I wonder what the detailed thermal model of telecom Rb's looks like. I cool my PRS-10's hear sink surface to ~55C with a heatsink, but parts of some other surfaces of the package run several degrees hotter. This rather puzzles me, and worries me.
Dana On Tue, Oct 5, 2021 at 10:46 AM Bob kb8tq <kb...@n1k.org> wrote: > Hi > > Rubidiums are somewhat unusual beasts. They typically have two heated > zones ( = two ovens) in > them. One is a bit hotter than the other. Because of the basic physics, > those ovens are right next > to each other / in contact with each other. > > If you go to crazy with the insulation, the “colder” oven will heat up due > to heat leakage from the > “hotter” oven. You need a certain amount of heat coming off the package > to allow this to happen. > > The bigger issue is that there is a pretty big batch of electronics near > the ovens in the typical telecom > Rb. Unless you heatsink things pretty well these parts heat up. When they > do their MTBF drops > quite a bit. You save a couple of watts of heat (maybe) and loose the Rb > after a year or two. Not > a great tradeoff. > > Yes, there are a lot of different designs for lab grade Rb’s. There are > also some really tiny little > guys running around. Neither category is all that easy to get on the > surplus market. If you want > to dive into either of those categories, there are issues, they just may > not be quite the same. > > Bob > > > On Oct 4, 2021, at 1:39 PM, Wim Peeters <peeter...@scarlet.be> wrote: > > > > Insulation decreases the power consumption. But it will also increase > the temperature of the electronics. > > > > A heath-sink will cool the electronics but will increase the power > consumption. > > > > Or maybe insulate the part of the case that gets hot, and put a > heat-sink on the other parts? > > > > Wim Peeters > > _______________________________________________ > > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe > send an email to time-nuts-le...@lists.febo.com > > To unsubscribe, go to and follow the instructions there. > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send > an email to time-nuts-le...@lists.febo.com > To unsubscribe, go to and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.