[time-nuts] 10 MHz Phase Coherent

[Magnus Danielson]

From: "Martyn Smith" <martyn at ptsyst.com>
Subject: [time-nuts] 10 MHz Phase Coherent
Date: Fri, 25 May 2007 12:38:21 +0100
Message-ID: <00c801c79ec1$43ae1f70$0301a8c0 at desktop1234>

Martyn,

> My company Precision Test Systems makes GPS Disciplined rubidium and OXCO frequency standards (www.ptsysyt.com).  Well that's my free add!!!  What I am always being asked for is to have the 10 MHz sinewave of a GPSDO in phase with the 1 pps pulse (which is UTC aligned).
> 
> Does anyone know if any companies make units where the 10 MHz is in phase with the 1 pps UTC signal?  

Yes, for instance my company do that. For certain applications, you must have
a 1:10.000.000 relation or else the box is broken and can't be used. My
customers require that, and for a good reason.

> I'm not convinced anyone needs this feature, but customers keep asking for it, then don't realise they will have to be very careful with their cabling to maintain the phase.

For some applications they do require it. Some equipment even require a very
tight phase-relationship between the PPS rising edge and the rising edge at
through zero on the 10 MHz.

> I actually have another product that effectively does this, so I could add it as an option.  But as I said, does anyone really need this??

Yes.

Cheers,
Magnus