[time-nuts] LPRO Rubidium schematics
warrensjmail-one at yahoo.com
Wed Jun 1 15:48:31 UTC 2011
LPRO time nuts,
Is there a complete set of schematics available for the Efratom LPRO-101 Rubidium oscillator?
I have the "Repair reference guide by Fred de Vries, PE1FBO, Revision 6, 2010" which is very useful, but unfortunately it includes only some of the schematics.
What I'm looking for is a schematic of the 20 MHz osc section and it's control loop.
In an ongoing effort to initially see how good, and ultimately how simple, I can improve the performance of a LPRO based oscillator system,
I've started with the basics by using a low noise 10811 as a clean up osc to improve the under 100 sec noise.
To minimize any room temperature swings from effecting the performance, I've added an active temperature controller to keep the base plate heat sink temperature constant.
To remove long term daily drift and get absolute freq accuracy, I'm using the C-field to discipline it to GPS.
For that I'm using the LPRO as the external oscillator for a Tbolt and set the Tbolt's extended time constant at 12 to 24 hrs using Lady Heather.
The results to date are very encouraging and show substantial improvement over the whole tau range from 0.01 sec out to days, in effect providing a low cost Cs substitute.
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