Among its main groups, the
reception and transmission valve, basically they are different
considering only its operational principle. In this way
hence in the former its most important factor is the
amplification without distorsion, in the latter it is
its output power. Therefore, the transmission valve is
just a kind of reception valve converted to handle
high output power and so operating with high plate voltage.
Its evolution is related with several advances in the
thermionic art such as: better getter technics, as well
as improved anode radiation's dissipation.
of some types of transmission valves:
A = Valve
801A, power triode type used toried tungsten filament
as amplifying of high frequency, oscilltor and power
amplifying for radio frequency.