[time-nuts] Determination of the placement of the first pps
Magnus Danielson
magnus at rubidium.dyndns.org
Tue Jan 24 18:50:41 UTC 2012
On 01/24/2012 12:42 PM, J. L. Trantham wrote:
> Thanks Chris.
>
> It seems such a logical feature to have, I would think it would have been
> included perhaps by a serial command. My old CS clocks have this feature
> though I have never taken the time to sync them.
"Jumping" the PPS into about the right phase is done within a second and
is well worth the effort. I use this myself and it works well.
Forcing "sync" on atomic clocks is badly needed. The frequency steering
range is small so frequency limit sideways would take ages.
Cheers,
Magnus
> Joe
>
> -----Original Message-----
> From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
> Behalf Of Chris Albertson
> Sent: Tuesday, January 24, 2012 12:34 AM
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] Determination of the placement of the first pps
>
>
> On Mon, Jan 23, 2012 at 5:50 PM, J. L. Trantham<jltran at att.net> wrote:
>> Is this, in any way, related to the fact the Earth has a Moon?
>>
>> is there a way to
>> 'sync' the 1 PPS output of an FE-5680A to an external signal, such as
>> a GPS receiver or TBolt? I would think that might be possible given
>> their original purpose.
>
> The 1PPS is not in the units specs. It is just by luck that it works.
> However we could adjust the phase of the 1PPS by running the unit fast or
> slow for some period of time and then going back to exact 10MHz. But that
> method could take a LONG time, like tens of thousands
> of seconds. Better I think to test the phase and if it is "off" by
> more than say, 0.01 second to just power the unit off and restart and
> see what luck gives you. I bet 100 power cycles is faster than
> moving the phase by 0.5 seconds.
>
> Maybe the answer is to wire up a few decade divers and divide the 10MHz to
> 1pps yourself. Thenyou can let a known good PPS reset your counters and get
> the phase correct instantly
>
>
>
>
>
>
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