Bert, remember that I need a very long locking loop time constant setting in order to smooth out GPS noise, so in a sense the GPSDo is *almost* in a holdover state anyway, all the time.
Probably the smartest thing for me to do is to buy a spanking new PRS-10, with the PPS locking feature present. Then I could just leave it locked to GPS most all the time, but disconnect the PPS and let it go into holdover on the rare occasions when I need a few hours of even better stability. Dana On Tue, Jul 20, 2021 at 6:56 PM ew via time-nuts <time-nuts@lists.febo.com> wrote: > There is a lot of misinformation out there. It is not the OCXO that > changes, Bruce did extensive testing and I did some too. The Vectron is > super, would like to know what is in it but do not want to open one. Once > warmed up the stable OCXO temperature is a main contributor to the board > temperature. Using a Dual Oven may give you a warm feeling but only adds 1 > more Watt of stable heat to the board making the temperature change > smaller. The OCXO is important during Hold Over and that is why it is > there. The changes are the DAC which is updated once a second. Very > temperature sensitive. Cheap. We have done the tests 10811, OSA 8600, FRK > and M100. For fun did use a cheap small OCXO, no performance change. Was > done in Juerg's temperature stable basement. See attached picture. > > Bert Kehren > My experiences with the T'Bolt have not been entirely satisfactory. If I > set the loop > lime constant long enough to get a satisfying smoothing of the GPS noise (a > few hundred > seconds), then the thermal sensitivity of the VCXO on the T'Bolt rears its > ugly head and > I see a lot of my HVAC system cycling instead. The T'Bolt E supposedly has > a double- > oven XO, so I'd like to give that a try. But my wallet says "whoa"! > > According to Bodnar, his units do have some choices in the time constant > setting. > I've been considering ordering a Bodnar just for frequency agility, but > have been > holding off out of concern for the complications of dealing with a foreign > supplier. > > Dana > _______________________________________________ > 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.