[time-nuts] New topics (was Re: He is aTime-Nut Troublemaker....)

[Chuck Harris]

Hi Didier,

I presumed you at one time knew the difference between voltage
ratio, and power ratio dB, but your question gave the impression
that you might have needed a tiny nudge to refresh your memory.

If both oscillators are in lock step, you obviously can combine
them using an appropriately wound transformer to gain a 3dB increase
in power.  But it would seem that the noise, being random and
independent, should add constructively as often as destructively.

I don't know the answer to your question... I did once, but that was
30 years ago... but I get the feeling that the noise power is going
to add up as some fractional power giving you a net improvement
in signal to noise... probably close to 3dB, but not quite 3dB...
I just don't remember anymore.

-Chuck Harris

Didier wrote:
> Chuck,
> 
> I am quite familiar with how to calculate a voltage or power ratio in dB,
> but refering to the first issue, when you combine two oscillators, does the
> noise improve by 3dB?
> 
> Didier