[sdiy] Norvac in Porltand OR closing

[Paul Perry]

Yeah, I remember those radioactive tubes.. they were voltage regulator 
tubes, equivalent to a zener. A diode with low pressure inert gas, designed 
to break down and conduct at a fixed voltage (usually around 80V from 
memory).
The radioactive material was added to make sure there was no delay in 
conducting when the threshold was reached.
The commonest British ones were the OA2 and OB2.

paul perry Melbourne Australia

----- Original Message ----- > Radioactive tubes!
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