Speaking as a process control engineer, it sounds like too much gain. You can verify that it is the oven by warming up the device somehow. That should change the period of oscillation. If it is still 7 minutes then reduce the gain somehow.
You can elevate the temperature of the device by putting it in a large cardboard box with a 60 or 100 watt incandescent light. Monitor the temperature. Regards Bill Hawkins -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Alberto di Bene Sent: Sunday, October 23, 2005 10:30 AM To: Discussion of precise time and frequency measurement Subject: [time-nuts] RE: phase locking Rb to GPS Richard H McCorkle wrote: > [snip] > In interfacing an Isotemp mil spec version of the HP 10811B with a > sensitivity of 9.7e-9/volt and a span of 4.85e-8 to the Shera controller > even with [snip] Richard, do you perhaps have any experience of using the Isotemp OCXO134-12 unit ? I built a GPSDO using it, and it works rather well, were it not for a residual oscillation of the frequency of about +- 2E-11. i.e. +- 0.0002Hz at 10MHz, with an oscillation period of about 7 minutes, which is too fast to be corrected by the PI software loop. I attributed it, lacking other explanations, to an imperfect temperature control of the oven. Translated in temperature terms, that frequency oscillation amounts to a change of about 0.18 degrees Celsius. What you think about this ? TNX 73 Alberto I2PHD _______________________________________________ time-nuts mailing list [email protected] https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts _______________________________________________ time-nuts mailing list [email protected] https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
