Hi The only issue with the “controlled fan” approach is that you have a variable magnetic field as a result. That and the vibration both can impact the stability of the Rb. Some means of isolating the fan from the immediate vicinity of the Rb sounds like a good idea.
Bob > On Oct 21, 2020, at 9:31 AM, Luiz Alberto Saba <[email protected]> wrote: > > I am thinking in an black aluminium finned heatsink, the size of the base > plate, and a fan, controlled by an electronic thermostat (sensor direct > coupled to the heatsink). Is that ok? > > Em 21/10/2020 09:40, Wannes Sels escreveu: >> There are conflicting requirements regarding temperature in Rb's: >> >> - For best performance, the rubidium and quartz oscillators must be kept at >> a high and stable temperature. >> - For reliability, the supporting electronics must be kept at a lower >> temperature. >> >> The heater takes care of the high temperature. The stability of the >> temperature can be improved by increasing the thermal mass, i.e. adding a >> block of aluminium or copper. >> The electronics can be kept cooler with a heatsink, and forced ventilation >> if needed. >> >> When you stick both the electronics and physics in a small package, this >> becomes more difficult. For the PRS-10 some form of heatsink is pretty much >> required to keep the electronics cool enough. Although I seem to remember >> reading somewhere that the "benchtop" heatsink they offer now is lighter >> than older units. >> >> If the room temperature is not stable enough, you might want to increase >> the size of the heatsink and add a fan. This reduces the temperature swing >> inside the unit, while still cooling the electronics, at the cost of >> increased power draw for the heater. >> >> >> >> >> On Wed, Oct 21, 2020 at 5:38 AM Hal Murray <[email protected]> wrote: >> >>>> I spent a lot of years buying Rb’s and putting them on small heatsinks. >>> I >>>> always was disappointed in their reliability. That continued to be the >>> case >>>> up to the point that the baseplate temp’s got into the 40C region. In my >>>> case, that took a fan …. >>> How well did it work if the heat sink wasn't small? What is your version >>> of >>> small? >>> >>> Do you have any data (or vague memories) of how much it helps to orient >>> the >>> heat sink so the fins are vertical so they encourage warm air to flow up >>> past >>> the fins? >>> >>> -- >>> These are my opinions. I hate spam. >>> >>> >>> >>> >>> _______________________________________________ >>> time-nuts mailing list -- [email protected] >>> To unsubscribe, go to >>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >>> and follow the instructions there. >>> >> _______________________________________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
