[time-nuts] Counter Internal Oscillator Importance with External Reference?

[Magnus Danielson]

Hi Poul-Henning,

On 05/09/2017 02:39 PM, Poul-Henning Kamp wrote:
> --------
> In message <60c74d75-41e5-7112-d8b6-721664b895af at rubidium.dyndns.org>, Magnus Danielson writes:
>
>> Indeed. On the other hand some measurements is hard not to do that way.
>> One should think about how isolation is created if needed, and this
>> includes AC and DC, common mode and differential mode. Isolation
>> amplifier should be part of the arsenal.
>
> EMI is part of it, but there raw synchronism is a significant
> source of systematic errors because the "noise" is no longer
> gaussian.
>

Wither it is proper side bands or other systematic noise, it is bad 
indeed, that would be part of the RF differential mode disturbances.
This assumes the source is "clean", and if it is not it should not be 
used to start with. What remains is really issues from the setup, and 
that's when signal integrity/EMI care and isolation amplifiers comes in.

Cheers,
Magnus