Re: [time-nuts] eBay Ublox
Yes, no TRAIM on the uBlox but I haven't seen the TRAIM alarm kicking in on the Motorola/iLotus M12M so I think that for our experiments the uBlox is fine. Even better, have the two: the Motorola/iLotus and the uBlox. On Tue, Jan 3, 2012 at 2:37 AM, k4...@aol.com k4...@aol.com wrote: The problem with the U-Blox receiver is that it does not have TRAIM as does the Motorola UT+ and some others that are made specifically for timing applications. Just be aware of that when trying to decide on which receiver to use. 73's Doug, K4CLE Connected by DROID on Verizon Wireless -Original message- From: Azelio Boriani azelio.bori...@screen.it To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Mon, Jan 2, 2012 09:42:54 GMT+00:00 Subject: Re: [time-nuts] eBay Ublox I have experience with the LEA5-T in timing mode and, and of course, it works as expected. You can set not only how many samples to take but also the variance to achieve before starting the position-hold/timing mode. On Sun, Jan 1, 2012 at 10:44 PM, Bob Camp li...@rtty.us wrote: Hi I haven't used that particular unit. I have played with similar units. That's pretty old stuff, and does not appear to have timing software in it. I suspect you would do *much* better (both performance and price wise) with something newer. Bob On Dec 31, 2011, at 7:41 PM, lstosk...@cox.net lstosk...@cox.net wrote: UBLOX TIM-CJ module TIM-ST GPS engine Jupiter footprint anyone have any experience with this for timing application? N0UU ___ 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] Thunderbolt? (re simple gpsdo.)
Hal wrote: Does anybody know anything about the temperature coefficients of large caps? I'm not interested in the frequency shift of the filter as the temperature but the voltage shift due to a fixed charge as the capacitance changes. The common rule of thumb is thousands of ppm per degree C through their normal operating range (i.e., neglecting low temperatures where they are much worse). Here is what Cornell-Dubilier says about the temperature coefficient of capacitance of aluminum electrolytics : The capacitance varies with temperature. This variation itself is dependent to a small extent on the rated voltage and capacitor size. Capacitance increases less than 5% from 25 ºC to the high temperature limit. For devices rated 40 ºC capacitance declines up to 20% at 40 ºC for low-voltage units and up to 40% for high voltage units. Most of the decline is between 20 ºC and 40 ºC. For devices rated 55 ºC capacitance typically declines less than 10% at 40 ºC and less than 20% at 55 ºC. (see http://www.google.com/url?sa=trct=jq=aluminum+electrolytic+%22temperature+coefficient%22source=webcd=1ved=0CEwQFjAAurl=http%3A%2F%2Fwww.cde.com%2Fcatalogs%2FAEappGUIDE.pdfei=MwMDT728Jcfo0QGggpm4Agusg=AFQjCNEZwwiXQYXxoXbC_on3M5MlOh3ypg at p. 7) 5% is 50k ppm; an 85C cap would thus change 50k ppm over 60 degrees C, or a bit less than 1k ppm per degree C. Based on the timing circuits I've seen implemented with aluminum electrolytics, I'd say CDE is being optimistic here. For integrating in an environment where stability of parts in 10e10 or better is desired, you are likely to find that all of the other imperfections of electrolytic capacitors (leakage, noise, dielectric absorption, etc.) will stop you well short of the goal, never mind the tempco of capacitance. You might get by with wet-slug tantalums. Best regards, Charles ___ 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] seek info 'DSP technology' and other modules
Hope you all had a great entering in 2012. Googling around I could not find any tech info on any of the transiac or DSP technology modules (I could find only many surplus sales...) these are late eighties camac modules... I have no clue if the companies exist or changed names or extinct etc. Any a light on the subject ? (or has catalogs/manuals of such) tks. Luis Cupido. ct1dmk p.s. Also for Kinetic Systems and LeCroy it seems hard too but I could find some stuff, but even so not what I wanted :-( ___ 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] FE 5680a 3pay 36.89 includes shipping. Finally ordered one
I got mine for around $25 in a regular bidding affair. Mine had trouble locking, It only locked a handful of times, and that took forever, but most of the time it just sat there and cooked. The seller replaced it and the new locks up in 2 or 3 minutes. I did not have to ship the old one back. The Lock output signal doesn't seem to have enough drive to turn on an LED. Bob - Original Message - From: Peter Gottlieb n...@verizon.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Monday, January 02, 2012 9:07 PM Subject: Re: [time-nuts] FE 5680a 3pay 36.89 includes shipping. Finally ordered one I grabbed another one for another project. Seller was asking $42.99 and I offered 38.00. He countered at 39.00 and I accepted. Still a great bargain, it would cost me much more than that to replace the failing OCXO it replaces. On 12/28/2011 6:35 PM, Pete Lancashire wrote: My 2nd one a make offer, was $38 anything under $40 and I happy. It has not arrived yet, suppose to have a OCXO -pete On Wed, Dec 28, 2011 at 2:31 PM, paul swedpaulsw...@gmail.com wrote: Well been watching the threads on this RB ref and finally ordered one. Good to see the lower price with shipping. It does not come with the OCXO. No loss for me. Now lets see if it ever shows up? Regards Paul WB8TSL ___ 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. - No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1415 / Virus Database: 2109/4117 - Release Date: 01/01/12 ___ 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] Thunderbolt? (re simple gpsdo.) capacitors
Hi Using electrolytic caps in timing applications is a bit exciting. Their leakage current changes each time you change the voltage on them. It's enough of a change to significantly impact long time constants. In some cases the capacitance changes with voltage as well. Temperature stability of capacitance for most processes is in the 10 to 20% change over 0 to 50C. Leakage at least doubles every 10C. Many ceramic bypass caps have similar TC and change in cap with voltage issues. NPO ceramics or *good* film capacitors are the stuff you make your analog computer out of. (Yes, I'm old enough that you had to check the course description to see if the computer course was analog or digital...) Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Hal Murray Sent: Monday, January 02, 2012 8:15 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Thunderbolt? (re simple gpsdo.) Time constant is just R*C. If you have a 1000uF cap and a 1K resistor you have 1 second. In theory you could build 100s just by using a 100K resistor but I think real world components are not perfect enough. Does anybody know anything about the temperature coefficients of large caps? I found data for ceramic caps, but when I added electrolytic all I got was lifetime stuff rather than capacitance change with temperature. I'm not interested in the frequency shift of the filter as the temperature but the voltage shift due to a fixed charge as the capacitance changes. -- 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. ___ 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] eBay Ublox
Hi I believe that more than just TRAIM goes away when you get the not a T version of the uBlox receivers. You probably should check the jitter on the 1 pps output ... Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Azelio Boriani Sent: Tuesday, January 03, 2012 5:13 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] eBay Ublox Yes, no TRAIM on the uBlox but I haven't seen the TRAIM alarm kicking in on the Motorola/iLotus M12M so I think that for our experiments the uBlox is fine. Even better, have the two: the Motorola/iLotus and the uBlox. On Tue, Jan 3, 2012 at 2:37 AM, k4...@aol.com k4...@aol.com wrote: The problem with the U-Blox receiver is that it does not have TRAIM as does the Motorola UT+ and some others that are made specifically for timing applications. Just be aware of that when trying to decide on which receiver to use. 73's Doug, K4CLE Connected by DROID on Verizon Wireless -Original message- From: Azelio Boriani azelio.bori...@screen.it To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Mon, Jan 2, 2012 09:42:54 GMT+00:00 Subject: Re: [time-nuts] eBay Ublox I have experience with the LEA5-T in timing mode and, and of course, it works as expected. You can set not only how many samples to take but also the variance to achieve before starting the position-hold/timing mode. On Sun, Jan 1, 2012 at 10:44 PM, Bob Camp li...@rtty.us wrote: Hi I haven't used that particular unit. I have played with similar units. That's pretty old stuff, and does not appear to have timing software in it. I suspect you would do *much* better (both performance and price wise) with something newer. Bob On Dec 31, 2011, at 7:41 PM, lstosk...@cox.net lstosk...@cox.net wrote: UBLOX TIM-CJ module TIM-ST GPS engine Jupiter footprint anyone have any experience with this for timing application? N0UU ___ 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. ___ 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] How to read Isotemp OXCO131 part numbers?
Hi More or less: 1) Customer request comes in 2) Custom part number is assigned 3) Prototype ships 4) Customer is tied to custom number This accomplishes a couple of things. It eliminates transcription orders (or at least makes them more obvious). It also can lock out competition and reverse engineering of the end product. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Poul-Henning Kamp Sent: Tuesday, January 03, 2012 2:36 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] How to read Isotemp OXCO131 part numbers? In message cabbxvhuivpuamrehndp0wbtny+q+3msoor_yfckthdk56aj...@mail.gmail.com , Chris Albertson writes: Anyone know how to read Isotemp OXCO131 part numbers? The suffix is a design number, and you cannot infer any specification from it, not even age, since some designs were produced over a long period of time. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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] Thunderbolt? (re simple gpsdo.) capacitors
On Tue, Jan 3, 2012 at 9:14 AM, Bob Camp li...@rtty.us wrote: Hi Using electrolytic caps in timing applications is a bit exciting. Their leakage current changes each time you change the voltage on them. It's enough of a change to significantly impact long time constants. In some cases the capacitance changes with voltage as well.. In general you are right. But in this case the electrolytic cap is inside a closed loop so as the temperature changes and the voltage in the cap changes, the loop will correct it, as long the temperature changes slowly compared to how frequently we measure the phase of the PPS signal. You could always place the entire system inside box and control it to a constant temperature. -- 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] Thunderbolt? (re simple gpsdo.) capacitors
Hi No argument there, but this thread has wandered a bit. If you are depending on the capacitor to provide a specific time constant, then you will have issues. If the control loop is not impacted by the changes, then they will track out. Often it's not quite an either / or, but a some of this and some of that. In any case the noise created by the leakage current in an electrolytic will be an issue outside the loop bandwidth and only will be reduced by the available gain... Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Chris Albertson Sent: Tuesday, January 03, 2012 12:35 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Thunderbolt? (re simple gpsdo.) capacitors On Tue, Jan 3, 2012 at 9:14 AM, Bob Camp li...@rtty.us wrote: Hi Using electrolytic caps in timing applications is a bit exciting. Their leakage current changes each time you change the voltage on them. It's enough of a change to significantly impact long time constants. In some cases the capacitance changes with voltage as well.. In general you are right. But in this case the electrolytic cap is inside a closed loop so as the temperature changes and the voltage in the cap changes, the loop will correct it, as long the temperature changes slowly compared to how frequently we measure the phase of the PPS signal. You could always place the entire system inside box and control it to a constant temperature. -- 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.
Re: [time-nuts] FE 5680a 3pay 36.89 includes shipping. Finally ordered one
If you don't want the bad one I would be interested so I could disassemble and diagram it out. I don't want to do that to a good one. On 01/03/12, Robert Benwardrbenw...@verizon.net wrote: I got mine for around $25 in a regular bidding affair. Mine had trouble locking, It only locked a handful of times, and that took forever, but most of the time it just sat there and cooked. The seller replaced it and the new locks up in 2 or 3 minutes. I did not have to ship the old one back. The Lock output signal doesn't seem to have enough drive to turn on an LED. Bob - Original Message - From: Peter Gottlieb [1]n...@verizon.net To: Discussion of precise time and frequency measurement [2]time-nuts@febo.com Sent: Monday, January 02, 2012 9:07 PM Subject: Re: [time-nuts] FE 5680a 3pay 36.89 includes shipping. Finally ordered one I grabbed another one for another project. Seller was asking $42.99 and I offered 38.00. He countered at 39.00 and I accepted. Still a great bargain, it would cost me much more than that to replace the failing OCXO it replaces. On 12/28/2011 6:35 PM, Pete Lancashire wrote: My 2nd one a make offer, was $38 anything under $40 and I happy. It has not arrived yet, suppose to have a OCXO -pete On Wed, Dec 28, 2011 at 2:31 PM, paul swed[3]paulsw...@gmail.com wrote: Well been watching the threads on this RB ref and finally ordered one. Good to see the lower price with shipping. It does not come with the OCXO. No loss for me. Now lets see if it ever shows up? Regards Paul WB8TSL ___ time-nuts mailing list -- [4]time-nuts@febo.com To unsubscribe, go to [5]https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- [6]time-nuts@febo.com To unsubscribe, go to [7]https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. - No virus found in this message. Checked by AVG - [8]www.avg.com Version: 10.0.1415 / Virus Database: 2109/4117 - Release Date: 01/01/12 ___ time-nuts mailing list -- [9]time-nuts@febo.com To unsubscribe, go to [10]https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. References 1. mailto:n...@verizon.net 2. mailto:time-nuts@febo.com 3. mailto:paulsw...@gmail.com 4. mailto:time-nuts@febo.com 5. https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts 6. mailto:time-nuts@febo.com 7. https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts 8. http://www.avg.com/ 9. mailto:time-nuts@febo.com 10. https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ 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] eBay Ublox
Oh no, I was speaking always of timing version GPSes. For non timing version GPSes you loose the position-hold timing mode too. uBlox has T-RAIM in the LEA6-T version. In the block diagram of uBlox GPSes they show the option XTAL/TCXO for their receivers. Although not stated, I believe that the TCXO option is reserved for the timing version hardware. On Tue, Jan 3, 2012 at 6:16 PM, Bob Camp li...@rtty.us wrote: Hi I believe that more than just TRAIM goes away when you get the not a T version of the uBlox receivers. You probably should check the jitter on the 1 pps output ... Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Azelio Boriani Sent: Tuesday, January 03, 2012 5:13 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] eBay Ublox Yes, no TRAIM on the uBlox but I haven't seen the TRAIM alarm kicking in on the Motorola/iLotus M12M so I think that for our experiments the uBlox is fine. Even better, have the two: the Motorola/iLotus and the uBlox. On Tue, Jan 3, 2012 at 2:37 AM, k4...@aol.com k4...@aol.com wrote: The problem with the U-Blox receiver is that it does not have TRAIM as does the Motorola UT+ and some others that are made specifically for timing applications. Just be aware of that when trying to decide on which receiver to use. 73's Doug, K4CLE Connected by DROID on Verizon Wireless -Original message- From: Azelio Boriani azelio.bori...@screen.it To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Mon, Jan 2, 2012 09:42:54 GMT+00:00 Subject: Re: [time-nuts] eBay Ublox I have experience with the LEA5-T in timing mode and, and of course, it works as expected. You can set not only how many samples to take but also the variance to achieve before starting the position-hold/timing mode. On Sun, Jan 1, 2012 at 10:44 PM, Bob Camp li...@rtty.us wrote: Hi I haven't used that particular unit. I have played with similar units. That's pretty old stuff, and does not appear to have timing software in it. I suspect you would do *much* better (both performance and price wise) with something newer. Bob On Dec 31, 2011, at 7:41 PM, lstosk...@cox.net lstosk...@cox.net wrote: UBLOX TIM-CJ module TIM-ST GPS engine Jupiter footprint anyone have any experience with this for timing application? N0UU ___ 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. ___ 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] FE 5680a 3pay 36.89 includes shipping. Finally ordered one
On 1/3/2012 8:20 AM, Robert Benward wrote: I got mine for around $25 in a regular bidding affair. Mine had trouble locking, It only locked a handful of times, and that took forever, but most of the time it just sat there and cooked. The seller replaced it and the new locks up in 2 or 3 minutes. I did not have to ship the old one back. The Lock output signal doesn't seem to have enough drive to turn on an LED. One of the three FE-5680A units I got behaved exactly that way. Turns out some part of a VCXO circuit had drifted over time (I assume) so the free-running frequency never quite reached up to 10.000 MHz enabling lock to the signal from the physics package. Assuming you do have a 10 MHz output signal, put a counter on it while it is warming up and look at the frequency. After I fixed it, the frequency vs time from startup plot looked like this: https://picasaweb.google.com/lh/photo/7E22rkh_YivyesrnTog6atMTjNZETYmyPJy0liipFm0?feat=directlink The fix was to take off case top and bottom and tweak the trimmer cap marked C217 slightly, it is near Y200 (crystal with round PTC thermistor attached). Here's a photo of that part of the board: https://picasaweb.google.com/109928236040342205185/FE5680A?authkey=djqVhWs9LkM#5680683008490223330 Of course there may be some completely different problem with your unit, but it's something to try, if you want to open it up and play with it. -John Beale ___ 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] Thunderbolt? (re simple gpsdo.) capacitors
this thread has wandered a bit. The thread was originally for Simple... Bottom line is that electrolytic caps can be made to work fine for a SIMPLE analog controller built for home NUT use, Not recommended for space or critical life support applications, or any production thing. Besides putting the crappie RC inside a closed loop the other thing that seems several are missing is to limit the correction range. If one sets up the simple loop to give say a 100 to 1 improvement, then all the other concerns become non-issues. The noise created by the leakage current in an electrolytic will be an issue outside the loop bandwidth and only will be reduced by the available gain... Loop Gain is not a problem when making a frequency lock loop, even with a P only controller, using any kind of phase detector because the gain is infinite. The leakage current noise I measured was way below insignificant when things are properly scaled. Such as when you scale it so you only care about a 1% of 5 volt change and not uv. If you're depending on a specific time constant for a SIMPLE controller using electrolytic caps then the problem is the design and not the caps. If you're want to make a 1e-10 to one correction with a simple controller the problem is not the cap but the configuration and the expectations. But making a 1e-13 correction to a 1e-9 Rb is no problem (1000 to one improvement) Hal Murray Posted: I'm not interested in the frequency shift of the filter as the temperature but the voltage shift due to a fixed charge as the capacitance changes. Interesting question, so I tried it. No effect on the One I tested. I charged a cheapie 1000uf, 50V cap to 5 volts then changed it's temperature which did changed it's capacitance and leakage, but had no effect on it's charge voltage. I guess the charge is not Fixed, so not the same thing as changing the value by paralleling the cap. ws ** [time-nuts] Thunderbolt? (re simple gpsdo.) capacitors Bob Camp lists at rtty.us Hi No argument there, but this thread has wandered a bit. If you are depending on the capacitor to provide a specific time constant, then you will have issues. If the control loop is not impacted by the changes, then they will track out. Often it's not quite an either / or, but a some of this and some of that. In any case the noise created by the leakage current in an electrolytic will be an issue outside the loop bandwidth and only will be reduced by the available gain... Bob *** On Behalf Of Chris Albertson Hi Using electrolytic caps in timing applications is a bit exciting. Their leakage current changes each time you change the voltage on them. It's enough of a change to significantly impact long time constants. In some cases the capacitance changes with voltage as well.. In general you are right. But in this case the electrolytic cap is inside a closed loop so as the temperature changes and the voltage in the cap changes, the loop will correct it, as long the temperature changes slowly compared to how frequently we measure the phase of the PPS signal. You could always place the entire system inside box and control it to a constant temperature. 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] Thunderbolt? (re simple gpsdo.) capacitors
In message 80B26DC756AA45DD84E4EB9E14B58998@Warcon28Gz, WarrenS writes: The leakage current noise I measured was way below insignificant when things are properly scaled. Really stupid question: Couldn't the double condensor from voltage references trick be used to eliminate the leakage entirely ? [Some op-amp] -++-- || | - | - | | +--||+ | - - | | GND -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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] eBay Ublox
Yes, and the new uBlox timing GPS have a software jamming sensor and indicator which the Motorola/iLotus products do not have, and they are much easier to get to work at a users' site than the Motorola parts, and much more robust against jamming than the Motorola timing GPS. We have done extensive tests here on our products that use the LEA-6T to prove that. There are significant advantages in performance and easy-of-use to the ublox parts compared to all other alternatives in the market today. Still the Motorola designed parts have the best timing performance with a margin when properly operated, so they still have significant applications for many years to come - one reason we offer the uBlox parts in some of our products and the Motorola parts in others (i.e. Fury GPSDO). BTW: I applaud the use of the eBay name in this thread. I think many members here are doing a dis-sevice on this list by naming it ePay, 3Pay or whatever. They don't seem to remember what it was like getting equipment before Ebay was around, and while I curse the Ebay fees and policies, Ebay offers a great service, and we should give them the respect they deserve in my opinion. If you don't like Ebay, then don't use them, use Craigslist or used-line etc. bye, Said In a message dated 1/3/2012 10:25:26 Pacific Standard Time, azelio.bori...@screen.it writes: Oh no, I was speaking always of timing version GPSes. For non timing version GPSes you loose the position-hold timing mode too. uBlox has T-RAIM in the LEA6-T version. In the block diagram of uBlox GPSes they show the option XTAL/TCXO for their receivers. Although not stated, I believe that the TCXO option is reserved for the timing version hardware. ___ 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] FE-5680A clock shaping (sine - square wave)
On Tue, 03 Jan 2012 07:01:13 +0100, ehydra ehy...@arcor.de wrote: David schrieb: I could analyze it on SPICE but I suspect the real world construction parasitics will be what limits the performance. I just sketched it out in my notebook but I will see if I can post it somewhere. Is there a quick and dirty online schematic capture site? Scan it. I will make a LTspice file. It is not that complicated being a differential amplifier driving complementary pair of emitter followers, a pair of voltage clamps, and then a pair of complementary current mirrors configured as transconductance amplifiers. I want to SEE it including all circuit parameters. Thank you. I am entering it into LT Spice for practice. I will post the results and files here when done. I need to rethink the level shift configuration. When you say symmetry limiting do you mean to prevent second harmonic distortion like for driving a mixer? I was thinking of this more for driving a single ended transmission line cleanly while maximizing the edge rates and minimizing jitter. Duty cycle correction could be added pretty easily. Hm. I think second harmonic distortion looks very much like intentional symmetric waveform in the first instance. The fun begins if we decide to look for equal time distance or equal power for both phases. Interesting. The circuit you linked is going to have a little problem since both the 2N5769 and the 2N5770 are NPN and the circuit requires a pair of PNPs. Other than that it looks perfect for driving a high level mixer. As far as I know driving a mixer was the circuit intention. I SPICEd it with BFR93 types. The circuit has a high reflection coefficient, unfortunately. Maybe this is unavoidable and we need a diplexer. The output is low impedance, unmatched, and I suspect not quite symmetrical so I would expect this. Does it matter though if the mixer is close by? Yes, looks like an typo for having 4 NPNs there. I will clarify this with Chris Trask. Thanks. Unfortunately, RF PNP transistors tend to be rare or expensive so when I saw that schematic my first thought was, Hmm. I wonder if that is the RF PNP I have been looking for. I did not know the 2N5770 had a PNP complement. Wait a sec . . . I have been considering the PNP BFG21 and NPN BFG97 made by NXP. They are SOT-223 so should be easier to prototype with than a smaller package. The On Semiconductor TO-92 NPN MPSH10 and PNP MPSH81 would be good also but the later is being discontinued. ___ 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] FE 5680a 3pay 36.89 includes shipping. Finally ordered one
Peter, Sure, If I can have a copy of what you produce. Send me your address. I assume you are in the US? If you look on Ebay, this is one of those that was mounted on a PCB with an aux 68MHz osc and DB9 connector. Bob - Original Message - From: Peter Gottlieb n...@verizon.net To: time-nuts@febo.com Sent: Tuesday, January 03, 2012 1:18 PM Subject: Re: [time-nuts] FE 5680a 3pay 36.89 includes shipping. Finally ordered one If you don't want the bad one I would be interested so I could disassemble and diagram it out. I don't want to do that to a good one. On 01/03/12, Robert Benwardrbenw...@verizon.net wrote: I got mine for around $25 in a regular bidding affair. Mine had trouble locking, It only locked a handful of times, and that took forever, but most of the time it just sat there and cooked. The seller replaced it and the new locks up in 2 or 3 minutes. I did not have to ship the old one back. The Lock output signal doesn't seem to have enough drive to turn on an LED. Bob - Original Message - From: Peter Gottlieb [1]n...@verizon.net To: Discussion of precise time and frequency measurement [2]time-nuts@febo.com Sent: Monday, January 02, 2012 9:07 PM Subject: Re: [time-nuts] FE 5680a 3pay 36.89 includes shipping. Finally ordered one I grabbed another one for another project. Seller was asking $42.99 and I offered 38.00. He countered at 39.00 and I accepted. Still a great bargain, it would cost me much more than that to replace the failing OCXO it replaces. On 12/28/2011 6:35 PM, Pete Lancashire wrote: My 2nd one a make offer, was $38 anything under $40 and I happy. It has not arrived yet, suppose to have a OCXO -pete On Wed, Dec 28, 2011 at 2:31 PM, paul swed[3]paulsw...@gmail.com wrote: Well been watching the threads on this RB ref and finally ordered one. Good to see the lower price with shipping. It does not come with the OCXO. No loss for me. Now lets see if it ever shows up? Regards Paul WB8TSL ___ time-nuts mailing list -- [4]time-nuts@febo.com To unsubscribe, go to [5]https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- [6]time-nuts@febo.com To unsubscribe, go to [7]https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. - No virus found in this message. Checked by AVG - [8]www.avg.com Version: 10.0.1415 / Virus Database: 2109/4117 - Release Date: 01/01/12 ___ time-nuts mailing list -- [9]time-nuts@febo.com To unsubscribe, go to [10]https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. References 1. mailto:n...@verizon.net 2. mailto:time-nuts@febo.com 3. mailto:paulsw...@gmail.com 4. mailto:time-nuts@febo.com 5. https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts 6. mailto:time-nuts@febo.com 7. https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts 8. http://www.avg.com/ 9. mailto:time-nuts@febo.com 10. https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ 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] How to read Isotemp OXCO131 part numbers?
In a message dated 02/01/2012 23:53:41 GMT Standard Time, azelio.bori...@screen.it writes: Yes, seems difficult to find the differences but I've found at least the 131-2: http://w9fz.com/ham/OCXO131-2Spec.pdf -- Some more here. _http://www.isotemp.com/wp-content/uploads/2011/07/_ (http://www.isotemp.com/wp-content/uploads/2011/07/) and here. _http://www.isotemp.com/wp-content/uploads/2011/10/_ (http://www.isotemp.com/wp-content/uploads/2011/10/) Plus some other info on the associated pages to these links. Regards Nigel GM8PZR ___ 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] How to read Isotemp OXCO131 part numbers?
Yes, found others but, for example, we use the 131-40 and have the datasheet: can't find it from those URLs. You can find 131-42 131-45 and 131-1000, 1001, 1002 and so on. Our 131-40 was not made for us but decided to use it with the permission of the original customer to increase the order volume. On Tue, Jan 3, 2012 at 11:02 PM, gandal...@aol.com wrote: In a message dated 02/01/2012 23:53:41 GMT Standard Time, azelio.bori...@screen.it writes: Yes, seems difficult to find the differences but I've found at least the 131-2: http://w9fz.com/ham/OCXO131-2Spec.pdf -- Some more here. _http://www.isotemp.com/wp-content/uploads/2011/07/_ (http://www.isotemp.com/wp-content/uploads/2011/07/) and here. _http://www.isotemp.com/wp-content/uploads/2011/10/_ (http://www.isotemp.com/wp-content/uploads/2011/10/) Plus some other info on the associated pages to these links. Regards Nigel GM8PZR ___ 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] crunching numbers from XOR phase detector
Previously I have been comparing 10 MHz frequencies using TvB's picPET device plus a picDIV divider to get a 1 PPS signal, but I wanted more resolution for comparing relative drift of two Rb references. I got square wave outputs from my references (see my previous posts) and I made a simple XOR phase detector from a single XOR gate (74LVC1G86) : https://picasaweb.google.com/lh/photo/ofFwP8Eo1qFAzNObq69iCtMTjNZETYmyPJy0liipFm0 I have read about how nonlinear the XOR PD becomes at the endpoints (0 and 180 phase shift) although this one seems to work pretty well, and the output looks reasonably triangular: https://picasaweb.google.com/lh/photo/swKVhhP7NerRvMKdnW8rjtMTjNZETYmyPJy0liipFm0 There is some nonlinearity but it seems consistent from cycle to cycle. I might be able to reduce the bumps with better circuit layout, shorter wires, terminated lines etc. But just for playing around with my initial data, I think I can model the shape of the response and get a more accurate reading of instantaneous phase angle vs time. I could write some code for this, but I suspect this wheel has been invented before... is there any reference I should consult? I think something similar is done inside the PIC-TIC to calibrate its response? ___ 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] FE-5680A dumb question...
My E-bay FE-5680A finally arrived. (4weeks later) Of the pins on the DB-9 connector, which one is the RF output? The manual only talks about an SMA output. I know this has been talked about before, but I cannot find the thread. Thanks in advance sorry for bandwidth, -Brian, WA1ZMS ___ 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] crunching numbers from XOR phase detector
There is some nonlinearity but it seems consistent from cycle to cycle. I might be able to reduce the bumps with better circuit layout, shorter wires, terminated lines etc. But just for playing around with my initial data, I think I can model the shape of the response and get a more accurate reading of instantaneous phase angle vs time. I could write some code for this, but I suspect this wheel has been invented before... is there any reference I should consult? I think something similar is done inside the PIC-TIC to calibrate its response? John, Very nice plot. Thanks for sharing that. The next step is simply to differentiate and then re-plot the data (you know that's just one line of code: x[i+1] - x[i]). You should see two lines, +slope and -slope. Then take the absolute value. You should now see one line and the auto-scaled plot will show in much greater detail the variations of Rb performance and/or XOR non-linearity. Make these two plots and then I'll walk you through the next step. /tvb ___ 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] crunching numbers from XOR phase detector
Having access to two Rb sources and looking at phase shift and jitter is something I find interesting. Has anyone fed two Rb sourced 10mhz signals in to a high-z an op-amp and looked at the output on a SA ? Should probably have at least 100mhz bw on the SA in order to see the events. A few tests to run with this experiment are 1) From cold: phase spectra to lock 2) From hot(power cycle) phase spectral to lock -- both power down/up at the same time. then vice versa 3) phase spectra relative to heat( forced air heat sinking, thermal blanketing ,etc) Obviously this test is geared for short term phase events, where as you are looking for long term. I find both equally interesting. When i get some extra time and hardware, I'm going to end up performing this very test. Steve ___ 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] Navsync CW-12 GPS Board - I don't believe it!!
In the past I've mentioned the Navsync CW-12 GPS board. Oncore M12 drop-in replacement, 1 PPS ( measured Standard Deviation 5 ns., range ~ 30 ns. from min to max for 1000 measurements), and a 10 MHz output that's 'steered by the GPS receiver'. The recent discussions about a cheap, simple GPSDO motivated me to try an idea I've had in the back of my mind for a while. I wanted to use a double-balanced mixer as a phase detector to phase-lock a 10 MHz OCXO to the 10 MHz output of the CW-12 at 10 MHz - no dividers. I threw together a proof-of-concept circuit and it worked as expected. But then I compared the OCXO output to the 10 MHz output of both a Z3801A and a Tbolt and discovered that the CW-12's 10 MHz output is about 1.5e-11 (i.e. 1.5e-4 Hz) low in frequency. I emailed Navsync and they replied: The CW12 Motorola Binary and NMEA versions both do not phase align the frequency output so the long term drift that Ed is seeing is expected. Incredible. It's 'steered by the GPS receiver' - that's a direct quote from the data sheet and the user manual - but it's not quite on frequency and that's fine with them. I checked the 1 PPS and it looks okay. Compared to the 1 PPS from the Tbolt, over 20K seconds it wanders back and forth over a range of about 90 ns. Lady Heather reported about 50 ns. of wander for the Tbolt over the same period. I know that some of you have CW-12s and I just wanted to let you know about this. I'd also be interested if you can run similar tests and confirm my results. Ed P.S. I have to laugh at myself. Here I am whining about something that's off by 15 parts per trillion. I'm a time-nut all right! :-) ___ 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] eBay Ublox
On 12/31/2011 07:41 PM, lstosk...@cox.net wrote: UBLOX TIM-CJ module TIM-ST GPS engine Jupiter footprint After finding these, and buying a couple, I found item 220915477952 U-Blox RCB-LJ receiver boards, cheaper ($9) and (I think) newer. If I have the spec sheets figured out, the TIM-CJ module uses a SiRF II module and the RCB-LJ uses ANTARIS. Anybody know the difference? anyone have any experience with this for timing application? I used one of these boards, the RCB-LJ if I remember correctly, in about 2004. It provided both location (fixed) and time, but we did not need really high precision timing. 10s of microseconds was good enough. Our main selection criteria was low power. gc N0UU ___ 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] FE 5680a 3pay 36.89 includes shipping. Finally ordered one
Hi John, I did you what you suggested and it locks now. I tweaked so that the output is only 10-20Hz above 10MHz. It seems to lock on the way down from the peak (high) frequency, it doesn't seem to lock on the way up. It seems to agree with one of your plots, but no the other. You don't say what he difference is between the plots. It is sensitive to vibration, it seem to unlock easily when bumped. Do you know what the other trimmer is for? Bob - Original Message - From: John Beale be...@bealecorner.com To: time-nuts@febo.com Sent: Tuesday, January 03, 2012 1:29 PM Subject: Re: [time-nuts] FE 5680a 3pay 36.89 includes shipping. Finally ordered one On 1/3/2012 8:20 AM, Robert Benward wrote: I got mine for around $25 in a regular bidding affair. Mine had trouble locking, It only locked a handful of times, and that took forever, but most of the time it just sat there and cooked. The seller replaced it and the new locks up in 2 or 3 minutes. I did not have to ship the old one back. The Lock output signal doesn't seem to have enough drive to turn on an LED. One of the three FE-5680A units I got behaved exactly that way. Turns out some part of a VCXO circuit had drifted over time (I assume) so the free-running frequency never quite reached up to 10.000 MHz enabling lock to the signal from the physics package. Assuming you do have a 10 MHz output signal, put a counter on it while it is warming up and look at the frequency. After I fixed it, the frequency vs time from startup plot looked like this: https://picasaweb.google.com/lh/photo/7E22rkh_YivyesrnTog6atMTjNZETYmyPJy0liipFm0?feat=directlink The fix was to take off case top and bottom and tweak the trimmer cap marked C217 slightly, it is near Y200 (crystal with round PTC thermistor attached). Here's a photo of that part of the board: https://picasaweb.google.com/109928236040342205185/FE5680A?authkey=djqVhWs9LkM#5680683008490223330 Of course there may be some completely different problem with your unit, but it's something to try, if you want to open it up and play with it. -John Beale ___ 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] Navsync CW-12 GPS Board - I don't believe it!!
Wait...they said it is good enough for government work? This is an interesting discovery, but I wonder if this is intentional for some not so obvious reason. ___ 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.
