Vintage Indicators

Michael Watterson's picture

Special Indicators (Vintage)

The basic types of vintage indicators are (1) Neon (or Argon), (2)Triode like miniature Cathode Ray Tube ( (3) Vacuum Fluorescent Display (VFD, which is also based on Triode and CRT!), and (4) Lamp Filament.Geissler Discharge tubes
were a Victorian novelty. Actual Neons Indicators since about 1910.
Neon signs are mostly actually nothing to do with Neon, but coloured 
Fluorescent Tubes (Mercury Discharge like CFLs and Tubes in a Kitchen),
now only the small Neon lamps are made as mains indicators. Magic Eyes
from 1934/1935 till late 1960s A kind of miniature CRT (like used in old
TV screens). They replaced specialised Neons as tuning indicators
within a year. Vacuum Fluorescent Displays (VFDs) are first Calculators
from 1967, now widely used in new designs  cars, HiFi, DVD/BluRay and
Set-box adaptors for Satellite/TV. Actually based also on 1890s CRT but
only 25V! For bright daylight operation they are better than LED or LCD,
support graphics and custom shapes

Moved here to Radicalvalves.com