>
>
>Hi,
>
>Rich wrote...
>
>> // Sounds good. How did you protect the screen from loss of anode
>> potential?.
>
>This reminded me of a 4-65A amp (class C) that I built for 40m many
>years ago. After installing a bigger fan (cooler is gooder) I hooked
>everything back up to the power supply, which was in a separate
>cabinet.
>
>Well, almost everything. Not the anode supply; but the "stiff"
>screen supply was connected.
>
>The first time I keyed up, the screen potential was applied, and the
>tube performed like one of the old focal-plane shutter type
>flashbulbs. It gave off a very bright light, nearly white... none of
>that wussy orange color... for a fraction of a second (1/4? 1/2
>second?)and I was left with a 3-65A.
>
A rare bottle.
>It was an expensive show in a brief time.
>
>In my tetrode amplifiers since that time, screen voltage application
>always requires the presence of appropriate anode voltage (and
>appropriate control grid bias, as well!) whatever the method of
>screen regulation (or lack thereof.)
>
Amen, George
- R. L. Measures, a.k.a. Rich..., 805.386.3734,AG6K,
www.vcnet.com/measures.
end
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