[ARC5] Australian AWA "Radiotron" 807 Valve

[Neil]

> I'm working on a neat RAAF AT5 transmitter.
> One of the tubes is an Australian-made AWA Radiotron
> type 807.  Engraved on the brown bakelite base
> is a capital "D" followed by an up-pointing arrow 
> and another capital "D."   The arrow is between the 
> filament pins and the two "D"s align with the fil pins.
> Anyone know the significance of this marking?

Probably "Department of Defence", ie. marking the
item as Australian government property. The alignment
with the filament pins is probably not intentional.

http://en.wikipedia.org/wiki/Department_of_Defence_(Australia)

73 de Neil ZL1ANM