Chris wrote on 8/5/2017 2:33 PM:
On 08/05/17 14:48, rickman wrote:


You aren't making sense. The reference is never adjusted in a PLL.
That's why it's the *reference*.

Just where did I say that ?. Having worked with pll's since the
4046 and earlier, I should know the difference.

You snipped the part I was replying to but you talked about the master
knowing the status of the slave which would only be useful if you were
adjusting the master.


In a pll, there is continuous feedback from the vco to the phase
detector, closing the loop and keeping the phase offset constant,
The phase is continuously updated every cycle, whereas the Shortt
clock can have significant accumulated error in the time between
corrections...

There is no requirement in a PLL for continuous action or even frequent
action.


That's probably why the Shortt clock is described as a hit and miss
system and correction is unipolar, whereas a classic pll continually
updates the vco every cycle, not multiples thereof.

"Classic"??? There is no such definition of a PLL to "continuously" update
anything.


Ok, the Shortt clock is probably as close as you can get to a classic
pll using mechanics :-)...

Yes, because it *is* a PLL. In fact the problem most people have with it is
that it doesn't adjust the phase by adjusting the frequency of the slave.
It adjusts the *phase* so clearly it *is* a phase locked loop.

--

Rick C