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Perhaps someone can edumacate me. Where does a negative grid voltage originate from or how is it created/injected? The reason for the question is that that's where the problem lies in this radio. The grid (Pin 2 of V12) isn't going negative so it isn't stopping the flow of electrons.

"Because like charges repel, a negative charge on the grid (lots of excess electrons on the grid) repels the negatively charged free electrons trying to flow from the cathode through the grid to the plate. But a positive charge on the grid (scarcity of electrons) allows the free electrons to pass through the grid. If you fluctuate the electric charge on the 'control grid' you fluctuate the current flow between the cathode and plate. This effect is used as a signal amplifier by applying a low level guitar signal to the grid which controls the much larger flow of free electrons between the cathode and plate."

This is the key...

<blockquote data-quote="Champo" data-source="post: 774801" data-attributes="member: 60887">Perhaps someone can edumacate me. Where does a negative grid voltage originate from or how is it created/injected? The reason for the question is that that&#039;s where the problem lies in this radio. The grid (Pin 2 of V12) isn&#039;t going negative so it isn&#039;t stopping the flow of electrons. &quot;Because like charges repel, a negative charge on the grid (lots of excess electrons on the grid) repels the negatively charged free electrons trying to flow from the cathode through the grid to the plate. But a positive charge on the grid (scarcity of electrons) allows the free electrons to pass through the grid. If you fluctuate the electric charge on the &#039;control grid&#039; you fluctuate the current flow between the cathode and plate. This effect is used as a signal amplifier by applying a low level guitar signal to the grid which controls the much larger flow of free electrons between the cathode and plate.&quot;This is the key...</blockquote>

[QUOTE="Champo, post: 774801, member: 60887"] Perhaps someone can edumacate me. Where does a negative grid voltage originate from or how is it created/injected? The reason for the question is that that's where the problem lies in this radio. The grid (Pin 2 of V12) isn't going negative so it isn't stopping the flow of electrons. "Because like charges repel, a negative charge on the grid (lots of excess electrons on the grid) repels the negatively charged free electrons trying to flow from the cathode through the grid to the plate. But a positive charge on the grid (scarcity of electrons) allows the free electrons to pass through the grid. If you fluctuate the electric charge on the 'control grid' you fluctuate the current flow between the cathode and plate. This effect is used as a signal amplifier by applying a low level guitar signal to the grid which controls the much larger flow of free electrons between the cathode and plate." This is the key... [/QUOTE]

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