> Rich writes:
>
> Joe -- Are you saying that Eimac's 8877 design team told you they did
> not choose to use Eimac's grid-grounding collet during testing of the
> 8877?
No, I'm simply saying that the Eimac tube guys that I knew and worked
with said a lot of what passes for "truth" is a bunch of nonsense.
In their experience, every case of "parasitic problems" in 8877 amps
could be resolved by properly grounding the grid and resolving stupid
layout issues (like stray coupling - e.g., unbypassed control wiring -
from the output to the input). This also applied to larger "tubes
with handles" designed for applications like VHF TV visual service.
This does not apply to tubes with long internal grid leads (e.g. 811A,
572B, etc.). It is impossible to "properly ground" the grid of tubes
like that ... then other means of eliminating parasitics may be needed.
73,
... Joe, K4IK
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