[TowerTalk] Vacuum tube 100 years old today

[Jim Lux]

----- Original Message -----
From: "Steve Katz" <stevek at jmr.com>
>
>
> > "For many applications a relative newcomer, the transistor,
> > is replacing vacuum tube types because of the greater
> > inherent reliability, lower power consumption, and smaller
> > size. However, the complete replacement of the tube by the
> > transistor does not seem likely, for the latter has
> > shortcomings at high temperatures and high radiation
> > intensities and in the production of high power at high
> > frequencies. "
> >
> > ::Funny part is, that description is still pretty accurate, isn't it?
> > Especially the part about high radiation intensities and the production
of
> > high power; I guess it depends on your definition of "high."  I haven't
> > seen any solid state microwave ovens yet....-WB2WIK/6

Kind of also depends on your budget and other requirements (such as
reliability, infrastructure costs, etc.).  Solid state amplifiers have
pretty much replaced high power tubes in a lot of L-band radar applications,
particularly phased arrays.  Microwave ovens are a pretty cost sensitive
(and not power efficiency or thermal dissipation critical) application.

For radiation resistance and such, materials like Silicon Carbide and
Gallium Nitride are the up and coming product.