Having now done the WW2 Allies valve numbering, it would be churlish to not include the other sides' rohren numbering system now wouldn't it?   Now let's see what's left still to do, oh yes, the CV system, the Cyrillic system and the GPO numbering system, phew, better get blogging and then we can get back to the story of Mullard - what would you all like next -  ground breaking  products in the 1950's, semiconductor manufacture in the 1950's or expansions and endowments (yes there's more!) in the 1960s - you choose - let me know using the comments function? 



These German Eigantum valves carry an alphanumeric code in the sequence: two letters, two numbers, one letter, two numbers.

First letter

R - Reichswehr (Defence) encompassing Wehrmacht  (Army) and Kriegsmarine  (Navy)

Second letter

D - Decametric wavebands
G - Rectifier (Gleichrichter) or diode
K - Cathode ray tube
L - Transmitting or Power
V - Amplifier (Verstärker)

First & second number

Heater voltage

Third letter

A - Cathode ray indicator
D - Dual anode
G - Rectifier or diode
H - Hexode
L - Speed modulation
M - Magnetron
P - Pentode
T - Triode

Final number

Power output (W) or rectifier maximum delivery current (mA).



These German Eigantum der RLM valves carry an alphanumeric code in the sequence: two letters, one number.

First letter

L - Luftwaffe (German Air Force)

Second letter

B - Cathode ray tube
D - Decametric waves
F - Special type
G - Rectifier or diode
K - Stabiliser
M - Magnetron
S - Transmitting, wavelengths > 1 M
V - Amplifier, wavelengths > 1 M

First  number

Heater voltage