Valves indicated with a '*' have a different heater current, and
are therefore not direct replacements in a.c./d.c. receivers.
Where necessary, the name of the manufacturer is indicated in
bracketed italics immediately following the valve type number.
Examples: AC/DD (FM), DD6 (C), PT4 (F).
C Cossor
EK Ekco
EM Ediswan Mazda
F Ferranti
H Hivac
M Mullard
MO Marconi Osram
T Tunsgram