What is the primary purpose of the suppressor grid in a pentode?

What is the primary purpose of the suppressor grid in a pentode?

• A. Is highly negative to return secondary emission to the plate
• B. Reduces interelectrode capacitance between control grid and plate
• C. Both of the above
• D. None of the above

Answer: (A)

The primary purpose of the suppressor grid in a pentode is indeed to be highly negative to control secondary emission and return electrons back to the plate. In a pentode, the suppressor grid is positioned between the plate and the screen grid, and its negative voltage effectively repels any secondary electrons that have escaped from the plate during the emission process. When a positive voltage is applied to the plate, some electrons may collide with the plate's surface and be emitted as secondary electrons. If these secondary electrons were to travel to the screen grid, they could disrupt the operation of the amplifier by reducing the current flow through the device. The suppressor grid helps to mitigate this by keeping the secondary electrons within the vicinity of the plate and preventing them from reaching the screen grid, thus maintaining efficient operation and improving overall performance. While reducing interelectrode capacitance is an important aspect of pentode design, it is not the main function of the suppressor grid. The suppressor grid's primary role is specifically related to managing secondary emissions, making the first choice the correct answer in this context.

The primary purpose of the suppressor grid in a pentode is indeed to be highly negative to control secondary emission and return electrons back to the plate. In a pentode, the suppressor grid is positioned between the plate and the screen grid, and its negative voltage effectively repels any secondary electrons that have escaped from the plate during the emission process.

When a positive voltage is applied to the plate, some electrons may collide with the plate's surface and be emitted as secondary electrons. If these secondary electrons were to travel to the screen grid, they could disrupt the operation of the amplifier by reducing the current flow through the device. The suppressor grid helps to mitigate this by keeping the secondary electrons within the vicinity of the plate and preventing them from reaching the screen grid, thus maintaining efficient operation and improving overall performance.

While reducing interelectrode capacitance is an important aspect of pentode design, it is not the main function of the suppressor grid. The suppressor grid's primary role is specifically related to managing secondary emissions, making the first choice the correct answer in this context.