[Arny Krueger]

"Peter Wieck" wrote in message

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.

I'm under the impression that the power amps were in series across the B+
power, which was on the order of several kV.

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?

Both were Hawk, which was mobile with 30 minute take-down, 30 minute setup.

That power- supply would have to be pretty
rugged under those conditions.

Some shock mounting for especially the 300Bs. Most of the tubes were wire-in
types sitting in metal clips/heat sinks.