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? 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. 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?? Best Regards Martyn This Email is from: Martyn Smith Precision Test Systems LTD Tel: +44 (0) 1245 329608 Email: martyn@ptsyst.com Web: www.ptsyst.com NOTICE - This message contains legally privileged and confidential information intended only for the use of the addressee named above. If you are not the intended recipient of this message, you are hereby notified that you must not disseminate, distribute, copy or take any action in reliance on it. If you have received this message in error, please notify Precision Test Systems LTD. This communication represents the originator's personal views and opinions, which do not necessarily reflect those of Precision Test Systems Ltd. from whom it emanates. Further, Precision Test Systems Ltd. will not be held responsible for its contents and/or attachments, if the communication contravenes the rules of Precision Test Systems Ltd's email policy.

> 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? Martyn, I thought almost all GPSDO derive their 1PPS output from the OCXO and thus phase coherence between the 10 MHz output and the 1PPS output is guaranteed by design, no? If your GPSDO doesn't do this, how are you locking your OCXO to the GPS receiver 1PPS? /tvb

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