[time-nuts] A small piece on HP's hydrogen maser in 1968

[Tom Van Baak]

> So what's all this about a Thallium Beam Tube???

For info about the pro/con of Thallium beam frequency standards, see:

http://tf.boulder.nist.gov/general/pdf/9.pdf
http://tf.boulder.nist.gov/general/pdf/211.pdf
http://leapsecond.com/history/1965-Metrologia-v1-n3-Cesium.pdf

Imagine 21310.833946 MHz instead of 9192.631770 MHz...

/tvb