[time-nuts] PRS-1- Rubidium

[Chuck Harris]

All epoxy dipped tantalum capacitors are dry electrolytic tantalum
capacitors.

Dry electrolytic tantalum capacitors have no electrolyte.  That is
why they are called dry.

In manufacture, a sintered tantalum slug is etched so that its surface
is full of lots of nooks and crannies.  A microscopically thin solid
dielectric coating is applied to the slug, and then a coating of a
conductive metal is applied over the dielectric.

The slug is one electrode, and the conductive metal coating is the
other electrode, and the dry dielectric coating is the dielectric.

There is nothing in a dry electrolytic tantalum capacitor to cause
corrosion.  However, burned epoxy circuit board is very corrosive.

-Chuck Harris

Bruce Hunter via time-nuts wrote:
> Jurg,
>
> I did not see your picture before responding earlier.  Check the dipped tantalum
> on the right for a hole that spouted acid.  The device on pillars is a preliminary
> heating resistor for the rubidium bulb.  Be sure to measure its spacing from the
> bulb, if you are going to remove the circuit board, as this is critical to the
> warm up cycle.
>
> Bruce, KG6OJI