Almost all rubidium standards DO specify the use of some form of a heat sink. For the FRK and M100 units this can be a heat sink with around 1" fins or just bolted to a metal plate or chassis.
The military freq standard that had M100's in them had the unit mounted to a 5x5x.2" aluminum plate that was in turn bolted to the chassis. My Efratom PTB-100 time bases for the Tektronix TM500 mainframes have a large heat sink mounted to a FRK style oscillator. LPROs are supposed to be mounted to a metal chassis (they usually come with a thermal pad attached to them). I have seen them lose lock in free air. I saw one mounted in a piece of cell phone equipment. It was bolted to a large heat sink that formed most of the front of the enclosure. I have also seen FE-5680A's in their native habitat (again, cell phone equipment). They were mounted to a thick (1/8"?) PCB around 6x16". The side of the PCB that the 5680 was bolted to had a solid ground plane. The 5650A's had one side bolted to a metal chassis. ---------------------------------------- _________________________________________________________________ Hotmail® has ever-growing storage! Don’t worry about storage limits. http://windowslive.com/Tutorial/Hotmail/Storage?ocid=TXT_TAGLM_WL_HM_Tutorial_Storage_062009 _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
