[Amps] AL-80B questions

[Tom Rauch]

> Here we go again (GROANNNNNNNNNNNNNNNN.............)
>
> Conrad G0RUZ

It isn't that bad Conrad. This is like engineering triage. We should help
those who aren't terminal, and can still be helped. Sometimes we have to
accomplish that by pointing out fatal mistakes by those who are far beyond
being helped.

The best way to learn how things work is to analyze engineering
misconceptions. It's easy, and takes almost no time at all, to show most
people the "parasitic" bending theory is total nonsense, and people can
actually learn from it.

For example, normal peak 3-500Z filament current is 20 amperes. Saturated
peak emission is about 7.5 amperes when the grid is 1000v positive with
respect to cathode. Most people are smart enough to understand that a 30%
increase in current in a nanosecond isn't going to whack a filament out of
alignment. Especially when normal peak inrush is many times larger and
doesn't cause problems in properly manufactured tubes.

What is important is this gives us a chance to prove excessive thermal
cycling and manufacturing defects in the tube are the root cause of
failures, and dispel some of the pathological science.

73 Tom