Really?? The circuitry employed is something of a joke surely?
Relying on the MOSFET characteristics to limit warm up current is unwise. The temperature sensor also would appear to suffer from large variations in output from one part to another. Bruce > > On 05 June 2017 at 01:21 "R. Kuehn" <reku...@gmail.com> wrote: > > Maybe you want to check out the work of Hans Summers he has done some > impressive low cost stuff: > http://www.hanssummers.com/ocxosynth.html > http://www.qrp-labs.com/ocxokit.html > > Ralph > > On Sun, Jun 4, 2017 at 07:19 jimlux <jim...@earthlink.net> wrote: > > > > > > I recall some years ago folks were talking about putting a PTC > > thermistor on the TCXO of a FlexRadio SDR1000 to stabilize the > > frequency > > as a sort of poor-man's OCXO. > > It's also referenced at > > http://www.setileague.org/askdr/xtaloven.htm > > where he says "order of magnitude improvement" with no numbers > > (from 1% > > to 0.1% or from 1 ppb to 0.1 ppb?) > > > > I wonder how well that actually works. > > > > Say you bought an inexpensive (perhaps non TC) XO and an equally > > inexpensive thermistor, glued on on the other, hooked em both up to > > 3.3 > > or 5V. > > > > Yeah, there's issues with room air blowing on it, and tolerances in > > both > > the XO and thermistor, so your absolute frequency accuracy may not > > be so > > hot. But what sort of medium to long term performance can one > > expect. > > > > I did some searches, because I'm sure we've discussed this before, > > but I > > couldn't find it. There was some stuff from Oct 2007, but that was > > in > > the context of a more complex circuit, and the thermistor was the > > sensor. (discussions of TE devices 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.
