It depends on whether the leakage continues to rise or stabilizes after a "burn in" period.
-John ============ > Hi Bob yes that was a point raised by Prof Nat Sokal after I published > some > data, or rather he pointed out it happened in RF amps. I guess if you take > an used PA transistor out of service and measure it you might find the > base > emitter junction very leaky, but does few mA of leakage matter so much in > a > low impedance high drive power circuit. > Reliability asks "does it do the job it was designed for" not "is it as > good > as new now" > > Alan > G3NYK > ----- Original Message ----- > From: "Bob Camp" <li...@rtty.us> > To: "Discussion of precise time and frequency measurement" > <time-nuts@febo.com> > Sent: Sunday, August 15, 2010 1:33 AM > Subject: Re: [time-nuts] Simulation > > >> Hi >> >> Simulation might or might not have helped. >> >> 1) Was Vbe breakdown even included in the Spice model >> 2) If so did it ring bells (rare) or did it just clip without error ( > common ) >> 3) Would the same designer who didn't understand it in the first place > have seen it clipping at -5 and concluded "looks to be in spec at -5" >> 4) Would any of it be reviewed in light of the new transistor or was the > guy on another project by then >> >> My favorite in the absolute max Vbe category is the typical class C RF > amp. Look at the spec, check a few thousand working boards. Scratch head > and > move on. Lots of reverse bias on the base and they run forever. >> >> Bob > > > _______________________________________________ > 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. > > _______________________________________________ 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.