30 years that is remarkable glad I have such a tube in my 5061B In a message dated 11/2/2016 10:53:50 A.M. Eastern Daylight Time, richard@karlquist.com writes: This has probably been covered here before, but, at least going to the 5071A, now 25 years ago!, all CBT's, whether high performance or not, have the same amount of cesium inside. This means that the standard performance (never call it "low" performance) CBT has enough cesium to last 30 years! Thus for those tubes, we can rule out cesium replenishment even if it were possible. Rick On 11/1/2016 8:38 PM, Mark Sims wrote: > You mean I can't just drill a hole in, wash out the old cesium with some tap water ;-), toss in some new cesium, suck out the air, bung a cork in the hole, and call it a day? Drat! foiled again... > > --------------- > >> Because it's not that easy. We are talking about a high vacuum system here. > _______________________________________________ > 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.