mass http://en.wikipedia.org/wiki/Inertial_mass and the gravitational mass http://en.wikipedia.org/wiki/Gravitational_mass accurately] so no speed no time measurement is necessary... ~ a former co-worker of space projects. A. Pummer On 4/4/2014 9:01 AM, Jim Lux wrote: On 4/4/14 5:01 AM, Dr. David Kirkby wrote: On 4 Apr 2014 08:55, Tom Knox act...@hotmail.com wrote: 90 microns is approx a freq res of about 1 x 3.66 -12 Thomas Knox Since the Doppler shift is prortional to the frequency, I can't see how one can determine the absolute frequency. But given light travels at 3e8 m/s and they can resolve 9e-5 m/s, I would have thought that the frequency resolution needed was 9e-5/3e8=3e-13. We are differing by more than a factor of 10. It's actually even more tricky, if you think about it, because what you are really doing is making the measurement over some time period, and the path length of signal is continuously varying during that time. Not only is Cassini doing it's flyby of Enceladus (and you're looking for small deviations in trajectory from those due to an idealized point source masses), but you've also got your ground stations on Earth moving due to planetary motion, daily rotation, as well as things like solid earth tides moving the DSN station up and down by tens of cm during the measurements. Gravity science in deep space is a very time-nutty activity.. it's basically finding all the various sources of change, modeling them, and driving the uncertainties as low as possible. They use a collocated radiometer to compensate for the extra delay of the atmosphere of earth. JPL has all those folks computing earth rotation models, and that figures in (hey, you need to know the rotational velocity of earth pretty accurately, to take that out of the equation). The folks who do this spend a lot of time looking at residuals plots and trying to make them look like a flat line of zero width. ___ 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] Water on Enceladus - What does this imply about NASA'a ability to measure frequency?
On 4/4/14 9:58 AM, Alex Pummer wrote: gravitation measurement, particularly gravitation measurement in space is based on the Eotvos -effect see here: http://en.wikipedia.org/wiki/E%C3%B6tv%C3%B6s_effect and here: http://en.wikipedia.org/wiki/Lor%C3%A1nd_E%C3%B6tv%C3%B6sand from the begin of the space exploration many space crafts using accelerometer based on that Eotvos pendulum, invented by Eotvos in the eighteen-hundreds [the richest oilfields in the United States were discovered by Eötvös' Pendulum. The Eötvös pendulum was used to prove the equivalence of the inertial mass http://en.wikipedia.org/wiki/Inertial_mass and the gravitational mass http://en.wikipedia.org/wiki/Gravitational_mass accurately] so no speed no time measurement is necessary... ~ a former co-worker of space projects. A. Pummer I don't know many spacecraft that carry a gravity sensor these days. Apollo 17 carried a gravimeter based on a vibrating string accelerometer. There's a proposed experiment for 2017 or something to do the equivalence test. There's also a proposal to put a spring gravimeter (ISA) on an ESA lunar lander, and to include it in the proposed MAGIA mission, which uses the two satellite GRAIL/GRACE approach as the primary measurement. I think Bepi-Colombo is carrying the Italian Spring Accelerometer to Mercury. GRAIL and GRACE measure the distance between two spacecraft very precisely (using carrier phase measurements on board) to infer the gravitational field of the body they are orbiting around. Gravity science by measuring range and Doppler is popular because it's cheap. You already have to have a radio on the spacecraft, so the incremental cost for the science is the labor of the toilers on the ground, who can be inexpensive graduate students working on their dissertation in non-real time. There *is* a cost to specifying and measuring the performance of the spacecraft radio to support this kind of precision, but that again, is just a cost penalty and it's small. It doesn't add risk, mass, or power. Adding an instrument adds mass, power, data bandwidth and programmatic risk (what if the instrument isn't delivered on time, or interferes with some other instrument or the spacecraft). Radio science adds no mass, no power is required and the data is entirely gathered on the ground, where it's cheap. There is a slight operational cost: doing an 8 hour gravity science pass with the data rate turned down to minimum so you can have maximum power in the carrier, as opposed to in the data sidebands. And, this is changing. As we move towards faster telecom radios, keeping good radio science performance is challenging. When we sent bits at 10 bits/second, you needed really good close in phase noise, and so, the radio science performance came for free. But when you send 10 Mbps, the phase noise inside 10 Hz isn't as big a deal, and people are starting to ask why are we spending extra time, money, mass, risk to achieve insanely high radio science performance... That's why Bill Folkner led a development effort to develop a purpose specific low mass, low power radio science instrument (RSTI). A 1kg, few Watt, 1 liter box that you could put on anything to do precision radio science (and nothing else). The prototype is (hopefully) going to fly as part of LMRST, which is a 2 or 3U cubesat. ___ 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] Acam TDC's
Hi, With all the recent talk of interpolators, I started looking at the acam TDC chips again - the GP22 is pretty cheap now for anyone who's up for playing with the tiny QFN package. I was wondering if anyone here has tried them or properly evaluated them as a TIC - especially the GP2/GP21/GP22. A few years back a some folk were talking about it, but I did not hear much since that. Angus. ___ 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] Acam TDC's
Angus An interesting chip. I had never heard of it before and suspect this may be the gizmo used in closed system water leak detection. Won't go into why I know about that. I did find comments from 2007 about the chip and atmega but nothing since. When I went looking for distributors or pricing to get an idea came up empty. Though Amazon will sell you lots of vitamins or something called TDC. So with all that said I will guess that for time-nuts purposes the capabilities of this chip have been far exceeded by the various array technologies we have at very cheap prices today. The ability to create long counters at very high speeds. Only a guess though. Regards Paul. WB8TSL On Fri, Apr 4, 2014 at 5:35 PM, Angus not.ag...@btinternet.com wrote: Hi, With all the recent talk of interpolators, I started looking at the acam TDC chips again - the GP22 is pretty cheap now for anyone who's up for playing with the tiny QFN package. I was wondering if anyone here has tried them or properly evaluated them as a TIC - especially the GP2/GP21/GP22. A few years back a some folk were talking about it, but I did not hear much since that. Angus. ___ 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] new GPSDO kit
Hello everyone, sorry for the plug, but we just announced a new $568 complete GPSDO reference kit. This unit is a tiny desktop unit with 10m antenna, power supply, cables, CD, and other accessories. It is a low cost addition to our Fury GPSDO line, and contains a really good TCXO, a uBlox GPS receiver, and various power options. I believe this is the lowest-cost real GPSDO in mass production available on the market right now, and being a true GPSDO it has some fairly good phase noise and stability specs. http://www.jackson-labs.com/assets/uploads/main/LC-XO-Plus_PressRelease.pdf bye, Said ___ 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 GPSDO kit
If you are going to plug the unit re time nuts, how about a price break for said group? Michael On Fri, Apr 4, 2014 at 3:39 PM, saidj...@aol.com wrote: Hello everyone, sorry for the plug, but we just announced a new $568 complete GPSDO reference kit. This unit is a tiny desktop unit with 10m antenna, power supply, cables, CD, and other accessories. It is a low cost addition to our Fury GPSDO line, and contains a really good TCXO, a uBlox GPS receiver, and various power options. I believe this is the lowest-cost real GPSDO in mass production available on the market right now, and being a true GPSDO it has some fairly good phase noise and stability specs. http://www.jackson-labs.com/assets/uploads/main/LC-XO-Plus_PressRelease.pdf bye, Said ___ 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 GPSDO kit
Michael, I was able to get a $50 Time-Nuts discount from the marketing guys.. Just mention $50 time nuts discount.. Bye, Said Sent From iPhone On Apr 4, 2014, at 15:58, Michael Perrett mkperr...@gmail.com wrote: If you are going to plug the unit re time nuts, how about a price break for said group? Michael On Fri, Apr 4, 2014 at 3:39 PM, saidj...@aol.com wrote: Hello everyone, sorry for the plug, but we just announced a new $568 complete GPSDO reference kit. This unit is a tiny desktop unit with 10m antenna, power supply, cables, CD, and other accessories. It is a low cost addition to our Fury GPSDO line, and contains a really good TCXO, a uBlox GPS receiver, and various power options. I believe this is the lowest-cost real GPSDO in mass production available on the market right now, and being a true GPSDO it has some fairly good phase noise and stability specs. http://www.jackson-labs.com/assets/uploads/main/LC-XO-Plus_PressRelease.pdf bye, Said ___ 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] new GPSDO kit
Hi Said: Can you say more about what this means? It generates a low-noise 10MHz signal with typically better than 1E-010 precision and accuracy (0.1ppb) on average Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html saidj...@aol.com wrote: Hello everyone, sorry for the plug, but we just announced a new $568 complete GPSDO reference kit. This unit is a tiny desktop unit with 10m antenna, power supply, cables, CD, and other accessories. It is a low cost addition to our Fury GPSDO line, and contains a really good TCXO, a uBlox GPS receiver, and various power options. I believe this is the lowest-cost real GPSDO in mass production available on the market right now, and being a true GPSDO it has some fairly good phase noise and stability specs. http://www.jackson-labs.com/assets/uploads/main/LC-XO-Plus_PressRelease.pdf bye, Said ___ 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 GPSDO kit
On 4 Apr 2014 23:39, saidj...@aol.com wrote: Hello everyone, sorry for the plug, but we just announced a new $568 complete GPSDO reference kit. Given the low power consumption I assume that this doesn't use an oven. That means if it does lose GPS lock, the frequency is going to drift much faster than other units. Or does it stop producing 10 MHz if it loses lock? ___ 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] M12+T module questions
Received my M12+T and would like to gather parts to get it running and tested. I've looked through the manual for a battery type description and couldn't find one. Anyone know of a part number for the onboard battery I could reference? Also looking for a mating cable/connector for the 10pin header. Thanks Jim ab3cv ___ 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 GPSDO kit
Wow. Seriously I was just going to post about my $35 GPSDO. I've used some discipline to not say for just a little more I can get... and gone the lowest cost route at each decision point. Just to see what happens. Price does not include GPS receiver, plug-in power cube and case and I'm not shooting for really great spec's. My goal was lowest price possible. The unit is based on the one posted here by Lars Walenius. I replaced his $30 Arudino with a $4 part and added an LCD display. It's not finished yet. I plan on changing out the LCD display to a $4 Nokia cell phone part that does 84x84 pixel graphics. I'd like to have the GPSDO do its own primitive graphs and setup menus without need to be connected to a computer. No intent to compete with a commercial product. I'm not going to sell them. But in time I'll document it. Here is a photo https://www.dropbox.com/s/bsksw9x51ydk6gi/gpsdo.jpg On Fri, Apr 4, 2014 at 3:39 PM, saidj...@aol.com wrote: Hello everyone, sorry for the plug, but we just announced a new $568 complete GPSDO reference kit. This unit is a tiny desktop unit with 10m antenna, power supply, cables, CD, and other accessories. It is a low cost addition to our Fury GPSDO line, and contains a really good TCXO, a uBlox GPS receiver, and various power options. I believe this is the lowest-cost real GPSDO in mass production available on the market right now, and being a true GPSDO it has some fairly good phase noise and stability specs. http://www.jackson-labs.com/assets/uploads/main/LC-XO-Plus_PressRelease.pdf bye, Said ___ 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. -- Chris Albertson Redondo Beach, California ___ 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 GPSDO kit
I mean no disrespect to anyone here. Jacksonlabs makes some very fine components. Brookes comment was spot on. What happens etc. I did run out to the site and take a quick read. The short piece I read did not have a lot of specifics or I simply missed them. It is low power and thats quite a plus, but has to also take into account how it behaves without GPS. Hopefully others will comment. So looking at the price I know that I have seen used Tbolts all over the place up to at least $350 or more. Same for the HPs and they have lots of miles on them. I suspect some comparison to those technologies would be helpful in appreciating whats being offered. Look at the fast turn around Said did. A time-nut says how about a discount and there you go a discount. Regards Paul WB8TSL On Fri, Apr 4, 2014 at 8:20 PM, Chris Albertson albertson.ch...@gmail.comwrote: Wow. Seriously I was just going to post about my $35 GPSDO. I've used some discipline to not say for just a little more I can get... and gone the lowest cost route at each decision point. Just to see what happens. Price does not include GPS receiver, plug-in power cube and case and I'm not shooting for really great spec's. My goal was lowest price possible. The unit is based on the one posted here by Lars Walenius. I replaced his $30 Arudino with a $4 part and added an LCD display. It's not finished yet. I plan on changing out the LCD display to a $4 Nokia cell phone part that does 84x84 pixel graphics. I'd like to have the GPSDO do its own primitive graphs and setup menus without need to be connected to a computer. No intent to compete with a commercial product. I'm not going to sell them. But in time I'll document it. Here is a photo https://www.dropbox.com/s/bsksw9x51ydk6gi/gpsdo.jpg On Fri, Apr 4, 2014 at 3:39 PM, saidj...@aol.com wrote: Hello everyone, sorry for the plug, but we just announced a new $568 complete GPSDO reference kit. This unit is a tiny desktop unit with 10m antenna, power supply, cables, CD, and other accessories. It is a low cost addition to our Fury GPSDO line, and contains a really good TCXO, a uBlox GPS receiver, and various power options. I believe this is the lowest-cost real GPSDO in mass production available on the market right now, and being a true GPSDO it has some fairly good phase noise and stability specs. http://www.jackson-labs.com/assets/uploads/main/LC-XO-Plus_PressRelease.pdf bye, Said ___ 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. -- Chris Albertson Redondo Beach, California ___ 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] new GPSDO kit
Check out the semi-Arduino + OLED LCD that Sparkfun will be selling soon... it's tiny, fairly cheap, and can run on 3.3 to 18 volts. Looks like it will be very useful for a lot of small projects. Unfortunately, the OLED does not appear to have a touch screen. https://www.sparkfun.com/news/1445 I plan on changing out the LCD display to a $4 Nokia cell phone part that does 84x84 pixel graphics. I'd like to have the GPSDO do its own primitive graphs and setup menus without need to be connected to a computer. ___ 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] M12+T module questions
Jim, Can't help you with the on-board battery as my M12+T's were the optional external battery types. But as for the connector, I got both PCB-mount and IDC-type cable assemblies as free samples from Samtec. Can't seem to find the part numbers at the moment but can dig for them if you need. Their catalog is on-line. Regards, Brent On Apr 4, 2014, at 19:00, Jim Miller j...@jtmiller.com wrote: Received my M12+T and would like to gather parts to get it running and tested. I've looked through the manual for a battery type description and couldn't find one. Anyone know of a part number for the onboard battery I could reference? Also looking for a mating cable/connector for the 10pin header. Thanks Jim ab3cv ___ 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 GPSDO kit
Hi guys, Let me try to answer the questions. This unit is placed to fill a need for lower cost plug-and-play units than what our Fury offers. The Fury desktop DOCXO sells for around $1700 if I am not mistaken, and literally 100's of them are sold every year. This is not trying to address a $50 hobbyist market; heck we pay about $50 just for the front and rear panels because we make them in the US in small qty instead of ordering 10,000 from China at $0.75 each. There are other options at that price point on EBay, for example you can get a complete 58503A kit for $550 now which I consider one of the best units ever -way better than any Thunderbolt I have seen, and I have said so many times here in the past. We however need to worry about paying salaries and the PL statements at the end of the year, so we have to price products at cost * x unfortunately. The unit works well for typical lab applications, and if the loop time constants are increased a bit and the Unit is shielded from airflow, the ADEV is quite good, around xE-010 or better is possible. It's also easier to deploy than the Fury, no user-interaction is needed other than applying power and connecting the antenna. This not being an oven as noted, it really is not designed for holdover. But how often does one see GPS holdover in a stationary lab application with uBlox GPS receivers? We have the Fury for that. The Phase noise and ADEV of the Fury are also significantly better of course.. Buying used equipment works really well to keep cost down, but for those that have to buy new with support, warranty, and a long life-cycle there are no other desktop GPSDO kits with complete accessories available in this price range that I am aware of. Of course if there are, I would like to hear about them.. Bye, Said Sent from my iPad On Apr 4, 2014, at 17:45, paul swed paulsw...@gmail.com wrote: I mean no disrespect to anyone here. Jacksonlabs makes some very fine components. Brookes comment was spot on. What happens etc. I did run out to the site and take a quick read. The short piece I read did not have a lot of specifics or I simply missed them. It is low power and thats quite a plus, but has to also take into account how it behaves without GPS. Hopefully others will comment. So looking at the price I know that I have seen used Tbolts all over the place up to at least $350 or more. Same for the HPs and they have lots of miles on them. I suspect some comparison to those technologies would be helpful in appreciating whats being offered. Look at the fast turn around Said did. A time-nut says how about a discount and there you go a discount. Regards Paul WB8TSL On Fri, Apr 4, 2014 at 8:20 PM, Chris Albertson albertson.ch...@gmail.comwrote: Wow. Seriously I was just going to post about my $35 GPSDO. I've used some discipline to not say for just a little more I can get... and gone the lowest cost route at each decision point. Just to see what happens. Price does not include GPS receiver, plug-in power cube and case and I'm not shooting for really great spec's. My goal was lowest price possible. The unit is based on the one posted here by Lars Walenius. I replaced his $30 Arudino with a $4 part and added an LCD display. It's not finished yet. I plan on changing out the LCD display to a $4 Nokia cell phone part that does 84x84 pixel graphics. I'd like to have the GPSDO do its own primitive graphs and setup menus without need to be connected to a computer. No intent to compete with a commercial product. I'm not going to sell them. But in time I'll document it. Here is a photo https://www.dropbox.com/s/bsksw9x51ydk6gi/gpsdo.jpg On Fri, Apr 4, 2014 at 3:39 PM, saidj...@aol.com wrote: Hello everyone, sorry for the plug, but we just announced a new $568 complete GPSDO reference kit. This unit is a tiny desktop unit with 10m antenna, power supply, cables, CD, and other accessories. It is a low cost addition to our Fury GPSDO line, and contains a really good TCXO, a uBlox GPS receiver, and various power options. I believe this is the lowest-cost real GPSDO in mass production available on the market right now, and being a true GPSDO it has some fairly good phase noise and stability specs. http://www.jackson-labs.com/assets/uploads/main/LC-XO-Plus_PressRelease.pdf bye, Said ___ 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. -- Chris Albertson Redondo Beach, California ___ 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
Re: [time-nuts] new GPSDO kit
Paul, Forgot to mention, there is a spec sheet on the website on the LC-XO-Plus product page with additional technical details. Bye, Said Sent from my iPad On Apr 4, 2014, at 17:45, paul swed paulsw...@gmail.com wrote: I mean no disrespect to anyone here. Jacksonlabs makes some very fine components. Brookes comment was spot on. What happens etc. I did run out to the site and take a quick read. The short piece I read did not have a lot of specifics or I simply missed them. It is low power and thats quite a plus, but has to also take into account how it behaves without GPS. Hopefully others will comment. So looking at the price I know that I have seen used Tbolts all over the place up to at least $350 or more. Same for the HPs and they have lots of miles on them. I suspect some comparison to those technologies would be helpful in appreciating whats being offered. Look at the fast turn around Said did. A time-nut says how about a discount and there you go a discount. Regards Paul WB8TSL On Fri, Apr 4, 2014 at 8:20 PM, Chris Albertson albertson.ch...@gmail.comwrote: Wow. Seriously I was just going to post about my $35 GPSDO. I've used some discipline to not say for just a little more I can get... and gone the lowest cost route at each decision point. Just to see what happens. Price does not include GPS receiver, plug-in power cube and case and I'm not shooting for really great spec's. My goal was lowest price possible. The unit is based on the one posted here by Lars Walenius. I replaced his $30 Arudino with a $4 part and added an LCD display. It's not finished yet. I plan on changing out the LCD display to a $4 Nokia cell phone part that does 84x84 pixel graphics. I'd like to have the GPSDO do its own primitive graphs and setup menus without need to be connected to a computer. No intent to compete with a commercial product. I'm not going to sell them. But in time I'll document it. Here is a photo https://www.dropbox.com/s/bsksw9x51ydk6gi/gpsdo.jpg On Fri, Apr 4, 2014 at 3:39 PM, saidj...@aol.com wrote: Hello everyone, sorry for the plug, but we just announced a new $568 complete GPSDO reference kit. This unit is a tiny desktop unit with 10m antenna, power supply, cables, CD, and other accessories. It is a low cost addition to our Fury GPSDO line, and contains a really good TCXO, a uBlox GPS receiver, and various power options. I believe this is the lowest-cost real GPSDO in mass production available on the market right now, and being a true GPSDO it has some fairly good phase noise and stability specs. http://www.jackson-labs.com/assets/uploads/main/LC-XO-Plus_PressRelease.pdf bye, Said ___ 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. -- Chris Albertson Redondo Beach, California ___ 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] M12+T module questions
The data connector is a standard 0.05 inch double row of male headers. These are common but not nearly so common as the 0.1 type. I used a 2032 coin cell battery and holder I un-soldered from an dead PC motherboard. Even a coin cell will last its shelf life at least. You will need to level shift the serial data to/from the MT12 if you want to connect it to a PC. On Fri, Apr 4, 2014 at 4:53 PM, Jim Miller j...@jtmiller.com wrote: Received my M12+T and would like to gather parts to get it running and tested. I've looked through the manual for a battery type description and couldn't find one. Anyone know of a part number for the onboard battery I could reference? Also looking for a mating cable/connector for the 10pin header. Thanks Jim ab3cv ___ 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. -- Chris Albertson Redondo Beach, California ___ 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 GPSDO kit
Said, I looked through the literature on your website, but didn't see any pictures of the inside of the unit. I'm curious to see the board and component compliment. Regards, Brent On Apr 4, 2014, at 20:19, Said Jackson saidj...@aol.com wrote: Paul, Forgot to mention, there is a spec sheet on the website on the LC-XO-Plus product page with additional technical details. Bye, Said Sent from my iPad On Apr 4, 2014, at 17:45, paul swed paulsw...@gmail.com wrote: I mean no disrespect to anyone here. Jacksonlabs makes some very fine components. Brookes comment was spot on. What happens etc. I did run out to the site and take a quick read. The short piece I read did not have a lot of specifics or I simply missed them. It is low power and thats quite a plus, but has to also take into account how it behaves without GPS. Hopefully others will comment. So looking at the price I know that I have seen used Tbolts all over the place up to at least $350 or more. Same for the HPs and they have lots of miles on them. I suspect some comparison to those technologies would be helpful in appreciating whats being offered. Look at the fast turn around Said did. A time-nut says how about a discount and there you go a discount. Regards Paul WB8TSL On Fri, Apr 4, 2014 at 8:20 PM, Chris Albertson albertson.ch...@gmail.comwrote: Wow. Seriously I was just going to post about my $35 GPSDO. I've used some discipline to not say for just a little more I can get... and gone the lowest cost route at each decision point. Just to see what happens. Price does not include GPS receiver, plug-in power cube and case and I'm not shooting for really great spec's. My goal was lowest price possible. The unit is based on the one posted here by Lars Walenius. I replaced his $30 Arudino with a $4 part and added an LCD display. It's not finished yet. I plan on changing out the LCD display to a $4 Nokia cell phone part that does 84x84 pixel graphics. I'd like to have the GPSDO do its own primitive graphs and setup menus without need to be connected to a computer. No intent to compete with a commercial product. I'm not going to sell them. But in time I'll document it. Here is a photo https://www.dropbox.com/s/bsksw9x51ydk6gi/gpsdo.jpg On Fri, Apr 4, 2014 at 3:39 PM, saidj...@aol.com wrote: Hello everyone, sorry for the plug, but we just announced a new $568 complete GPSDO reference kit. This unit is a tiny desktop unit with 10m antenna, power supply, cables, CD, and other accessories. It is a low cost addition to our Fury GPSDO line, and contains a really good TCXO, a uBlox GPS receiver, and various power options. I believe this is the lowest-cost real GPSDO in mass production available on the market right now, and being a true GPSDO it has some fairly good phase noise and stability specs. http://www.jackson-labs.com/assets/uploads/main/LC-XO-Plus_PressRelease.pdf bye, Said ___ 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. -- Chris Albertson Redondo Beach, California ___ 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] new GPSDO kit
What will these cost? They will be great for lots and lots of uses but the price determine how that are used. I can buy a 84x48 pixel graphic display for $2.80 shipped. (see ebay 201039107368) and it is very easy to add one of these to a project. I'm kind of stuck on an input device, a 12 key phone type pad would be good or maybe a rotary shaft encoder with push to click shaft. But maybe just four tiny buttons is enough. On Fri, Apr 4, 2014 at 6:11 PM, Mark Sims hol...@hotmail.com wrote: Check out the semi-Arduino + OLED LCD that Sparkfun will be selling soon... it's tiny, fairly cheap, and can run on 3.3 to 18 volts. Looks like it will be very useful for a lot of small projects. Unfortunately, the OLED does not appear to have a touch screen. https://www.sparkfun.com/news/1445 I plan on changing out the LCD display to a $4 Nokia cell phone part that does 84x84 pixel graphics. I'd like to have the GPSDO do its own primitive graphs and setup menus without need to be connected to a computer. ___ 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. -- Chris Albertson Redondo Beach, California ___ 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 GPSDO kit
Hi Brent, I guess thats a trade secret until you buy one :) Bye, Said Sent From iPhone On Apr 4, 2014, at 18:50, KD0GLS kd0...@mninter.net wrote: Said, I looked through the literature on your website, but didn't see any pictures of the inside of the unit. I'm curious to see the board and component compliment. Regards, Brent On Apr 4, 2014, at 20:19, Said Jackson saidj...@aol.com wrote: Paul, Forgot to mention, there is a spec sheet on the website on the LC-XO-Plus product page with additional technical details. Bye, Said Sent from my iPad On Apr 4, 2014, at 17:45, paul swed paulsw...@gmail.com wrote: I mean no disrespect to anyone here. Jacksonlabs makes some very fine components. Brookes comment was spot on. What happens etc. I did run out to the site and take a quick read. The short piece I read did not have a lot of specifics or I simply missed them. It is low power and thats quite a plus, but has to also take into account how it behaves without GPS. Hopefully others will comment. So looking at the price I know that I have seen used Tbolts all over the place up to at least $350 or more. Same for the HPs and they have lots of miles on them. I suspect some comparison to those technologies would be helpful in appreciating whats being offered. Look at the fast turn around Said did. A time-nut says how about a discount and there you go a discount. Regards Paul WB8TSL On Fri, Apr 4, 2014 at 8:20 PM, Chris Albertson albertson.ch...@gmail.comwrote: Wow. Seriously I was just going to post about my $35 GPSDO. I've used some discipline to not say for just a little more I can get... and gone the lowest cost route at each decision point. Just to see what happens. Price does not include GPS receiver, plug-in power cube and case and I'm not shooting for really great spec's. My goal was lowest price possible. The unit is based on the one posted here by Lars Walenius. I replaced his $30 Arudino with a $4 part and added an LCD display. It's not finished yet. I plan on changing out the LCD display to a $4 Nokia cell phone part that does 84x84 pixel graphics. I'd like to have the GPSDO do its own primitive graphs and setup menus without need to be connected to a computer. No intent to compete with a commercial product. I'm not going to sell them. But in time I'll document it. Here is a photo https://www.dropbox.com/s/bsksw9x51ydk6gi/gpsdo.jpg On Fri, Apr 4, 2014 at 3:39 PM, saidj...@aol.com wrote: Hello everyone, sorry for the plug, but we just announced a new $568 complete GPSDO reference kit. This unit is a tiny desktop unit with 10m antenna, power supply, cables, CD, and other accessories. It is a low cost addition to our Fury GPSDO line, and contains a really good TCXO, a uBlox GPS receiver, and various power options. I believe this is the lowest-cost real GPSDO in mass production available on the market right now, and being a true GPSDO it has some fairly good phase noise and stability specs. http://www.jackson-labs.com/assets/uploads/main/LC-XO-Plus_PressRelease.pdf bye, Said ___ 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. -- Chris Albertson Redondo Beach, California ___ 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] M12+T module questions
On 4/4/14 6:51 PM, Chris Albertson wrote: The data connector is a standard 0.05 inch double row of male headers. These are common but not nearly so common as the 0.1 type. I used a 2032 coin cell battery and holder I un-soldered from an dead PC motherboard. Even a coin cell will last its shelf life at least. You will need to level shift the serial data to/from the MT12 if you want to connect it to a PC. I was able to get a sample from Samtec of the connector and a ribbon cable which I could then split out. ___ 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 GPSDO kit
On 4/4/14 5:45 PM, paul swed wrote: I mean no disrespect to anyone here. Jacksonlabs makes some very fine components. Brookes comment was spot on. What happens etc. I did run out to the site and take a quick read. The short piece I read did not have a lot of specifics or I simply missed them. It is low power and thats quite a plus, but has to also take into account how it behaves without GPS. Hopefully others will comment. So looking at the price I know that I have seen used Tbolts all over the place up to at least $350 or more. Same for the HPs and they have lots of miles on them. I suspect some comparison to those technologies would be helpful in appreciating whats being offered. Look at the fast turn around Said did. A time-nut says how about a discount and there you go a discount. Regards Paul WB8TSL and don't forget this is brand new with a warranty vs surplus.. This is a pretty good deal for a turnkey system not requiring assembly. ___ 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.
