Taking Alan Melia's point that there aren't enough of these devices to establish good statistics and Bob Camp's point that temperature can cause components to fail before the physics package, I'd suggest that there is a need to specify the thermal environment for the 15 year run. How large was the heat sink? Did it have a fan?
Also, the M-100 is the military version of the FRK-L that Collins used in its Omega navigation receivers, which were rated for commercial aircraft, probably with redundancy. Mil-spec parts would be somewhat more reliable than commercial parts. In my experience with industrial process control systems, anyone who needed reliability used redundancy, and hoped that the fail-over software would work. When safety was a concern triple redundancy was used with 2 of 3 voting for output values. FWIW Bill Hawkins -----Original Message----- From: Rob Sherwood. Sent: Sunday, March 27, 2016 11:34 AM My Efratom M-100 has been running for about 15 years 24/7. I have no idea if that is typical. It was purchased as NOS for $300. Rob NC0B _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.