[time-nuts] Name of integral of timing residual
Folks, I'm after the formal name of something (if it exists), and this group, if any, should know. Consider a plot of a timing residual vs time. Say a watch against a maser, residual=watch-maser. Now if I now plot the cumulative sum (think integral) of the residual, that's going to give me an overall view of how the clock is performing over time. (If it helps, think of PID controllers and how they work in the "I" part.) Now if you look at *motion* of an object over time, and you integrate its acceleration you get velocity, integrate again you get displacement. Integrate again and you get "absement" and again you get "abcity" (I only recently discovered these terms). Does the integral of a timing residual have a name, and does the integral of *that* have a name as well? Any thoughts? Jim Palfreyman ___ 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] Measuring coax temperature coefficient with a TICC
most likely the cooper is much ticker than the penetration of the lowest frequency for which the cable is used, therefore the high frequency "does not" see the steel inside of the cooper, that steel could cause problem if the coax also used to carry some power -- DC or AC -- because at lower frequency or DC the cable's current carried mostly in the cooper, and while the cooper constitute just a small fraction of the center wire cross section, a cable with "steel core" could carry much less current, than a cable with full cooper. But the steel core cable has one advantage it is usually stronger than a full cooper cable and therefore it is usable for outside installation with larger support distance. 73 KJ6UHN, [a former engineer of a cable manufacturer ] Alex On 4/19/2017 11:57 AM, Hal Murray wrote: kb...@n1k.org said: I’d want to be pretty sure what the center conductor was made out of. I’ve seen some stuff in coax that “one would think� should not be there (copper over steel …). Does that effect the propagation time? If I gave you a good scope picture of a pulse after going through chunk of coax, could you figure out the ratio of copper to steel? Would you need to know the length or could you figure that out too? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. - No virus found in this message. Checked by AVG - www.avg.com Version: 2016.0.8012 / Virus Database: 4769/14347 - Release Date: 04/19/17 ___ 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] Measuring coax temperature coefficient with a TICC
A table of a bunch of rg6 catv permutations, http://www.texcan.com/media/import/pdf/Electronic_Cable_RG6_RG59.pdf At least on this list if it has a solid copper core, it also has a copper braid shield. I'm sure there is many more permutations out there. On Wed, Apr 19, 2017 at 7:00 PM Will Kimber wrote: > TV co-ax these days for satellite or UHF is almost all steel wire with > copper plating. In fact the 'F' connector that is used is designed to > use that stiff wire as the center pin of the connector! > > > Will > > > On 04/20/2017 06:57 AM, Hal Murray wrote: > > kb...@n1k.org said: > >> I’d want to be pretty sure what the center conductor was made out of. > I’ve > >> seen some stuff in coax that “one would think†should not be there > (copper > >> over steel …). > > Does that effect the propagation time? > > > > If I gave you a good scope picture of a pulse after going through chunk > of > > coax, could you figure out the ratio of copper to steel? Would you need > to > > know the length or could you figure that out too? > > > > > > > > ___ > > time-nuts mailing list -- time-nuts@febo.com > > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > > ___ > 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] Measuring coax temperature coefficient with a TICC
MMmm interesting but what about skindepth ?? surely the "R" is not DC R so would it matter? RF currents travelling in the copper anyway. I suspect that a steel inner might increase the L/unit length?, maybe this is more significant or not as is sceened by copper?? Alan G3NYK - Original Message - From: "jimlux" To: Sent: Wednesday, April 19, 2017 11:17 PM Subject: Re: [time-nuts] Measuring coax temperature coefficient with a TICC On 4/19/17 11:57 AM, Hal Murray wrote: kb...@n1k.org said: I’d want to be pretty sure what the center conductor was made out of. I’ve seen some stuff in coax that “one would think†should not be there (copper over steel …). Does that effect the propagation time? If I gave you a good scope picture of a pulse after going through chunk of coax, could you figure out the ratio of copper to steel? Would you need to know the length or could you figure that out too? This being timenuts, I think you might do it with just timing measurements. Let's see - the different candidate materials all have different thermal resistance coefficients. So you can make some DC measurements. If you knew it was some combination of copper and steel, for instance, you could probably determine the ratio from that alone (or, for that matter, doing it at a single temperature, if you can *measure* the diameter of the conductor). There is some variation in material properties (not all copper is the same, and, in particular, steel varies widely depending on alloy and manufacturing). The propagation equation has a dependence on both R and G as well as L and C Is the change in prop speed due to the change in R bigger or smaller than the change due to L and C (from dimensional changes)? The L and C terms both have a frequency dependent (linear in frequency) term. The R term has a fairly complex dependency on frequency, in terms of skin depth relative to the diameter of the conductor. The G term also has a frequency dependence. ___ 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] Measuring coax temperature coefficient with a TICC
Hi > On Apr 19, 2017, at 2:57 PM, Hal Murray wrote: > > > kb...@n1k.org said: >> I’d want to be pretty sure what the center conductor was made out of. I’ve >> seen some stuff in coax that “one would think” should not be there (copper >> over steel …). > > Does that effect the propagation time? > > If I gave you a good scope picture of a pulse after going through chunk of > coax, could you figure out the ratio of copper to steel? Would you need to > know the length or could you figure that out too? > The issue is skin depth. On something like TV coax operated at the normal frequencies, a copper jacket is likely as good as full coper. The skin depth is such that the signals never “see” the iron core to any real extent. With a pulse that has a fast edge things are quite so cut and dried. Most of the “signal” that you are measuring in that fast rising edge is at high frequencies. That would suggest that the skin depth stuff would get you there as well. Best way to do it would be at low frequencies either DC or a LF sine wave. Bob > -- > These are my opinions. 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] Measuring coax temperature coefficient with a TICC
TV co-ax these days for satellite or UHF is almost all steel wire with copper plating. In fact the 'F' connector that is used is designed to use that stiff wire as the center pin of the connector! Will On 04/20/2017 06:57 AM, Hal Murray wrote: > kb...@n1k.org said: >> I’d want to be pretty sure what the center conductor was made out of. >> I’ve >> seen some stuff in coax that “one would think� should not be there >> (copper >> over steel …). > Does that effect the propagation time? > > If I gave you a good scope picture of a pulse after going through chunk of > coax, could you figure out the ratio of copper to steel? Would you need to > know the length or could you figure that out too? > > > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ 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] Measuring coax temperature coefficient with a TICC
On 4/19/17 11:57 AM, Hal Murray wrote: kb...@n1k.org said: I’d want to be pretty sure what the center conductor was made out of. I’ve seen some stuff in coax that “one would think†should not be there (copper over steel …). Does that effect the propagation time? If I gave you a good scope picture of a pulse after going through chunk of coax, could you figure out the ratio of copper to steel? Would you need to know the length or could you figure that out too? This being timenuts, I think you might do it with just timing measurements. Let's see - the different candidate materials all have different thermal resistance coefficients. So you can make some DC measurements. If you knew it was some combination of copper and steel, for instance, you could probably determine the ratio from that alone (or, for that matter, doing it at a single temperature, if you can *measure* the diameter of the conductor). There is some variation in material properties (not all copper is the same, and, in particular, steel varies widely depending on alloy and manufacturing). The propagation equation has a dependence on both R and G as well as L and C Is the change in prop speed due to the change in R bigger or smaller than the change due to L and C (from dimensional changes)? The L and C terms both have a frequency dependent (linear in frequency) term. The R term has a fairly complex dependency on frequency, in terms of skin depth relative to the diameter of the conductor. The G term also has a frequency dependence. ___ 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] Measuring coax temperature coefficient with a TICC
Particularly if the cable / wire was made in say the last 10 years. I've seen a LOT of magnetic supposedly 100% pure (oxygen free, of course) copper wire lately. Much of it branded by companies with a reputation to lose. It has gotten so bad, I now check the resistance of all the wire I buy with my HP-3458A. A couple of local sellers now have me vet all their wire purchases. I've seen wire with a resistance over 3 times what copper should be. It's particularly scary to see that in wiring sold for mains wiring. > I’d want to be pretty sure what the center conductor was made out of. I’ve > seen some stuff in coax that “one would think” should not be there (copper over steel …). ___ 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] Measuring coax temperature coefficient with a TICC
kb...@n1k.org said: > Iâd want to be pretty sure what the center conductor was made out of. Iâve > seen some stuff in coax that âone would thinkâ should not be there (copper > over steel â¦). Does that effect the propagation time? If I gave you a good scope picture of a pulse after going through chunk of coax, could you figure out the ratio of copper to steel? Would you need to know the length or could you figure that out too? -- These are my opinions. 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] Measuring coax temperature coefficient with a TICC
Although I didn't have a way to log the temperature, I did have a couple of thermocouples on the coil of coax. The coil was rather tightly wound... maybe 7" OD, 3"ID, and 3" tall. One thermocouple was on the outside and one buried in the center of the coil. They stayed within a couple of degrees of each other. Coax in that configuration seems to be rather thermally "dense". It took over 2 hours to approach room temperature equilibrium in open air. I suspect the results would be quite a bit different with coax on a spool with a much greater surface area to volume ratio. I want to try it again with the coil well insulated and chilled overnight. > A single sensor will only give you precise information if the temperature > ramp is *very* slow (as in days …). ___ 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] Measuring coax temperature coefficient with a TICC
Hi One of the easiest ways to get a slow ramp it to toss the foam box full of cable out the back door. Assuming it stays in the shade, you can often get a pretty good 24 hour temperature cycle. You still need to monitor things to know what the ramp is. Generally it’s slow enough that you can be pretty sure everything is isothermal during the test. Yes, there are some practical issues with doing it this way (thunderstorms, cables to hook it up, bugs, alligators ….) Bob > On Apr 19, 2017, at 9:01 AM, Mark Sims wrote: > > Yes, for a variety of reasons, I would not expect the best results with coax > on a spool. The coax that I tested was a loose coil of coax pre-fabbed with > BNC connectors. It should not have any significant stresses on it than a > laid out 100 foot run would. The main purpose of the experiment was just to > see how well the TICC could detect temperature effects on a hunk of coax. I > just found a small styrofoam insulated shipping box (I think it might have > been used for shipping pies) that should make for a better cable testing box. > > > >> I would question how much the results will relate to real-world use of coax, >> where its not > normal to have great real of 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. ___ 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] Measuring coax temperature coefficient with a TICC
Yes, for a variety of reasons, I would not expect the best results with coax on a spool. The coax that I tested was a loose coil of coax pre-fabbed with BNC connectors. It should not have any significant stresses on it than a laid out 100 foot run would. The main purpose of the experiment was just to see how well the TICC could detect temperature effects on a hunk of coax. I just found a small styrofoam insulated shipping box (I think it might have been used for shipping pies) that should make for a better cable testing box. > I would question how much the results will relate to real-world use of coax, > where its not normal to have great real of 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] Measuring coax temperature coefficient with a TICC
On 4/19/17 3:34 AM, Bob kb8tq wrote: Hi On Apr 18, 2017, at 8:33 PM, jimlux wrote: On 4/18/17 3:55 PM, Bob kb8tq wrote: Hi On something like a 500’ spool of coax, the question will always be “what temperature is it where in the spool”. A single sensor will only give you precise information if the temperature ramp is *very* slow (as in days …). measure the DC resistance of the spool, and you'll be able to get a sort of "average" temperature. I’d want to be pretty sure what the center conductor was made out of. I’ve seen some stuff in coax that “one would think” should not be there (copper over steel …). One would want to calibrate your "coax as temp sensor" just in case you've got some exotic stuff with silver plated over stainless steel (used in cryo applications). But you could probably do that with a short length. Copper is about 0.4% /degree Iron is about 0.6% So, over a -10 to 60 degree swing you'd see about significant (30-40%) change in the resistance, and it would be easy to tell if it's copper or iron or NiCr or something really exotic. The Belden catalog says that RG58/U type coax is about 7-8 ohms/1000 ft. So a 10 foot length is 0.07 ohms - A bit tricky to measure that low, but not impossible, and certainly within the scope of a time-nut skilled in the electronics arts. ___ 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] Measuring coax temperature coefficient with a TICC
On 15 April 2017 at 02:34, Mark Sims wrote: > I finally got around to using a TICC to measure the temperature > coefficient of 100 feet of generic RG-58 coax using a TICC. The TICC was > clocked by a HP 5071A 10 MHz output. The 1PPS output was connected to the > input of the coax and the TICC chB input. The TICC chA input was connected > to the coax output via an inline terminator. The TICC was set to "debug" > mode and Lady Heather plotted the chB-chA timestamp difference (hence the > negative cable delay values). > > The coax had been chilled down for 2 hours in a 5 degrees F in a freezer, > connected to the TICC, and left to warm up in a 75 degree F room. Over > the 10F to 70F temperature range (measured with an IR thermometer) the coax > delay spanned around 300 ps... so figure around 5 ps per degree F (10 ps > per degree C) for 100 feet of cable. > > I'm adding currently adding the ability for Heather to use an external > temperature sensor... > I would not assume that a reel of coax that is coiled up will behave the same as when used in in a lab environment in the usual way. So whilst this might be an interesting experiment, I believe some caution would need to be applied before assuming that such a measurement is representative of how coax is normally used. When not on a reel, a heated coax is free to expand radially with no external pressure force applied, apart from that due to air pressure. When on a reel, that's not the case, as the coax is the middle of the reel is going to have forces applied that are much greater due to the mass of the coax. To take an extreme example, if you use a foam dielectric coax, when on a real, the airgaps in the foam are likely to become smaller as the cable will experience mechanical forces as it tries to expand, constrained by the coax around it. Also, when the coax tries to expand under heat, it is likely to deform to take up the space between the turns on the reel, so possibly become more square. Unfortunately cable is likely to behave very differently at 10 MHz than 10 GHz, so it not necessarily useful to repeat a measurement with a small piece of coax at 10 GHz, where its phase change could easily be measured on a vector network analyzer. Another spanner in the works is that the impedance of coax (usually 50 Ohms), is given by the equation Z=sqrt( (R + 2 pi f L)/(G + 2 Pi f C) ) where R is the resistance per unit length, L is the inductance per unit length, G is the conductance per unit length and C is the capacitance per unit length. The high frequency approximation is that 2 pi f L >> R, and 2 Pi f C >> G, so it simplifies to sqrt(L/C). Those two assumptions become less valid at low frequencies. Overall, what you are doing seems interesting, but I would question how much the results will relate to real-world use of coax, where its not normal to have great real of it. Dr. David Kirkby Ph.D CEng MIET Kirkby Microwave Ltd Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, Essex, CM3 6DT, UK. Registered in England and Wales, company number 08914892. http://www.kirkbymicrowave.co.uk/ Tel: 07910 441670 / +44 7910 441670 (0900 to 2100 GMT only please) ___ 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] Measuring coax temperature coefficient with a TICC
Hi > On Apr 18, 2017, at 8:33 PM, jimlux wrote: > > On 4/18/17 3:55 PM, Bob kb8tq wrote: >> Hi >> >> On something like a 500’ spool of coax, the question will always be “what >> temperature is it where in the spool”. A single sensor will >> only give you precise information if the temperature ramp is *very* slow (as >> in days …). >> > > measure the DC resistance of the spool, and you'll be able to get a sort of > "average" temperature. I’d want to be pretty sure what the center conductor was made out of. I’ve seen some stuff in coax that “one would think” should not be there (copper over steel …). Bob > > > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ 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.
