[time-nuts] Determination of the placement of the first pps

J. L. Trantham jltran at att.net
Tue Jan 24 06:42:36 EST 2012

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.


-----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


Chris Albertson
Redondo Beach, California

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