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Re: [Discuss-gnuradio] USRP2 phase drift
From: |
Marcus D. Leech |
Subject: |
Re: [Discuss-gnuradio] USRP2 phase drift |
Date: |
Mon, 26 Jul 2010 17:54:07 -0400 |
User-agent: |
Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1.11) Gecko/20100720 Fedora/3.0.6-1.fc12 Thunderbird/3.0.6 |
On 07/26/2010 04:00 PM, Matt Ettus wrote:
>
> Even if you lock the USRP2 to an external reference, there will still
> be drift relative to other things not connected to the same
> reference. The function generator has its own clock, as does GPS.
>
> Matt
>
>
Somewhat disturbingly, I've also observed in the lab phase-hits between
two GPS receivers, being fed from
the same antenna! I suspect differences in the phase locking
algorithms or something. But you can't
even rely on GPS to be consistent with itself (at least viewed by two
different GPS receivers!!).
--
Marcus Leech
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
http://www.sbrac.org