[time-nuts] GPS discipline oscillator vs phase lock

Bob kb8tq kb8tq at n1k.org
Fri Jun 16 17:46:45 EDT 2017


Hi

A far more common approach is to let the two oscillators free run and to record something like a local broadcast station. 
You then post process all of the data to give you the phase accuracy. One of several gotcha’s is the stability of any 
radio link at the level you are looking for.

Bob

> On Jun 16, 2017, at 5:01 PM, life speed <life_speed at yahoo.com> wrote:
> 
> I was afraid of that, I guess it doesn't hurt to ask.  Perhaps I could implement an ISM band radio link for the purpose of locking the two oscillators.  Of course that wouldn't reach a couple miles either.
>  
> - Lifespeed
> 
> 
> 
> Hi
> 
> A *lot* depends on your definition of “phase locked”.  If indeed you are after 0.1 degree at 100 MHz, that gets into the “no can do” range. To put some numbers on it, 0.1 degree at 100 MHz is 2.7 ps. GPS time as received simply is not stable to that level … If you drop back to about 20 degrees, you start to get into the “maybe can do” range. 
> 
> Bob
> 
> 



More information about the time-nuts mailing list