[time-nuts] Literature on low noise and HF electronics
Moin, The recent discussions have made it again clear to me, that i lack a lot of knowledge in electronics. Especially when it comes to the black arts: analog stuff, HF, getting the most ouf of a transistor, or doing it really really low noise. Could someone recomend anything to read that would get me more insights and knowledge on these topics? May it be books, papers or search terms for google. Thanks in advance Attila Kinali -- Why does it take years to find the answers to the questions one should have asked long ago? ___ 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] Literature on low noise and HF electronics
Attila wrote: The recent discussions have made it again clear to me, that i lack a lot of knowledge in electronics. Especially when it comes to the black arts: analog stuff, HF, getting the most ouf of a transistor, or doing it really really low noise. Could someone recomend anything to read that would get me more insights and knowledge on these topics? There are a few good textbooks (read, lots of math) on HF and low noise design if you have the math and physics foundation. The way you presented your request, it sounds as if you may want something more foundational. If so, I would highly recommend The Art of Electronics by Horowitz and Hill and Experimental Methods in RF Design by Hayward, Campbell, and Larkin. I have used them both as textbooks for designers at a variety of levels, and they are exceptional for the authors' ability to convey an intuitive understanding of the material. They both have sufficient math that someone familiar with the field will not feel slighted, but they don't rely solely on the math to get their points across as most textbooks do. They are remarkable for being useful to designers and aspiring designers at widely varying levels of competence. I do not know of a similar book about low-noise design, but it is covered quite well in both of the books above. 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.
Re: [time-nuts] Literature on low noise and HF electronics
On Sat, 11 Feb 2012 04:09:44 -0500 Charles P. Steinmetz charles_steinm...@lavabit.com wrote: Attila wrote: The recent discussions have made it again clear to me, that i lack a lot of knowledge in electronics. Especially when it comes to the black arts: analog stuff, HF, getting the most ouf of a transistor, or doing it really really low noise. Could someone recomend anything to read that would get me more insights and knowledge on these topics? There are a few good textbooks (read, lots of math) on HF and low noise design if you have the math and physics foundation. Having a master in EE i think i can handle quite a bit of math. ;-) Unfortunately, having a degree doesn't mean you know anything. And my experience is that for lots of things i need at work on a daily basis, there was no course, not even something mentioning that this might be something you should know. And as it is, university courses focus more and more on communication technologies. Ie, on either how you design a transistor on a chip to do GHz transmissions or how you would encode your signal to get trough a noisy channel. No word on how you get an actuall device build or how you would implement the nice theoretical signal shape you just calculated... The most practical course i had, was on digital chip design, where we learned various practices and a great deal of VHDL. Most of the rest was so theoretical that i still do not know how to apply them to real world problems. And now i'm trying to fill that gab. The way you presented your request, it sounds as if you may want something more foundational. That's one part. I know i lack a lot of basic things, that are part of the craft. But i also want to learn the special stuff. Eg one of the books i recently bought was on what forms of noise are present in low noise oscillators and how to characterise them. Very specialized book, but i learned a great deal while reading it. If so, I would highly recommend The Art of Electronics by Horowitz and Hill This is already on my to buy list :-) and Experimental Methods in RF Design by Hayward, Campbell, and Larkin. Thanks, i'll get this one too. Thanks a lot Attila Kinali -- Why does it take years to find the answers to the questions one should have asked long ago? ___ 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] Using digital broadcast TV for timing?
On 02/10/2012 06:56 PM, Bob Camp wrote: Hi I suspect that if you went into the GPS jamming business that the mob of lawyers would be even more scary than the stuff being dropped on your antennas... Not even the US military could be that evil!!! If you attempts that total jamming approach then you are probably a state. There are a few states which actually do such jammings to telecom sats. I think they would not care what the lawyers says. I also think the US air force would care about their strategic assets being under continuous attack. Cheers, Magnus Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Magnus Danielson Sent: Thursday, February 09, 2012 4:17 PM To: time-nuts@febo.com Subject: Re: [time-nuts] Using digital broadcast TV for timing? On 02/09/2012 07:21 PM, Chris Albertson wrote: On Wed, Feb 8, 2012 at 11:02 PM, Hal Murrayhmur...@megapathdsl.net wrote: Other than LightSquared, an event that made GPS go away would most likely eliminate most interest in ultra accuracy time keeping. By went away, I meant locally, as be being jammed or spoofed. Possibly a car drives into a tunnel and then from the car's point of view GPS goes away. From a military point of view all it takes to knock out GPS is to suicide truck-bomb both ground control stations or simply jam the GPS uplinks so the stations are unable to send commands. But The question was more theoretical then practical. Let's assume that the physical safety of the ground control center is there, and just have a look at the jamming of up-links. Jamming the up-links would be a bit of a difficult task, since there is not one but several up-links, also you would need to high-energy jam all the birds as you would not know when they would get their commands. Add their capability of cross-link communication and ability to uphold a decent situation in autonav for ground station outage of up to 180 days. Oh, both uplink and cross-link is encrypted and fairly jam-resistant. Cross-link has nulls towards earth and only a half-decent gain in certain angles. All that comes out of public sources. It would take a bit of resources to do a global GPS outage, and to maintain it you would expose yourself over a long time such that you would be found and well, let's assume that your antennas will not take kindly to the things being dropped at it. Regional outages is much easier. Cheers, Magnus ___ 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] Literature on low noise and HF electronics
Another suggestion if you are interested in analogic design is Sergio Franco, Design with Operational Amplifiers and Analog Integrated Circuits, McGraw Hill, 1988 (and other newer editions). Common on ebay and amazon. Chapter 14 (noise in operational amplifiers) has been very useful to me. Marco IK1ODO ___ 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] Literature on low noise and HF electronics
Information Transmission, Modulation and Noise by Mischa Schwartz. ___ 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] Literature on low noise and HF electronics
Optimum noise immunity , Originally a Russian book but translated by R.A. Silverman. (somewhat dated, but very good coverage in theory, heavy math,statistics and scientific method) Due to the nature of the above book if you are not familiar with the scientific of experimentation on a practicing level, I must also recommend: Experimentation: An introduction to measurement theory and experiment design, By D.C. Baird. This book also somewhat dated, but i find them much more useful than any of modern texts. ___ 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] GPS lock of the FE5680. Current experiment and question
Hi Another way to build an analog phase detector... Next layer on the onion is how to get the sawtooth correction out of the GPS and into your loop. Bob On Feb 11, 2012, at 12:05 AM, Chris Albertson albertson.ch...@gmail.com wrote: All these different suggestions build down to one thing, the precision with which you measure the phase when you sample it each second. The single flip flop will tell you which half cycle. a simple two bit counter made with two '74 FFs tells you which half cycle and with direction. The best maybe is if you let the PPS set a FF and the 10MHz reset it. The FF's output gates a constant current to a capacitor and charges it to some voltage. Then you measure that with a 10-bit ADC. This measures the phase to maybe 1%, gives you direction and is pretty cheap to build Let's see if I have the numbers right? If you check a 10MHz signal once per second with just the FF then you have 1E-7. You would need 1000 seconds for 1E-10. But if you measure phase to 1/10th of a cycle you get to 1E-10 ten faster. Right? 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] Picotest U6200A Timelab
Gentlemen, a few weeks ago a link to a new counter named U6200A was to be found here in the group. I considered the technical properties of this counter (which is sold under the brands Array or Picotest) that interesting at its price that i ordered one immediately. I did not buy it directly from China but instead from a German importer called OSCOMP. They were able to deliver me the counter with a built in GPIB-interface. I had not been able to allocate a seller in China with this option. I am currently testing the counter and as far everything looks pretty good. You can get an impression of the counter's capabilities by the direct comparison to the industry standard here: http://www.stantronic.de/b/Comparison-U6200A.pdf At its price and the 40 ps single shot resolution it may be a good idea to buy such a counter new for time nuts purposes instead of hunting for used 5370s and SR620s. Since the manual claims that the counter features a HP53132 compatible SCPI command languge I tried to run John Miles's Timelab with the counter which failed in the beginning. Due to John's immediate reaction on my inquiry concerning the U6200a Timelab now has its own hardware entry for te U6200A in the Acquire menu and my tests show that Timelab runs like charm with the U6200A. Note that Timelab checks the device id with a *IDN? and the current version recognizes the Picotest brand answer to this. This may be different with the Array brand id. Best regards Ulrich Bangert www.ulrich-bangert.de Ortholzer Weg 1 27243 Gross Ippener Germany ___ 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] Picotest U6200A Timelab
Hi If I hit the Acquire / U6200A entry in the Timelab menu will it buy one for me? How noisy is it? Put another way, it has 40 ps resolution, how close can you get to that in terms of accuracy? Looks like a cool toy, thanks for sharing. Bob On Feb 11, 2012, at 7:52 AM, Ulrich Bangert df...@ulrich-bangert.de wrote: Gentlemen, a few weeks ago a link to a new counter named U6200A was to be found here in the group. I considered the technical properties of this counter (which is sold under the brands Array or Picotest) that interesting at its price that i ordered one immediately. I did not buy it directly from China but instead from a German importer called OSCOMP. They were able to deliver me the counter with a built in GPIB-interface. I had not been able to allocate a seller in China with this option. I am currently testing the counter and as far everything looks pretty good. You can get an impression of the counter's capabilities by the direct comparison to the industry standard here: http://www.stantronic.de/b/Comparison-U6200A.pdf At its price and the 40 ps single shot resolution it may be a good idea to buy such a counter new for time nuts purposes instead of hunting for used 5370s and SR620s. Since the manual claims that the counter features a HP53132 compatible SCPI command languge I tried to run John Miles's Timelab with the counter which failed in the beginning. Due to John's immediate reaction on my inquiry concerning the U6200a Timelab now has its own hardware entry for te U6200A in the Acquire menu and my tests show that Timelab runs like charm with the U6200A. Note that Timelab checks the device id with a *IDN? and the current version recognizes the Picotest brand answer to this. This may be different with the Array brand id. Best regards Ulrich Bangert www.ulrich-bangert.de Ortholzer Weg 1 27243 Gross Ippener Germany ___ 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] Picotest U6200A Timelab
Ulrich Bangert- a few weeks ago a link to a new counter named U6200A was to be found here in the group. I considered the technical properties of this counter (which is sold under the brands Array or Picotest) that interesting at its price that i ordered one immediately. + Actually the counter was very briefly discussed 4 months ago in VIGO time interval devices 10-31-2011 where I posted: Has anyone looked into the Picotest (also sold as Array) U6200A TIC? Looks like DC-6Ghz with 12 digits/sec and 40ps resolution. Check the specs at: http://www.picotest.com.tw/product02.html One seller on the popular auction site has them for $1270 (with shipping). Interestingly the $1200 price was much lower than everyone else was asking by about $1000. I didn't buy one but in December someone did buy one and posted this feedback: Bought item a month ago. now asking me to pay $900 more. The seller apparently didn't do their currency conversion correctly. I don't know if the buyer had to pay the difference or not but I'd guess not. -Arthur ___ 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] Literature on low noise and HF electronics
On 2/11/12 12:43 AM, Attila Kinali wrote: Moin, The recent discussions have made it again clear to me, that i lack a lot of knowledge in electronics. Especially when it comes to the black arts: analog stuff, HF, getting the most ouf of a transistor, or doing it really really low noise. Could someone recomend anything to read that would get me more insights and knowledge on these topics? May it be books, papers or search terms for google. Thanks in advance Attila Kinali RF circuit design, by Bowick http://www.amazon.com/Circuit-Design-Second-Christopher-Bowick/dp/0750685182/ref=pd_sim_b_1 It's kind of a handbook of design with a fair amount of theory. I don't know that it gets into esoterica of ultimate low noise. ___ 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] GPS lock of the FE5680. Current experiment and question
This is the simplest part if a microprocessor can be used: by the serial port you get the sawtooth correction in nS to be applied to the sampled data. The sampled data must be converted to nS or the sawtooth correction must be converted in a suitable sampled data correction. It is possible even to hardware correct the PPS with a delay line before using it (see the already mentioned gpstime.com/files/tow-time2011.pdf by Tom Clarck and Rick Hambly). On Sat, Feb 11, 2012 at 1:45 PM, Bob Camp li...@rtty.us wrote: Hi Another way to build an analog phase detector... Next layer on the onion is how to get the sawtooth correction out of the GPS and into your loop. Bob On Feb 11, 2012, at 12:05 AM, Chris Albertson albertson.ch...@gmail.com wrote: All these different suggestions build down to one thing, the precision with which you measure the phase when you sample it each second. The single flip flop will tell you which half cycle. a simple two bit counter made with two '74 FFs tells you which half cycle and with direction. The best maybe is if you let the PPS set a FF and the 10MHz reset it. The FF's output gates a constant current to a capacitor and charges it to some voltage. Then you measure that with a 10-bit ADC. This measures the phase to maybe 1%, gives you direction and is pretty cheap to build Let's see if I have the numbers right? If you check a 10MHz signal once per second with just the FF then you have 1E-7. You would need 1000 seconds for 1E-10. But if you measure phase to 1/10th of a cycle you get to 1E-10 ten faster. Right? 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] Leap seconds now showing on GPS satellites
My Z3815A doesn't have a leap second pending... maybe the Furuno GPS receiver hasn't that information or the Z3815A doesn't retrive it. I'll check the HP58503A at work. On Sat, Feb 11, 2012 at 3:52 AM, Hal Murray hmur...@megapathdsl.net wrote: It got here around 2785 seconds UTC after midnight on Feb 10th. (unless I fatfingered something) From a NTP log file while watching a HP Z3801A. The + says insert a leap second. 55967 2401.038 127.127.26.1 T2201202100040023001028 64 0 55967 2465.034 127.127.26.1 T220120210004106300102D 64 0 55967 2529.037 127.127.26.1 T2201202100042103001029 64 0 55967 2593.038 127.127.26.1 T220120210004314300102E 64 0 55967 2657.033 127.127.26.1 T2201202100044183001033 64 0 55967 2721.037 127.127.26.1 T220120210004522300102F 64 0 55967 2785.037 127.127.26.1 T22012021000462630+102F 64 0 55967 2849.033 127.127.26.1 T22012021000473030+102B 64 0 55967 2913.034 127.127.26.1 T22012021000483430+1030 64 0 55967 2977.033 127.127.26.1 T22012021000493830+1035 64 0 55967 3041.033 127.127.26.1 T22012021000504230+1028 64 0 55967 3105.039 127.127.26.1 T22012021000514630+102D 64 0 55967 3169.033 127.127.26.1 T22012021000525030+1029 64 0 55967 3233.033 127.127.26.1 T22012021000535430+102E 64 0 -- 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] Picotest U6200A Timelab
Indeed interesting but the 5370s seem to go for $300-400 and this $1750. I had been lucky to get my 5370s pre-interest price accelerator so $50-75. Because who would ever want such a heavy thing? Much as I love the modern interfaces, size, quite, and low power consumption. The boat anchors stay. ;-) Regards Paul WB8TSL On Sat, Feb 11, 2012 at 8:07 AM, Bob Camp li...@rtty.us wrote: Hi If I hit the Acquire / U6200A entry in the Timelab menu will it buy one for me? How noisy is it? Put another way, it has 40 ps resolution, how close can you get to that in terms of accuracy? Looks like a cool toy, thanks for sharing. Bob On Feb 11, 2012, at 7:52 AM, Ulrich Bangert df...@ulrich-bangert.de wrote: Gentlemen, a few weeks ago a link to a new counter named U6200A was to be found here in the group. I considered the technical properties of this counter (which is sold under the brands Array or Picotest) that interesting at its price that i ordered one immediately. I did not buy it directly from China but instead from a German importer called OSCOMP. They were able to deliver me the counter with a built in GPIB-interface. I had not been able to allocate a seller in China with this option. I am currently testing the counter and as far everything looks pretty good. You can get an impression of the counter's capabilities by the direct comparison to the industry standard here: http://www.stantronic.de/b/Comparison-U6200A.pdf At its price and the 40 ps single shot resolution it may be a good idea to buy such a counter new for time nuts purposes instead of hunting for used 5370s and SR620s. Since the manual claims that the counter features a HP53132 compatible SCPI command languge I tried to run John Miles's Timelab with the counter which failed in the beginning. Due to John's immediate reaction on my inquiry concerning the U6200a Timelab now has its own hardware entry for te U6200A in the Acquire menu and my tests show that Timelab runs like charm with the U6200A. Note that Timelab checks the device id with a *IDN? and the current version recognizes the Picotest brand answer to this. This may be different with the Array brand id. Best regards Ulrich Bangert www.ulrich-bangert.de Ortholzer Weg 1 27243 Gross Ippener Germany ___ 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] GPS lock of the FE5680. Current experiment and question
Getting very interesting. Bob had mentioned just sample the 10 MC sine wave. What I used to do on homebrew Loran C. Thats easier to do because today its nothing to buffer that 10 MC signal to drive a fast sample and hold. This eliminates the ramp circuitry and constant current sources used in the ramp and tempco effects. This all seems to work out reasonably because the 5680s are in general pretty darn stable. (Boy is that a relative term in time-nuts land) Now to dig through the ole junk box for a sample and hold chips. Most likely older and useless. Go hunting at mouser or digikey for modern stuff. Hate to have to go to discrete pulsed diodes. Regards Paul. On Sat, Feb 11, 2012 at 10:33 AM, Azelio Boriani azelio.bori...@screen.itwrote: This is the simplest part if a microprocessor can be used: by the serial port you get the sawtooth correction in nS to be applied to the sampled data. The sampled data must be converted to nS or the sawtooth correction must be converted in a suitable sampled data correction. It is possible even to hardware correct the PPS with a delay line before using it (see the already mentioned gpstime.com/files/tow-time2011.pdf by Tom Clarck and Rick Hambly). On Sat, Feb 11, 2012 at 1:45 PM, Bob Camp li...@rtty.us wrote: Hi Another way to build an analog phase detector... Next layer on the onion is how to get the sawtooth correction out of the GPS and into your loop. Bob On Feb 11, 2012, at 12:05 AM, Chris Albertson albertson.ch...@gmail.com wrote: All these different suggestions build down to one thing, the precision with which you measure the phase when you sample it each second. The single flip flop will tell you which half cycle. a simple two bit counter made with two '74 FFs tells you which half cycle and with direction. The best maybe is if you let the PPS set a FF and the 10MHz reset it. The FF's output gates a constant current to a capacitor and charges it to some voltage. Then you measure that with a 10-bit ADC. This measures the phase to maybe 1%, gives you direction and is pretty cheap to build Let's see if I have the numbers right? If you check a 10MHz signal once per second with just the FF then you have 1E-7. You would need 1000 seconds for 1E-10. But if you measure phase to 1/10th of a cycle you get to 1E-10 ten faster. Right? 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] Removing thermal tape residue?
Is there a recommended way to remove the residue of what I presume was thermal tape on the heatsinks of my various telco Rb units? It's a slightly tacky light greenish layer. I'm guessing that for a permanent installation one would want to remove that residue, smooth the surface, and replace with new material for best thermal transfer to the heatsink. John ___ 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] Removing thermal tape residue?
I wasn't clear below -- the residue is on the Rb exterior surface that attached to the heatsink. On Feb 11, 2012, at 11:52 AM, John Ackermann N8UR j...@febo.com wrote: Is there a recommended way to remove the residue of what I presume was thermal tape on the heatsinks of my various telco Rb units? It's a slightly tacky light greenish layer. I'm guessing that for a permanent installation one would want to remove that residue, smooth the surface, and replace with new material for best thermal transfer to the heatsink. John ___ 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] Removing thermal tape residue?
John, Have you tried anything yet? As a first pass I would try something petroleum based to clean. I know this has worked for me in the past. Rob Kimberley -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of John Ackermann N8UR Sent: 11 February 2012 16:53 To: Time-Nuts Subject: [time-nuts] Removing thermal tape residue? Is there a recommended way to remove the residue of what I presume was thermal tape on the heatsinks of my various telco Rb units? It's a slightly tacky light greenish layer. I'm guessing that for a permanent installation one would want to remove that residue, smooth the surface, and replace with new material for best thermal transfer to the heatsink. John ___ 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] Removing thermal tape residue?
Maybe a thinner can help... On Sat, Feb 11, 2012 at 5:58 PM, Rob Kimberley robkimber...@btinternet.comwrote: John, Have you tried anything yet? As a first pass I would try something petroleum based to clean. I know this has worked for me in the past. Rob Kimberley -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of John Ackermann N8UR Sent: 11 February 2012 16:53 To: Time-Nuts Subject: [time-nuts] Removing thermal tape residue? Is there a recommended way to remove the residue of what I presume was thermal tape on the heatsinks of my various telco Rb units? It's a slightly tacky light greenish layer. I'm guessing that for a permanent installation one would want to remove that residue, smooth the surface, and replace with new material for best thermal transfer to the heatsink. John ___ 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] Removing thermal tape residue?
There is a layer like that on my LPRO-101 that I think is the 'thermal conductor' designed to 'connect' the unit to the heat sink. Or am I disoriented? Joe -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of John Ackermann N8UR Sent: Saturday, February 11, 2012 10:53 AM To: Time-Nuts Subject: [time-nuts] Removing thermal tape residue? Is there a recommended way to remove the residue of what I presume was thermal tape on the heatsinks of my various telco Rb units? It's a slightly tacky light greenish layer. I'm guessing that for a permanent installation one would want to remove that residue, smooth the surface, and replace with new material for best thermal transfer to the heatsink. John ___ 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] Leap seconds now showing on GPS satellites
I was hoping that they would add it at some week rollover point or at the first of the month, etc. But it appears to just be random or whenever they get around to it. Connected by DROID on Verizon Wireless -Original message- From: Hal Murray hmur...@megapathdsl.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sat, Feb 11, 2012 02:52:53 GMT+00:00 Subject: Re: [time-nuts] Leap seconds now showing on GPS satellites It got here around 2785 seconds UTC after midnight on Feb 10th. (unless I fatfingered something) From a NTP log file while watching a HP Z3801A. The + says insert a leap second. 55967 2401.038 127.127.26.1 T2201202100040023001028 64 0 55967 2465.034 127.127.26.1 T220120210004106300102D 64 0 55967 2529.037 127.127.26.1 T2201202100042103001029 64 0 55967 2593.038 127.127.26.1 T220120210004314300102E 64 0 55967 2657.033 127.127.26.1 T2201202100044183001033 64 0 55967 2721.037 127.127.26.1 T220120210004522300102F 64 0 55967 2785.037 127.127.26.1 T22012021000462630+102F 64 0 55967 2849.033 127.127.26.1 T22012021000473030+102B 64 0 55967 2913.034 127.127.26.1 T22012021000483430+1030 64 0 55967 2977.033 127.127.26.1 T22012021000493830+1035 64 0 55967 3041.033 127.127.26.1 T22012021000504230+1028 64 0 55967 3105.039 127.127.26.1 T22012021000514630+102D 64 0 55967 3169.033 127.127.26.1 T22012021000525030+1029 64 0 55967 3233.033 127.127.26.1 T22012021000535430+102E 64 0 -- 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] Removing thermal tape residue?
John: If it is an adhesive tape residue or just an adhesive residue, the best, paint safe, and non-toxic remover I am aware of is Goo-Gone. It is some kind mild solvent with a lot of citrus oil in it. Sold at grocery stores. Since you own a house, I would be surprised if your wife does not already have a bottle. It is impossible to operate a house without it. Works extremely well on adhesive tape residue, stick-on label residue, and windshield sticker residue. If that doesn't work then try iso-propyl alcohol, acetone, tri-chlor, etc. Those are more toxic, will attack plastic and paint, etc. --- Graham / KE9H == On 2/11/2012 10:56 AM, John Ackermann N8UR wrote: I wasn't clear below -- the residue is on the Rb exterior surface that attached to the heatsink. On Feb 11, 2012, at 11:52 AM, John Ackermann N8URj...@febo.com wrote: Is there a recommended way to remove the residue of what I presume was thermal tape on the heatsinks of my various telco Rb units? It's a slightly tacky light greenish layer. I'm guessing that for a permanent installation one would want to remove that residue, smooth the surface, and replace with new material for best thermal transfer to the heatsink. John ___ 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] Removing thermal tape residue?
FWIWI used denatured alcohol and acetone. Just be sure to wear chemical safe gloves and plenty of shop rags. But it comes right off. Fumes are bad too. Let the rags dry out before you put them in the trash. -Brian, WA1ZMS -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Graham / KE9H Sent: Saturday, February 11, 2012 12:11 PM To: time-nuts@febo.com Subject: Re: [time-nuts] Removing thermal tape residue? John: If it is an adhesive tape residue or just an adhesive residue, the best, paint safe, and non-toxic remover I am aware of is Goo-Gone. It is some kind mild solvent with a lot of citrus oil in it. Sold at grocery stores. Since you own a house, I would be surprised if your wife does not already have a bottle. It is impossible to operate a house without it. Works extremely well on adhesive tape residue, stick-on label residue, and windshield sticker residue. If that doesn't work then try iso-propyl alcohol, acetone, tri-chlor, etc. Those are more toxic, will attack plastic and paint, etc. --- Graham / KE9H == On 2/11/2012 10:56 AM, John Ackermann N8UR wrote: I wasn't clear below -- the residue is on the Rb exterior surface that attached to the heatsink. On Feb 11, 2012, at 11:52 AM, John Ackermann N8URj...@febo.com wrote: Is there a recommended way to remove the residue of what I presume was thermal tape on the heatsinks of my various telco Rb units? It's a slightly tacky light greenish layer. I'm guessing that for a permanent installation one would want to remove that residue, smooth the surface, and replace with new material for best thermal transfer to the heatsink. John ___ 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] Removing thermal tape residue?
I've used WD-40 to soften adhesive gunk such that a paper towel can be used to wipe it off. From: John Ackermann N8UR j...@febo.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Cc: Time-Nuts time-nuts@febo.com Sent: Sat, February 11, 2012 11:56:01 AM Subject: Re: [time-nuts] Removing thermal tape residue? I wasn't clear below -- the residue is on the Rb exterior surface that attached to the heatsink. On Feb 11, 2012, at 11:52 AM, John Ackermann N8UR j...@febo.com wrote: Is there a recommended way to remove the residue of what I presume was thermal tape on the heatsinks of my various telco Rb units? It's a slightly tacky light greenish layer. I'm guessing that for a permanent installation one would want to remove that residue, smooth the surface, and replace with new material for best thermal transfer to the heatsink. John ___ 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] GPS lock of the FE5680. Current experiment and question
Looks like analog devices makes a pretty nice sample and hold chip. A bit pricey. But can't really work at 10 MC so that would complicate things On Sat, Feb 11, 2012 at 10:54 AM, paul swed paulsw...@gmail.com wrote: Getting very interesting. Bob had mentioned just sample the 10 MC sine wave. What I used to do on homebrew Loran C. Thats easier to do because today its nothing to buffer that 10 MC signal to drive a fast sample and hold. This eliminates the ramp circuitry and constant current sources used in the ramp and tempco effects. This all seems to work out reasonably because the 5680s are in general pretty darn stable. (Boy is that a relative term in time-nuts land) Now to dig through the ole junk box for a sample and hold chips. Most likely older and useless. Go hunting at mouser or digikey for modern stuff. Hate to have to go to discrete pulsed diodes. Regards Paul. On Sat, Feb 11, 2012 at 10:33 AM, Azelio Boriani azelio.bori...@screen.it wrote: This is the simplest part if a microprocessor can be used: by the serial port you get the sawtooth correction in nS to be applied to the sampled data. The sampled data must be converted to nS or the sawtooth correction must be converted in a suitable sampled data correction. It is possible even to hardware correct the PPS with a delay line before using it (see the already mentioned gpstime.com/files/tow-time2011.pdf by Tom Clarck and Rick Hambly). On Sat, Feb 11, 2012 at 1:45 PM, Bob Camp li...@rtty.us wrote: Hi Another way to build an analog phase detector... Next layer on the onion is how to get the sawtooth correction out of the GPS and into your loop. Bob On Feb 11, 2012, at 12:05 AM, Chris Albertson albertson.ch...@gmail.com wrote: All these different suggestions build down to one thing, the precision with which you measure the phase when you sample it each second. The single flip flop will tell you which half cycle. a simple two bit counter made with two '74 FFs tells you which half cycle and with direction. The best maybe is if you let the PPS set a FF and the 10MHz reset it. The FF's output gates a constant current to a capacitor and charges it to some voltage. Then you measure that with a 10-bit ADC. This measures the phase to maybe 1%, gives you direction and is pretty cheap to build Let's see if I have the numbers right? If you check a 10MHz signal once per second with just the FF then you have 1E-7. You would need 1000 seconds for 1E-10. But if you measure phase to 1/10th of a cycle you get to 1E-10 ten faster. Right? 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] Removing thermal tape residue?
Perhaps goof off would work ? I've never used it on electronics but it seems to do a good job removing residue from metal trim in buildings. I expect there are hazards associated with this product so please take suitable pre cautions. -- On Sat, 11 Feb, 2012 12:03 PM EST Azelio Boriani wrote: Maybe a thinner can help... On Sat, Feb 11, 2012 at 5:58 PM, Rob Kimberley robkimber...@btinternet.comwrote: John, Have you tried anything yet? As a first pass I would try something petroleum based to clean. I know this has worked for me in the past. Rob Kimberley -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of John Ackermann N8UR Sent: 11 February 2012 16:53 To: Time-Nuts Subject: [time-nuts] Removing thermal tape residue? Is there a recommended way to remove the residue of what I presume was thermal tape on the heatsinks of my various telco Rb units? It's a slightly tacky light greenish layer. I'm guessing that for a permanent installation one would want to remove that residue, smooth the surface, and replace with new material for best thermal transfer to the heatsink. John ___ 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] Leap seconds now showing on GPS satellites
The words leap second pending are not specific enough and I hope there aren't still GPS receivers or API's that do this. What most applications only want to know is leap second pending this month. Some applications need to know is leap second pending in future month X. So one has to be careful how you handle this information. There is always that awkward time, which we are now in, between when a future leap second is announced and the actual month in which it occurs. It never fails that some user or software misinterprets the IERS or GPS leap second announcement and adds a leap second at the end of one or more months prior to the correct one. Be especially careful about accidental leap seconds on 3/31/2012. The information given by GPS is very specific and allows maximum notice, as we have seen. Some services, like ACTS and WWVB, cannot give more than one month of notice. So when they finally turn on their LS bit, it can only mean leap second pending at the end of this month, which is fine. /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] Leap seconds now showing on GPS satellites
I was hoping that they would add it at some week rollover point or at the first of the month, etc. But it appears to just be random or whenever they get around to it. Leap seconds are always applied at the end of the UTC day of the last day of the month specified. So the next one will occur on July 1 for most of the people in the world and early evening of June 30 for those of us in the USA. When leap seconds are calculated and formally announced is sort of arbitrary and erratic, not unlike how the earth itself rotates. It's not a problem really. No software should care or depend on some precise date of announcement. /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] Removing thermal tape residue?
Thanks, Brian. Sounds like a plan. I just wasn't sure if there was anything special about the thermal material, as I've never worked with it before. BTW -- when you search for thermal tape most of the hits are for the tiny square pads used on CPU heatsinks, but I did find one eBay seller with 100x200mm sheets, albeit with adhesive on only one side -- check item http://www.ebay.com/itm/320834206191?ssPageName=STRK:MEWNX:IT_trksid=p3984.m1497.l2649 John Brian, WA1ZMS said the following on 02/11/2012 12:25 PM: FWIWI used denatured alcohol and acetone. Just be sure to wear chemical safe gloves and plenty of shop rags. But it comes right off. Fumes are bad too. Let the rags dry out before you put them in the trash. -Brian, WA1ZMS -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Graham / KE9H Sent: Saturday, February 11, 2012 12:11 PM To: time-nuts@febo.com Subject: Re: [time-nuts] Removing thermal tape residue? John: If it is an adhesive tape residue or just an adhesive residue, the best, paint safe, and non-toxic remover I am aware of is Goo-Gone. It is some kind mild solvent with a lot of citrus oil in it. Sold at grocery stores. Since you own a house, I would be surprised if your wife does not already have a bottle. It is impossible to operate a house without it. Works extremely well on adhesive tape residue, stick-on label residue, and windshield sticker residue. If that doesn't work then try iso-propyl alcohol, acetone, tri-chlor, etc. Those are more toxic, will attack plastic and paint, etc. --- Graham / KE9H == On 2/11/2012 10:56 AM, John Ackermann N8UR wrote: I wasn't clear below -- the residue is on the Rb exterior surface that attached to the heatsink. On Feb 11, 2012, at 11:52 AM, John Ackermann N8URj...@febo.com wrote: Is there a recommended way to remove the residue of what I presume was thermal tape on the heatsinks of my various telco Rb units? It's a slightly tacky light greenish layer. I'm guessing that for a permanent installation one would want to remove that residue, smooth the surface, and replace with new material for best thermal transfer to the heatsink. John ___ 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] Leap seconds now showing on GPS satellites
In message 34D15475EDD248D49D30FD70F9D927E4@pc52, Tom Van Baak writes: What most applications only want to know is leap second pending this month. Some applications need to know is leap second pending in future month X. Actually, there is a very important application that wants to know as far in advance as possible: the Tell the humans application. -- 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] Removing thermal tape residue?
On 02/11/12 04:52 PM, John Ackermann N8UR wrote: Is there a recommended way to remove the residue of what I presume was thermal tape on the heatsinks of my various telco Rb units? It's a slightly tacky light greenish layer. I'm guessing that for a permanent installation one would want to remove that residue, smooth the surface, and replace with new material for best thermal transfer to the heatsink. John Silicon oil seems to remove that easily. I've found two recent sources of silicon oil when I needed to do this. 1) My mate had some with his electric shaver. 2) Oil filled Bird dummy load. -- A: Because it messes up the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail? ___ 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] GPS lock of the FE5680. Current experiment and question
How about using the 10KHz output from one of the Jupiter receivers as per James Miller's simple GPSDO? There's TU60s available on Ebay from China right now at reasonable prices. regards Nigel GM8PZR In a message dated 11/02/2012 18:04:22 GMT Standard Time, paulsw...@gmail.com writes: Looks like analog devices makes a pretty nice sample and hold chip. A bit pricey. But can't really work at 10 MC so that would complicate things ___ 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] Removing thermal tape residue?
And how do you remove the silicone oil? Ever heard the one about the hotel guest who complains about the mouse in his room? -John === On 02/11/12 04:52 PM, John Ackermann N8UR wrote: Is there a recommended way to remove the residue of what I presume was thermal tape on the heatsinks of my various telco Rb units? It's a slightly tacky light greenish layer. I'm guessing that for a permanent installation one would want to remove that residue, smooth the surface, and replace with new material for best thermal transfer to the heatsink. John Silicon oil seems to remove that easily. I've found two recent sources of silicon oil when I needed to do this. 1) My mate had some with his electric shaver. 2) Oil filled Bird dummy load. -- A: Because it messes up the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail? ___ 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] GPS lock of the FE5680. Current experiment and question
There are no temperature coefficient effects or calibration drift with the current sources and ramp circuits in this case. Between 1 PPS measurements, there is more than enough time to gate a sample waveform from the convenient 10 MHz source to the time to voltage converter to calibrate it. One interesting thing I just noticed with the Tektronix 2440 design is that the trigger starts two different time to voltage converters. One measures to the positive sample clock edge and the other to the negative sample clock edge so if one goes metastable, the other can be used. On Sat, 11 Feb 2012 10:54:40 -0500, paul swed paulsw...@gmail.com wrote: Getting very interesting. Bob had mentioned just sample the 10 MC sine wave. What I used to do on homebrew Loran C. Thats easier to do because today its nothing to buffer that 10 MC signal to drive a fast sample and hold. This eliminates the ramp circuitry and constant current sources used in the ramp and tempco effects. This all seems to work out reasonably because the 5680s are in general pretty darn stable. (Boy is that a relative term in time-nuts land) Now to dig through the ole junk box for a sample and hold chips. Most likely older and useless. Go hunting at mouser or digikey for modern stuff. Hate to have to go to discrete pulsed diodes. Regards On Sat, Feb 11, 2012 at 10:33 AM, Azelio Boriani azelio.bori...@screen.itwrote: This is the simplest part if a microprocessor can be used: by the serial port you get the sawtooth correction in nS to be applied to the sampled data. The sampled data must be converted to nS or the sawtooth correction must be converted in a suitable sampled data correction. It is possible even to hardware correct the PPS with a delay line before using it (see the already mentioned gpstime.com/files/tow-time2011.pdf by Tom Clarck and Rick Hambly). On Sat, Feb 11, 2012 at 1:45 PM, Bob Camp li...@rtty.us wrote: Another way to build an analog phase detector... Next layer on the onion is how to get the sawtooth correction out of the GPS and into your loop. On Feb 11, 2012, at 12:05 AM, Chris Albertson albertson.ch...@gmail.com wrote: All these different suggestions build down to one thing, the precision with which you measure the phase when you sample it each second. The single flip flop will tell you which half cycle. a simple two bit counter made with two '74 FFs tells you which half cycle and with direction. The best maybe is if you let the PPS set a FF and the 10MHz reset it. The FF's output gates a constant current to a capacitor and charges it to some voltage. Then you measure that with a 10-bit ADC. This measures the phase to maybe 1%, gives you direction and is pretty cheap to build Let's see if I have the numbers right? If you check a 10MHz signal once per second with just the FF then you have 1E-7. You would need 1000 seconds for 1E-10. But if you measure phase to 1/10th of a cycle you get to 1E-10 ten faster. 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.
[time-nuts] GPS noise plots
Nothing new or exciting here, but I did some measurements of three GPS sources -- M12+/TAC2, M12+/CNS Clock II with sawtooth correction, and Z3801A -- to see what their short-term noise looked like, and got some pretty pictures: http://www.febo.com/pages/gps_pps/index.html Thanks to John Miles' wonderful, excellent TimeLab software, it's ridiculously easy now to do this sort of data collection. I add a couple more superlatives and throw in an exclamation point if only it worked under Linux.* :-) John * A first attempt to run it under Wine resulted in an error before even getting the window open; haven't had a chance yet to see if that can be worked around. ___ 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] Leap seconds now showing on GPS satellites
On 02/11/2012 07:40 PM, Tom Van Baak wrote: I was hoping that they would add it at some week rollover point or at the first of the month, etc. But it appears to just be random or whenever they get around to it. Leap seconds are always applied at the end of the UTC day of the last day of the month specified. So the next one will occur on July 1 for most of the people in the world and early evening of June 30 for those of us in the USA. When leap seconds are calculated and formally announced is sort of arbitrary and erratic, not unlike how the earth itself rotates. It's not a problem really. No software should care or depend on some precise date of announcement. I think he was talking about the time to upload the announcement of the upcoming leap second. Doing it when they get around to it seems just fine, it is done well in advance anyway. Cheers, Magnus ___ 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] Removing thermal tape residue?
Try searching for thermally conductive adhesive gap filler to get a good selection of manufacturers like Bergquist, Chomerics, Masterbond, etc. From: John Ackermann N8UR j...@febo.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sat, February 11, 2012 1:45:08 PM Subject: Re: [time-nuts] Removing thermal tape residue? ... BTW -- when you search for thermal tape most of the hits are for the tiny square pads used on CPU heatsinks... ___ 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] Removing thermal tape residue?
I can confirm: my LPRO-101 has this thermal conductive green sheet too. I think to retain it instead of getting rid but it is not in perfect shape... On Sun, Feb 12, 2012 at 12:18 AM, Robert LaJeunesse rlajeune...@sbcglobal.net wrote: Try searching for thermally conductive adhesive gap filler to get a good selection of manufacturers like Bergquist, Chomerics, Masterbond, etc. From: John Ackermann N8UR j...@febo.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sat, February 11, 2012 1:45:08 PM Subject: Re: [time-nuts] Removing thermal tape residue? ... BTW -- when you search for thermal tape most of the hits are for the tiny square pads used on CPU heatsinks... ___ 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] Morion MV89A pics
As requested, pics of the inside of my Morion XO00281M-CT-MV89 MV89A double oven ultra precision OCXO, serial ZA5310, date 03/22. Sorry, I didn't feel like peeling apart the outer oven. Small pics (~50 kB): http://n5tnl.com/time/mv89a/mv89a_1_small.jpg http://n5tnl.com/time/mv89a/mv89a_2_small.jpg http://n5tnl.com/time/mv89a/mv89a_3_small.jpg http://n5tnl.com/time/mv89a/mv89a_4_small.jpg Big pics (~5 MB): http://n5tnl.com/time/mv89a/mv89a_1.png http://n5tnl.com/time/mv89a/mv89a_2.png http://n5tnl.com/time/mv89a/mv89a_3.png http://n5tnl.com/time/mv89a/mv89a_4.png There was some oddly soft and fluffy cotton like insulation between the top of the outer oven and the can. -- newell N5TNL ___ 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] Literature on low noise and HF electronics
The appnotes from LT especially Jim Williams articles. LT used to print these in book form. Check out the V to F designs, and the data acquisition stuff. Very practical with real world components and test results. Very high end analog stuff. Most textbooks are totally useless, the authors trying to hide their lack of real world experience with lots of math and theory. Also Bob Pease published some books through EDN quite good also. Bye Said Sent From iPhone On Feb 11, 2012, at 0:43, Attila Kinali att...@kinali.ch wrote: Moin, The recent discussions have made it again clear to me, that i lack a lot of knowledge in electronics. Especially when it comes to the black arts: analog stuff, HF, getting the most ouf of a transistor, or doing it really really low noise. Could someone recomend anything to read that would get me more insights and knowledge on these topics? May it be books, papers or search terms for google. Thanks in advance Attila Kinali -- Why does it take years to find the answers to the questions one should have asked long ago? ___ 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] Literature on low noise and HF electronics
Forgot to mention: Searching amazon for Jim Williams returns a number of great books by Jim and Bob Pease.. Sent From iPhone On Feb 11, 2012, at 20:00, Said Jackson saidj...@aol.com wrote: The appnotes from LT especially Jim Williams articles. LT used to print these in book form. Check out the V to F designs, and the data acquisition stuff. Very practical with real world components and test results. Very high end analog stuff. Most textbooks are totally useless, the authors trying to hide their lack of real world experience with lots of math and theory. Also Bob Pease published some books through EDN quite good also. Bye Said Sent From iPhone On Feb 11, 2012, at 0:43, Attila Kinali att...@kinali.ch wrote: Moin, The recent discussions have made it again clear to me, that i lack a lot of knowledge in electronics. Especially when it comes to the black arts: analog stuff, HF, getting the most ouf of a transistor, or doing it really really low noise. Could someone recomend anything to read that would get me more insights and knowledge on these topics? May it be books, papers or search terms for google. Thanks in advance Attila Kinali -- Why does it take years to find the answers to the questions one should have asked long ago? ___ 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] Literature on low noise and HF electronics
On 2/11/12 8:00 PM, Said Jackson wrote: The appnotes from LT especially Jim Williams articles. LT used to print these in book form. Check out the V to F designs, and the data acquisition stuff. Very practical with real world components and test results. Very high end analog stuff. Most textbooks are totally useless, the authors trying to hide their lack of real world experience with lots of math and theory. Also Bob Pease published some books through EDN quite good also. indeed.. ap notes are your friend, esp on design. There is so much art in low noise design getting ultimate performance is all about the individual devices, and fiddling with it to find what works for it. ___ 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] Leap seconds now showing on GPS satellites
t...@leapsecond.com said: So one has to be careful how you handle this information. There is always that awkward time, which we are now in, between when a future leap second is announced and the actual month in which it occurs. It never fails that some user or software misinterprets the IERS or GPS leap second announcement and adds a leap second at the end of one or more months prior to the correct one. I just checked the user manual for the Z3801A. I didn't find anything about when the leap second will happen. Last time we had one, I fixed the NTP driver for the Z3801A so it would ignore leap-pending except if the current month was June or December. I considered doing something more complicated, but that seemed more likely to introduce bugs. I predict things will get interesting when the IERS announces the first leap second in March or September. Anybody want to guess how many Z3801As will still be running then? That driver also works with the HP/Agilent 58503A. They will probably be around longer. Symmetricom didn't drop the 58503B until 2008. -- 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.
