[time-nuts] ensemble oscillators for better stability
info at blackmountainforge.com
Sun Dec 30 04:40:09 UTC 2012
I know that this is not germane but I keep thinking of this video:
32 mechanical metronomes on a moveable floor. They all sync up in a bit more
than two minutes.
> -----Original Message-----
> From: time-nuts-bounces at febo.com
> [mailto:time-nuts-bounces at febo.com] On Behalf Of Tom Van Baak
> Sent: Saturday, December 29, 2012 20:17
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] ensemble oscillators for better stability
> >> 1) This was a topic some years back -- for internal use, hp tightly
> >> combined multiple 10811 oscillators so that the net
> phase noise or
> >> short-term performance was significantly better than
> any one of the
> >> constituent oscillators.
> > Care to share a reference on that? It would be interesting
> to see how
> > they did it and how well they where doing it.
> Yes, it came up in a long thread called "GPS noise reduction"
> back in April 2008. I'll mention it again -- when I visited
> the HP facility in Santa Clara years ago I saw or was told
> about a special low noise 10 MHz reference that was used to
> measure the phase noise of shipping 10811 oscillators. The
> reference itself was a set of several hand-picked 10811's
> that were combined in some clever way so that they all
> steered themselves creating a coherent single output with
> significantly lower noise than any one individual 10811. I
> don't have further details but assume the RF and PLL experts
> here on the list can figure out what is meant by this and
> propose a paper design. It was probably more than 2
> oscillators, but I don't remember now if it was 3 or 6 or
> more. Rick Karlquist may also know about this system; either
> when/how it was built or what level of performance it delivered.
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> and follow the instructions there.
More information about the time-nuts