Affected Products: Jackson Labs or Symmetricom time/frequency reference boards based on Symmetricom chip scale atomic clock, most common unit is the CSAC GPSDO sold by both symmetricom vendors and direct from Jackson labs Type of issue: Short and Long-term reliability, mfr couldnt assure that if it works for 1week, 1month or 1year it is not an affected unit Issue: CSAC Loss of vacuum, sudden onset failure mode Result: CSAC unable to control the temperature, Indefinite warm-up state, ultimately the unit fails to reach a lock state Failure Rate: Vendor noted ~5% of all units, internally it has been 1 of maybe a dozen or less units to date Resolution Status: Issue acknowledged by manufacturer but not resolved, still affecting all current stock and current production units, Jackson Labs will replace the CSAC part on the board and return without a fee though admittedly the new part may also fail Details: While resolving an issue with a Jackson Labs CSAC GPS Disciplined Oscillator board, we were made aware of a reliability issue affecting all timing boards built around the new Symmetricom Chip Scale Atomic Clocks (a.k.a. CSAC). There is a fundamental design flaw that can result in the loss of vacuum in the CSAC, which prevents the unit from being able to effectively control the parts operating temperature. The end result is a unit that is in an indefinite warm-up state. We were informed that all current and even currently produced units can fail in this way. The number we were given was ~5% of all units will fail, so we happened to get one of those 5%. The failure mode is a very sudden onset failure, for our case one day it worked and the next day (during a test of course) it did not. Also this is not a case of if it works the first week then it will be fine, it can fail anytime (in my case I had used it on a regular basis for several months prior to the failure). Our unit also spent 99% of its life in an air conditioned lab so certainly not subjected to even a remotely harsh environment.
Lester B Veenstra MØYCM K1YCM W8YCM [email protected] US Postal Address: 5 Shrine Club Drive HC84 Box 89C Keyser WV 26726 GPS: 39.336826 N 78.982287 W (Google) GPS: 39.33682 N 78.9823741 W (GPSDO) Telephones: Home: +1-304-289-6057 US cell +1-304-790-9192 UK cell +44-(0)7849-248-749 Guam Cell: +1-671-929-8141 Jamaica: +1-876-456-8898 This e-mail and any documents attached hereto contain confidential or privileged information. The information is intended to be for use only by the individual or entity to whom they are addressed. If you are not the intended recipient or the person responsible for delivering the e-mail to the intended recipient, be aware that any disclosure, copying, distribution or use of the contents of this e-mail or any documents attached hereto is prohibited. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
