>and tubes like 811A's
>or 3-1000Z's are more difficult. If we look carefully, we see it is
>tubes with long thin grid leads that are most troublesome.
? amen, Mr. Rauch. As I understand it, the 3-1000z has a not-optimal
grid design that can be detected by visual inspection, 0.8 pF of
feedback is a bunch.
>They are
>often unstable no matter what the layout, because at some
>frequency the grid has a very high impedance to ground no matter
>how we ground the grid.
>
? indeed.
>In that case, we need to make sure the anode (or some other
>element) does not have a similar resonance.
>...
... ...
cheers
- Rich..., 805.386.3734, www.vcnet.com/measures.
end
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