Brand

•  EIMAC
•  MARQUES DIVERSES / VARIOUS BRANDS
•  PENTA
•  RPC
•  TELEFUNKEN
•  THOMSON CSF
•  USA

Interests

•  Audiophiles
•  Collectors
•  Guitarists
•  Radio hams

Socket

•  B5A - Subminiatur (5 wires in line)
•  K8A - Octal (8 pins)
•  S5G (Geant Special Support 5 Stifte - for 3-500Z)
•  UX Base (300B type, 4 pins)

Heating parameters

•  1.2 to 1.4V
•  2.5V
•  4V
•  5V
•  6.3V
•  6V
•  7.5V
•  8V
•  26.5V

Décennie

•  1920
•  1930
•  1940

Connection on the top

•  With
•  Without