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 <[email protected]>: > > 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 <[email protected]> >> 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 <[email protected]>: >>> >>> 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 < >> [email protected]> >>>> 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 <[email protected]>: >>>>> >>>>> 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 < >>>> [email protected]> >>>>>> 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 -- [email protected] -- To unsubscribe >>>> send >>>>>> an email to [email protected] >>>>>> To unsubscribe, go to and follow the instructions there. >>>>>> >>>>> _______________________________________________ >>>>> time-nuts mailing list -- [email protected] -- To unsubscribe >>>> send an email to [email protected] >>>>> To unsubscribe, go to and follow the instructions there. >>>> _______________________________________________ >>>> time-nuts mailing list -- [email protected] -- To unsubscribe >> send >>>> an email to [email protected] >>>> To unsubscribe, go to and follow the instructions there. >>> _______________________________________________ >>> time-nuts mailing list -- [email protected] -- To unsubscribe >> send an email to [email protected] >>> To unsubscribe, go to and follow the instructions there. >> _______________________________________________ >> time-nuts mailing list -- [email protected] -- To unsubscribe send >> an email to [email protected] >> To unsubscribe, go to and follow the instructions there. > _______________________________________________ > time-nuts mailing list -- [email protected] -- To unsubscribe send an > email to [email protected] > To unsubscribe, go to and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] -- To unsubscribe send an email to [email protected] To unsubscribe, go to and follow the instructions there.
