Re: Quick and dirty GPSDO build by F2DC and me.
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talks about potential problems with a 1PPS reference in GPSDO (GPS Disciplined Oscillator) circuits.? If using 1PPS to stabilize an oscillator
it seems that the best short-term accuracy might be + or - 1/2 Hz, unless one
uses some more analog like technique to add or subtract phase shift to get
sub-1Hz stability.? Several of the popular GPSDO circuits look more like the
H&P (Huff and Puff) circuits that were popular a few years ago.
I am not an expert at GPS disciplined objects.? Others may have better
answers.
Arv _._
On Tue, Jun 22, 2021 at 3:26 PM Sverre Holm < svholm54@...> wrote: I downloaded the PD0EK version of the F2DC software and have had it running for a while. I'm using it with the QLG-1 GPS from QRPLabs. What I find is that the measurement gate with time goes from ... 4, 8, 16, 32, 64, 128, 256, 400 seconds, but the measurement error never stabilizes, but shows -6, 28, and seldom 0 i.e. and therefore it is rare that the display shows "lock".
Is this normal? Or could I have a jitter problem in the 1 PPS pulse from the GPS?
Sverre
LA3ZA
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