Dear Andy, LF Group,
Thanks for writing about this very interesting project -
At 15:17 28/01/2002 +0000, you wrote:
The effect is to keep the VCXO precisely locked in the long term to the GPS
signal, although in the short term it's instantaneous phase is jittering,
and therefore the frequency is shifting by a Hz or two every second. By
apropriate choice of charge pump R/C values, the jitter can be minimised.
When this source is subsequently divided down to LF, the phase shift is
reduced by the division factor.
What is the source of the jitter here - is it being introduced by the
stabilisation circuit, or that due to the VCXO itself? Also, I can see that
it would not matter much for long symbol lengths like Jason or you coherent
PSK system, but would the jitter be a problem for something like WOLF, with
it's 10 bits/s?
Cheers, Jim Moritz
73 de M0BMU
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