[time-nuts] Some observations of the BG7T BL GPSDO (John Miles)
willis.hendley at gmail.com
Thu Mar 26 21:57:25 EDT 2015
[Apologies if I've messed up this reply - my first posting to timenuts as a
> See performance plots, data files, and summary at
> http://www.ke5fx.com/gpscomp.htm . Thanks to Bob, W7AVK for the loan of
> the unit for testing! Would be curious to know if anyone else has
> encountered a similar frequency error, or if the issue I saw was unique to
> this particular example.
In looking through the ublox Timing Appnote on the ublox 6 GPS receivers:
aside from possible sources of error from antenna cable delay and multipath
it also refers to quantization error of the timing pulse itself.
Is it possible that this also has a systematic offset or is this just
contributing to the observed noise level around the mean? Being new to the
concept of GPSDOs I have no idea how much these intrinsic errors in the GPS
receiver itself bleed through to the performance of the output frequency
from the OCXO - or is it all masked by the long time constants and filtering
in the Software PLL loop?
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