[time-nuts] Rapid startup GPSDO

[Murray Greenman]

Jim,
Would an inexpensive Rubidium unit do what you want? I know it won't be
closer than a few ppb, but in my experience (LPR101, FE-5650A, FE-5680A)
they are stable inside about four minutes. The big advantage is they
don't need GPS at all.

Regards,
Murray ZL1BPU



Message: 1
Date: Wed, 14 Jul 2010 06:42:50 -0700
From: jimlux <jimlux at earthlink.net>
Subject: [time-nuts] rapid startup GPSDO
To: Discussion of precise time and frequency measurement
	<time-nuts at febo.com>
Message-ID: <4C3DBEDA.7010304 at earthlink.net>
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Is there some (inexpensive) GPSDO that has a "time from power on in an 
unknown location to reasonably stable" in the <5 minute category?

Frequency accuracy in the 1E-9 range would be fine.

A regular old GPS has a Time to First Fix well under that, and it should

be cranking out 1pps pulses with 1E-7 or 1E-8  precision pretty 
quickly.. Would it be fair to say that after 100 seconds, one could 
theoretically have driven that down another factor of 10?

As I understand it, a thunderbolt needs some number of hours after turn 
on to stabilize, but just how bad is it after, say, 5 minutes.