[time-nuts] Re: Water in connectors
Ah, yes. The wonderful thing about our modern science (and the toys that arise from it) is that there is a bottomless treasure trove of interesting things to investigate. It occurred to me that one could expand a bit on Bob's point to include the probable variation of water's dielectric constant when it goes between liquid and solid states. I once had a big problem with a 2m repeater's transmission line wherein a connector near the bottom end "filled" with water. I think the amount was little more than a ml, but its effect was to bring the repeater to its knees. I unscrewed the connector, drained a few drops from it, dried it with a hanky, and all was back to normal upon reassembly. This should not be too surprising considering water's dielectric constant of around 80. Good luck with your own investigations. Dana On Sat, Mar 27, 2021 at 11:53 AM Ole Petter Rønningen wrote: > Oh, no qustion that it would be interesting, but I’d hate to «tie up» the > gear for a month on a low cost patch antenna, when I have a much better one > temorarily taken down - basically I just wanted a quick check of how much > worse things are on «low end gear» - somewhat predictably that only served > to uncover more questions than it answered.. > > > 27. mar. 2021 kl. 17:39 skrev Dana Whitlow : > > > > My own belief is that almost everything can be blamed on GPS, but then > much > > if not > > most is my own fault for using an indoor antenna only about 6 or 7 feet > > above ground > > level. > > > > Except when excessive lightning activity is around, I run a > > continuous setup comparing > > 10 MHz phase between a T'Bolt GPSDO and a Rb, showing I & Q waveforms on > a > > very > > slow roll-mode 'scope display which shows the most recent 4 hours. It > just > > sits there > > and runs, and I glance at it many times per day in passing. It gets very > > messy much > > of the time. > > > > A month-long recording could net you quite a bit of couch time :-) > > > > Dana > > > > > >> On Sat, Mar 27, 2021 at 11:21 AM Ole Petter Rønningen < > opronnin...@gmail.com> > >> wrote: > >> > >> Active HM, yes - nothing in the logs that corresponds, except a .5 degC > >> diurnal temperature change - which roughly coincides with the outdoor > temp, > >> so no help there.. > >> > >> This was meant as a quick-and-dirty check, so a months is not in the > cards > >> - but that second antenna/receiver is climbing on my list of > priorities, in > >> imminent danger of surpassing «doing nothing on the couch»! :) > >> > 27. mar. 2021 kl. 16:52 skrev Dana Whitlow : > >>> > >>> Ole, > >>> > >>> If you can stand the suspense, a time error recording of a month or > more > >>> duration > >>> would probably be pretty informative (and interesting for us to see). > >>> > >>> And when you speak of the maser, is that an active hydrogen maser? If > >> so, > >>> you're > >>> a lucky man (unless it's in the process of dying). But there should be > >>> scads of > >>> diagnostics being logged, which should be enough to enable making a > >> fairly > >>> good > >>> confidence check on it. > >>> > >>> Dana > >>> > >>> > On Sat, Mar 27, 2021 at 8:33 AM Ole Petter Rønningen < > >> opronnin...@gmail.com> > wrote: > > Hi, Dana > > Thats the peculiar thing - these last 48 hors theres been a pretty > clear > 24 hour cycle, pointing to temperature as the culprit; but the > >> preceeding > 48 hours the phase shift did not follow a 24 hour period at all; the > wheather has been all over the place, so it is hard to say.. More data > needed! As always.. > > (of course, there is always a possibility that I’ve somehow bungled > the > data, and the period has been 24 hours all along) > > This is why I am looking for ballpark figures for the two main > suspects; > water and temperature. > > I guess I should bite the bullet and rig up a second receiver/antenna > >> so I > can take the maser out of the equation.. (and reseal the connectors > properly) > > > >> 27. mar. 2021 kl. 14:04 skrev Dana Whitlow : > > > > Ole, > > > > You did not mention whether this timing anomaly is periodic or > steadily > > growing. > > That information could be of considerable diagnostic significance. > > > > Dana > > > > > >> On Sat, Mar 27, 2021 at 6:08 AM Ole Petter Ronningen < > opronnin...@gmail.com> > >> wrote: > >> > >> Hi, All > >> > >> I am trying to chase down a 2-3-4 ns/day "anomaly" in a gpsdo I am > working > >> on - it could be temperature sensitivity in the antenna (cheap patch > >> jobbie), or I suspect my sealing of the outside connectors may not > be > >> watertight. I just wanted to ask the list of anyone know of/has an > estimate > >> of how much the propagation delay on an N and/or SMA can reasonably > be > >> expected to change in the presence of water? is 3
[time-nuts] Re: Water in connectors
Oh, no qustion that it would be interesting, but I’d hate to «tie up» the gear for a month on a low cost patch antenna, when I have a much better one temorarily taken down - basically I just wanted a quick check of how much worse things are on «low end gear» - somewhat predictably that only served to uncover more questions than it answered.. > 27. mar. 2021 kl. 17:39 skrev Dana Whitlow : > > My own belief is that almost everything can be blamed on GPS, but then much > if not > most is my own fault for using an indoor antenna only about 6 or 7 feet > above ground > level. > > Except when excessive lightning activity is around, I run a > continuous setup comparing > 10 MHz phase between a T'Bolt GPSDO and a Rb, showing I & Q waveforms on a > very > slow roll-mode 'scope display which shows the most recent 4 hours. It just > sits there > and runs, and I glance at it many times per day in passing. It gets very > messy much > of the time. > > A month-long recording could net you quite a bit of couch time :-) > > Dana > > >> On Sat, Mar 27, 2021 at 11:21 AM Ole Petter Rønningen >> wrote: >> >> Active HM, yes - nothing in the logs that corresponds, except a .5 degC >> diurnal temperature change - which roughly coincides with the outdoor temp, >> so no help there.. >> >> This was meant as a quick-and-dirty check, so a months is not in the cards >> - but that second antenna/receiver is climbing on my list of priorities, in >> imminent danger of surpassing «doing nothing on the couch»! :) >> 27. mar. 2021 kl. 16:52 skrev Dana Whitlow : >>> >>> Ole, >>> >>> If you can stand the suspense, a time error recording of a month or more >>> duration >>> would probably be pretty informative (and interesting for us to see). >>> >>> And when you speak of the maser, is that an active hydrogen maser? If >> so, >>> you're >>> a lucky man (unless it's in the process of dying). But there should be >>> scads of >>> diagnostics being logged, which should be enough to enable making a >> fairly >>> good >>> confidence check on it. >>> >>> Dana >>> >>> On Sat, Mar 27, 2021 at 8:33 AM Ole Petter Rønningen < >> opronnin...@gmail.com> wrote: Hi, Dana Thats the peculiar thing - these last 48 hors theres been a pretty clear 24 hour cycle, pointing to temperature as the culprit; but the >> preceeding 48 hours the phase shift did not follow a 24 hour period at all; the wheather has been all over the place, so it is hard to say.. More data needed! As always.. (of course, there is always a possibility that I’ve somehow bungled the data, and the period has been 24 hours all along) This is why I am looking for ballpark figures for the two main suspects; water and temperature. I guess I should bite the bullet and rig up a second receiver/antenna >> so I can take the maser out of the equation.. (and reseal the connectors properly) >> 27. mar. 2021 kl. 14:04 skrev Dana Whitlow : > > Ole, > > You did not mention whether this timing anomaly is periodic or steadily > growing. > That information could be of considerable diagnostic significance. > > Dana > > >> On Sat, Mar 27, 2021 at 6:08 AM Ole Petter Ronningen < opronnin...@gmail.com> >> wrote: >> >> Hi, All >> >> I am trying to chase down a 2-3-4 ns/day "anomaly" in a gpsdo I am working >> on - it could be temperature sensitivity in the antenna (cheap patch >> jobbie), or I suspect my sealing of the outside connectors may not be >> watertight. I just wanted to ask the list of anyone know of/has an estimate >> of how much the propagation delay on an N and/or SMA can reasonably be >> expected to change in the presence of water? is 3 ns in the right ballpark, >> or would that effect be way bigger/smaller? >> >> Likewise, does anyone have reasonably accurate figures for how much >> temperature could be expected to affect the delay of signals? 20 ps? >> 20 ns? >> Looking for some rough figures so I can look in the right direction.. >> >> I've used the same gpsdo, cable and location with a high quality >> antenna >> without seeing these effects, so I am fairly certain it is the antenna (or >> my reference maser giving up the ghost..) >> >> Thanks! >> Ole >> ___ >> time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send >> an email to time-nuts-le...@lists.febo.com >> To unsubscribe, go to and follow the instructions there. >> > ___ > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com > To unsubscribe, go to and follow the instructions there. _
[time-nuts] Re: Water in connectors
My own belief is that almost everything can be blamed on GPS, but then much if not most is my own fault for using an indoor antenna only about 6 or 7 feet above ground level. Except when excessive lightning activity is around, I run a continuous setup comparing 10 MHz phase between a T'Bolt GPSDO and a Rb, showing I & Q waveforms on a very slow roll-mode 'scope display which shows the most recent 4 hours. It just sits there and runs, and I glance at it many times per day in passing. It gets very messy much of the time. A month-long recording could net you quite a bit of couch time :-) Dana On Sat, Mar 27, 2021 at 11:21 AM Ole Petter Rønningen wrote: > Active HM, yes - nothing in the logs that corresponds, except a .5 degC > diurnal temperature change - which roughly coincides with the outdoor temp, > so no help there.. > > This was meant as a quick-and-dirty check, so a months is not in the cards > - but that second antenna/receiver is climbing on my list of priorities, in > imminent danger of surpassing «doing nothing on the couch»! :) > > > 27. mar. 2021 kl. 16:52 skrev Dana Whitlow : > > > > Ole, > > > > If you can stand the suspense, a time error recording of a month or more > > duration > > would probably be pretty informative (and interesting for us to see). > > > > And when you speak of the maser, is that an active hydrogen maser? If > so, > > you're > > a lucky man (unless it's in the process of dying). But there should be > > scads of > > diagnostics being logged, which should be enough to enable making a > fairly > > good > > confidence check on it. > > > > Dana > > > > > >> On Sat, Mar 27, 2021 at 8:33 AM Ole Petter Rønningen < > opronnin...@gmail.com> > >> wrote: > >> > >> Hi, Dana > >> > >> Thats the peculiar thing - these last 48 hors theres been a pretty clear > >> 24 hour cycle, pointing to temperature as the culprit; but the > preceeding > >> 48 hours the phase shift did not follow a 24 hour period at all; the > >> wheather has been all over the place, so it is hard to say.. More data > >> needed! As always.. > >> > >> (of course, there is always a possibility that I’ve somehow bungled the > >> data, and the period has been 24 hours all along) > >> > >> This is why I am looking for ballpark figures for the two main suspects; > >> water and temperature. > >> > >> I guess I should bite the bullet and rig up a second receiver/antenna > so I > >> can take the maser out of the equation.. (and reseal the connectors > >> properly) > >> > >> > 27. mar. 2021 kl. 14:04 skrev Dana Whitlow : > >>> > >>> Ole, > >>> > >>> You did not mention whether this timing anomaly is periodic or steadily > >>> growing. > >>> That information could be of considerable diagnostic significance. > >>> > >>> Dana > >>> > >>> > On Sat, Mar 27, 2021 at 6:08 AM Ole Petter Ronningen < > >> opronnin...@gmail.com> > wrote: > > Hi, All > > I am trying to chase down a 2-3-4 ns/day "anomaly" in a gpsdo I am > >> working > on - it could be temperature sensitivity in the antenna (cheap patch > jobbie), or I suspect my sealing of the outside connectors may not be > watertight. I just wanted to ask the list of anyone know of/has an > >> estimate > of how much the propagation delay on an N and/or SMA can reasonably be > expected to change in the presence of water? is 3 ns in the right > >> ballpark, > or would that effect be way bigger/smaller? > > Likewise, does anyone have reasonably accurate figures for how much > temperature could be expected to affect the delay of signals? 20 ps? > 20 > >> ns? > Looking for some rough figures so I can look in the right direction.. > > I've used the same gpsdo, cable and location with a high quality > antenna > without seeing these effects, so I am fairly certain it is the antenna > >> (or > my reference maser giving up the ghost..) > > Thanks! > Ole > ___ > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe > >> send > an email to time-nuts-le...@lists.febo.com > To unsubscribe, go to and follow the instructions there. > > >>> ___ > >>> time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe > >> send an email to time-nuts-le...@lists.febo.com > >>> To unsubscribe, go to and follow the instructions there. > >> ___ > >> time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe > send > >> an email to time-nuts-le...@lists.febo.com > >> To unsubscribe, go to and follow the instructions there. > > ___ > > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe > send an email to time-nuts-le...@lists.febo.com > > To unsubscribe, go to and follow the instructions there. > __
[time-nuts] Re: Water in connectors
Active HM, yes - nothing in the logs that corresponds, except a .5 degC diurnal temperature change - which roughly coincides with the outdoor temp, so no help there.. This was meant as a quick-and-dirty check, so a months is not in the cards - but that second antenna/receiver is climbing on my list of priorities, in imminent danger of surpassing «doing nothing on the couch»! :) > 27. mar. 2021 kl. 16:52 skrev Dana Whitlow : > > Ole, > > If you can stand the suspense, a time error recording of a month or more > duration > would probably be pretty informative (and interesting for us to see). > > And when you speak of the maser, is that an active hydrogen maser? If so, > you're > a lucky man (unless it's in the process of dying). But there should be > scads of > diagnostics being logged, which should be enough to enable making a fairly > good > confidence check on it. > > Dana > > >> On Sat, Mar 27, 2021 at 8:33 AM Ole Petter Rønningen >> wrote: >> >> Hi, Dana >> >> Thats the peculiar thing - these last 48 hors theres been a pretty clear >> 24 hour cycle, pointing to temperature as the culprit; but the preceeding >> 48 hours the phase shift did not follow a 24 hour period at all; the >> wheather has been all over the place, so it is hard to say.. More data >> needed! As always.. >> >> (of course, there is always a possibility that I’ve somehow bungled the >> data, and the period has been 24 hours all along) >> >> This is why I am looking for ballpark figures for the two main suspects; >> water and temperature. >> >> I guess I should bite the bullet and rig up a second receiver/antenna so I >> can take the maser out of the equation.. (and reseal the connectors >> properly) >> >> 27. mar. 2021 kl. 14:04 skrev Dana Whitlow : >>> >>> Ole, >>> >>> You did not mention whether this timing anomaly is periodic or steadily >>> growing. >>> That information could be of considerable diagnostic significance. >>> >>> Dana >>> >>> On Sat, Mar 27, 2021 at 6:08 AM Ole Petter Ronningen < >> opronnin...@gmail.com> wrote: Hi, All I am trying to chase down a 2-3-4 ns/day "anomaly" in a gpsdo I am >> working on - it could be temperature sensitivity in the antenna (cheap patch jobbie), or I suspect my sealing of the outside connectors may not be watertight. I just wanted to ask the list of anyone know of/has an >> estimate of how much the propagation delay on an N and/or SMA can reasonably be expected to change in the presence of water? is 3 ns in the right >> ballpark, or would that effect be way bigger/smaller? Likewise, does anyone have reasonably accurate figures for how much temperature could be expected to affect the delay of signals? 20 ps? 20 >> ns? Looking for some rough figures so I can look in the right direction.. I've used the same gpsdo, cable and location with a high quality antenna without seeing these effects, so I am fairly certain it is the antenna >> (or my reference maser giving up the ghost..) Thanks! Ole ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe >> send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there. >>> ___ >>> time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe >> send an email to time-nuts-le...@lists.febo.com >>> To unsubscribe, go to and follow the instructions there. >> ___ >> time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send >> an email to time-nuts-le...@lists.febo.com >> To unsubscribe, go to and follow the instructions there. > ___ > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an > email to time-nuts-le...@lists.febo.com > To unsubscribe, go to and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: Water in connectors
Ole, If you can stand the suspense, a time error recording of a month or more duration would probably be pretty informative (and interesting for us to see). And when you speak of the maser, is that an active hydrogen maser? If so, you're a lucky man (unless it's in the process of dying). But there should be scads of diagnostics being logged, which should be enough to enable making a fairly good confidence check on it. Dana On Sat, Mar 27, 2021 at 8:33 AM Ole Petter Rønningen wrote: > Hi, Dana > > Thats the peculiar thing - these last 48 hors theres been a pretty clear > 24 hour cycle, pointing to temperature as the culprit; but the preceeding > 48 hours the phase shift did not follow a 24 hour period at all; the > wheather has been all over the place, so it is hard to say.. More data > needed! As always.. > > (of course, there is always a possibility that I’ve somehow bungled the > data, and the period has been 24 hours all along) > > This is why I am looking for ballpark figures for the two main suspects; > water and temperature. > > I guess I should bite the bullet and rig up a second receiver/antenna so I > can take the maser out of the equation.. (and reseal the connectors > properly) > > > > 27. mar. 2021 kl. 14:04 skrev Dana Whitlow : > > > > Ole, > > > > You did not mention whether this timing anomaly is periodic or steadily > > growing. > > That information could be of considerable diagnostic significance. > > > > Dana > > > > > >> On Sat, Mar 27, 2021 at 6:08 AM Ole Petter Ronningen < > opronnin...@gmail.com> > >> wrote: > >> > >> Hi, All > >> > >> I am trying to chase down a 2-3-4 ns/day "anomaly" in a gpsdo I am > working > >> on - it could be temperature sensitivity in the antenna (cheap patch > >> jobbie), or I suspect my sealing of the outside connectors may not be > >> watertight. I just wanted to ask the list of anyone know of/has an > estimate > >> of how much the propagation delay on an N and/or SMA can reasonably be > >> expected to change in the presence of water? is 3 ns in the right > ballpark, > >> or would that effect be way bigger/smaller? > >> > >> Likewise, does anyone have reasonably accurate figures for how much > >> temperature could be expected to affect the delay of signals? 20 ps? 20 > ns? > >> Looking for some rough figures so I can look in the right direction.. > >> > >> I've used the same gpsdo, cable and location with a high quality antenna > >> without seeing these effects, so I am fairly certain it is the antenna > (or > >> my reference maser giving up the ghost..) > >> > >> Thanks! > >> Ole > >> ___ > >> time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe > send > >> an email to time-nuts-le...@lists.febo.com > >> To unsubscribe, go to and follow the instructions there. > >> > > ___ > > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe > send an email to time-nuts-le...@lists.febo.com > > To unsubscribe, go to and follow the instructions there. > ___ > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send > an email to time-nuts-le...@lists.febo.com > To unsubscribe, go to and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: Water in connectors
Hi On most “stuff” a humidity to condensation issue shows up as an abrupt change. Temperature hits a critical zone and the water comes out fairly quickly ( or dries off fairly quickly). Net result is that the curve is not as smooth as a normal temperature curve. Bob > On Mar 27, 2021, at 9:32 AM, Ole Petter Rønningen > wrote: > > Hi, Dana > > Thats the peculiar thing - these last 48 hors theres been a pretty clear 24 > hour cycle, pointing to temperature as the culprit; but the preceeding 48 > hours the phase shift did not follow a 24 hour period at all; the wheather > has been all over the place, so it is hard to say.. More data needed! As > always.. > > (of course, there is always a possibility that I’ve somehow bungled the data, > and the period has been 24 hours all along) > > This is why I am looking for ballpark figures for the two main suspects; > water and temperature. > > I guess I should bite the bullet and rig up a second receiver/antenna so I > can take the maser out of the equation.. (and reseal the connectors properly) > > >> 27. mar. 2021 kl. 14:04 skrev Dana Whitlow : >> >> Ole, >> >> You did not mention whether this timing anomaly is periodic or steadily >> growing. >> That information could be of considerable diagnostic significance. >> >> Dana >> >> >>> On Sat, Mar 27, 2021 at 6:08 AM Ole Petter Ronningen >>> wrote: >>> >>> Hi, All >>> >>> I am trying to chase down a 2-3-4 ns/day "anomaly" in a gpsdo I am working >>> on - it could be temperature sensitivity in the antenna (cheap patch >>> jobbie), or I suspect my sealing of the outside connectors may not be >>> watertight. I just wanted to ask the list of anyone know of/has an estimate >>> of how much the propagation delay on an N and/or SMA can reasonably be >>> expected to change in the presence of water? is 3 ns in the right ballpark, >>> or would that effect be way bigger/smaller? >>> >>> Likewise, does anyone have reasonably accurate figures for how much >>> temperature could be expected to affect the delay of signals? 20 ps? 20 ns? >>> Looking for some rough figures so I can look in the right direction.. >>> >>> I've used the same gpsdo, cable and location with a high quality antenna >>> without seeing these effects, so I am fairly certain it is the antenna (or >>> my reference maser giving up the ghost..) >>> >>> Thanks! >>> Ole >>> ___ >>> time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send >>> an email to time-nuts-le...@lists.febo.com >>> To unsubscribe, go to and follow the instructions there. >>> >> ___ >> time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an >> email to time-nuts-le...@lists.febo.com >> To unsubscribe, go to and follow the instructions there. > ___ > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an > email to time-nuts-le...@lists.febo.com > To unsubscribe, go to and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: Water in connectors
Hi, Dana Thats the peculiar thing - these last 48 hors theres been a pretty clear 24 hour cycle, pointing to temperature as the culprit; but the preceeding 48 hours the phase shift did not follow a 24 hour period at all; the wheather has been all over the place, so it is hard to say.. More data needed! As always.. (of course, there is always a possibility that I’ve somehow bungled the data, and the period has been 24 hours all along) This is why I am looking for ballpark figures for the two main suspects; water and temperature. I guess I should bite the bullet and rig up a second receiver/antenna so I can take the maser out of the equation.. (and reseal the connectors properly) > 27. mar. 2021 kl. 14:04 skrev Dana Whitlow : > > Ole, > > You did not mention whether this timing anomaly is periodic or steadily > growing. > That information could be of considerable diagnostic significance. > > Dana > > >> On Sat, Mar 27, 2021 at 6:08 AM Ole Petter Ronningen >> wrote: >> >> Hi, All >> >> I am trying to chase down a 2-3-4 ns/day "anomaly" in a gpsdo I am working >> on - it could be temperature sensitivity in the antenna (cheap patch >> jobbie), or I suspect my sealing of the outside connectors may not be >> watertight. I just wanted to ask the list of anyone know of/has an estimate >> of how much the propagation delay on an N and/or SMA can reasonably be >> expected to change in the presence of water? is 3 ns in the right ballpark, >> or would that effect be way bigger/smaller? >> >> Likewise, does anyone have reasonably accurate figures for how much >> temperature could be expected to affect the delay of signals? 20 ps? 20 ns? >> Looking for some rough figures so I can look in the right direction.. >> >> I've used the same gpsdo, cable and location with a high quality antenna >> without seeing these effects, so I am fairly certain it is the antenna (or >> my reference maser giving up the ghost..) >> >> Thanks! >> Ole >> ___ >> time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send >> an email to time-nuts-le...@lists.febo.com >> To unsubscribe, go to and follow the instructions there. >> > ___ > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an > email to time-nuts-le...@lists.febo.com > To unsubscribe, go to and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: Water in connectors
Ole, You did not mention whether this timing anomaly is periodic or steadily growing. That information could be of considerable diagnostic significance. Dana On Sat, Mar 27, 2021 at 6:08 AM Ole Petter Ronningen wrote: > Hi, All > > I am trying to chase down a 2-3-4 ns/day "anomaly" in a gpsdo I am working > on - it could be temperature sensitivity in the antenna (cheap patch > jobbie), or I suspect my sealing of the outside connectors may not be > watertight. I just wanted to ask the list of anyone know of/has an estimate > of how much the propagation delay on an N and/or SMA can reasonably be > expected to change in the presence of water? is 3 ns in the right ballpark, > or would that effect be way bigger/smaller? > > Likewise, does anyone have reasonably accurate figures for how much > temperature could be expected to affect the delay of signals? 20 ps? 20 ns? > Looking for some rough figures so I can look in the right direction.. > > I've used the same gpsdo, cable and location with a high quality antenna > without seeing these effects, so I am fairly certain it is the antenna (or > my reference maser giving up the ghost..) > > Thanks! > Ole > ___ > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send > an email to time-nuts-le...@lists.febo.com > To unsubscribe, go to and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: Water in connectors
Ole Petter Ronningen writes: > I am trying to chase down a 2-3-4 ns/day "anomaly" in a gpsdo I am working > on - it could be temperature sensitivity in the antenna (cheap patch > jobbie), [...] My first suspect would be temperature-sensitivity of the antenna & preamp. -- 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@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
