[time-nuts] temperature stability basics

[Rick Karlquist]

FWIW:

During the development of the E1938A, we tried replacing
the foam insulation with a skeleton plastic frame with knife
edges.  The idea was that the plastic would have negligible
heat conduction, leaving only air convection and radiation.
We didn't see much difference between this set up and the
regular foam, in terms of heater power.  It also didn't make
much difference with thermal gain.

Also, with both this oscillator and the 10811, different
kinds of foam were tried.  The general consensus was that
all foams were more or less similar thermally, and the
important characteristics differentiating them were mechanical
(ability to not maintain shape after long exposure to oven
temperatures) and various other manufacturing, supply chain,
regulatory and environmental issues.

Rick Karlquist
N6RK