[time-nuts] OT: leaching was, Alternative time interval interpolation technique

Bruce Griffiths bruce.griffiths at xtra.co.nz
Mon Aug 16 20:11:15 UTC 2010

The TDEV plot for the OCXO in question which can be derived from its 
ADEV plot is perhaps a useful guide to the expected jitter when 
measuring a particular time interval.
For long time intervals the phase noise much closer to the carrier than 
5Hz will tend to dominate.


Bob Camp wrote:
> Hi
> Single cycle jitter is a bit confusing when you talk about bandwidths of 5Hz
> to 20 MHz off a carrier. Since phase noise at 5 Hz does contribute to jitter
> over that bandwidth, an OCXO (with good phase noise close in) would be
> needed.
> Bob
> -----Original Message-----
> From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
> Behalf Of Attila Kinali
> Sent: Monday, August 16, 2010 11:53 AM
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] OT: leaching was, Alternative time interval
> interpolation technique
> On Mon, 16 Aug 2010 07:58:01 +1200
> Bruce Griffiths<bruce.griffiths at xtra.co.nz>  wrote:
>> Such low jitter oscillators are readily available.
>> With some care (bandpass filtering) a cycle to cycle jitter of around
>> 50fs or so is attainable with a Wenzel OCXO for example.
> Apropos Wenzel: Is there any distributor that sells them in
> single quantities? Or do i have to get them from Wenzel directly?
> And is there any price list available?
>> However the time interval jitter degrades as the time interval increases.
>> Achieving a cycle to cycle jitter of 1ps or so is relatively easy with a
>> 10MHz or 100MHz OCXO having sufficiently low phase noise.
> Why an OXCO? AFAIK the temperature has only an effect on long term
> stability/drift, but doesn't affect short term effects (which cause
> the jitters). Or am i missing something?
> 			Attila Kinali

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