Read the part in W8JI's post again about grid dissipation "going through the roof".
A more basic translation: In most cases, with severe over driving (you mentioned 100 W into an amp that only needs 25 W...i.e. 300% over drive), if you do it very long.....and "very long" in that case can be a few seconds with some tubes, you physically destroy the grid in the tube with consequences you probably can understand.
To wit: grids (in most tubes used by hams) are relatively delicate fine wires and are easily damaged at truly abusive drive levels.
Moderate over driving causes your signal to splatter on adjacent frequencies, bother other hams and sound distorted. Translation: you are demonstrating to other people listening that you don't understand how an amplifier works or how to properly tune it.
Read the path where he ask the Question.
>>> If you are exciting your GG amp with 25 watts and you get the max amp output, what happens when you drive the same amp with 100watts Huh <<<
In all fairness to Robert, he asked a very VALID question.
Nowhere in his post did he say that's what he is doing. He simply asked " What IF"
Isn't that how we learn? Isn't he demonstrating to us that he wants to learn?
I too learned something [ in DETAIL ] here today.
ROBERT, good question.
Tom, Thank you! For taking the time to explain in DETAIL the answer to Robert's question.