[time-nuts] Re. DIY atomic "resonator"

[Richard (Rick) Karlquist]

On 4/11/2017 12:31 AM, Andre wrote:

> Has anyone else either built an atomic clock around a bare Rb lamp module "core" or attempted
>

Not a DIY project, but I was the RF designer on the HP 10816 rubidium
standard, which never made it to product introduction (a half dozen
working pilot run units were built in 1982).  I would say this task is
probably beyond the scope of a DIY project, at least for most
time-nuts.  The Rb lamp drive circuit (particularly getting the
lamp to light up) is very challenging.  The step recovery diode
multiplier is very challenging.  The photodetector and loop
integrator is non trivial.  The synthesizer is the one thing that
is easy in 2017.  The oven is also no simple thing to get
low tempco.  Unlike a crystal, you have a lot of heat being
generated by the lamp, etc. The lamp needs to be at a different
temperature than the other cells.  You have to keep the tip
off at the lowest temperature to keep the Rb in place and not
"flood" the cell and block the light.  Etc., etc.

This is in the category of projects where if you were qualified
to do it, your time is far too valuable to do it for the amount
of money you would save.

Rick N6RK