In message <[EMAIL PROTECTED]>, "Matt Ettus" writes: >Since we can now make DDS's with arbitrary frequency resolution, could >you make an Rb oscillator without the magnetic field adjustment? >Wouldn't that reduce a source of error in frequency? Then we'd be >left with the ideal resonance frequency, right? > >Are there any other influences on the resonance frequency? I assume >temperature and density don't matter.
In fact density/pressure does matter and is one of the major reasons why rubidiums drift: Rubidium is absorbed into the glas container and as the pressure drops the frequency pulls. The absorption also makes the glas darker and darker, being a major wear-out mechanism for Rb units. As far as I know, this is why Rb is never classified as a primary standard: A drift-free unit has yet to be constructed. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. _______________________________________________ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
