[Amps] more dangers in our shack

[Nils Petter Pedersen]

While I am at it... there are more dangers in our shack:
Apart from the more obvious danger of electromagnetic overexposure
using our 3cx 15 000's and the likes...:-)
A lot of power tubes and other devices contain Berryllium oxide.
I have seen amps for the ham market that used conduction cooling
by means of big blocks of Berryllium oxide (BeO) making thermal
connectors to a back panel heatsink. I have also seen a fellow ham
grinding and sanding these blocks to make a tight fit..
That process left a cover of fine dust on his workbench. He blew that
away using an air hose....
Well... I evacuated that room immediately and left him alone with the problem..
Here is what I told him BEFORE he started on his project :
Beryllium oxide (Beryllia):

BeO is most often used as an electronic substrate, exploiting its high thermal conductivity and good electrical resistivity to give an effective heat sink.  The material is found particularly in high power devices or high density electronic circuits for high speed computers.


Extremely toxic by inhalation and ingestion. Typical LD50s for beryllium compounds are between 0.5 and 5 mg kg-1. Probable human carcinogen. Serious respiratory irritant. May be harmful by skin contact. 

Use only under properly controlled conditions. Avoid breathing dust or powder. Use safety glasses, gloves, good ventilation. Treat as a probable carcinogen. Prepare a full risk assessment before starting work. 

Have a nice weekend :-)
Peter
LA7SL