[Peter Wieck]

On Dec 1, 9:38*am, "Arny Krueger" wrote:

I also have seen some references to special high-reliability 300Bs used as
booster amplifiers in the early transoceanic cables, say from the 30s. *I
did some checking around and could only find specific *references to the
cables they laid in the 50s, which used *physically smaller pentodes.

Interesting. I wonder how they solved the high-voltage problem, or
maybe they didn't and so moved on to different tubes.

The power supplies of the AN/MPQ 34 and AN/MPQ 36 radars I worked on in the
late 60s used 300Bs for series regulators for the B+ supplies all over the
radar (3 total power supplies, about 6 RU each). I think there were 8 300Bs
per unit

Makes sense - wasn't the 34 used on mobile missile systems? That power-
supply would have to be pretty rugged under those conditions.

Peter Wieck
Melrose Park, PA