How would you determine the cathode-bias...

🔍 Key Concepts

• Cathode-bias (self-bias): how raising the cathode above ground creates a negative grid-to-cathode voltage • Relationship between bias voltage, current, and resistance using Ohm’s Law • Difference between plate current and total cathode current (including screen current in tetrodes/pentodes)

💭 Think About

• How does the IR drop across the cathode resistor relate to the grid-to-cathode bias voltage? • When you know the desired DC bias voltage and the no-signal cathode current, how can Ohm’s Law help you find the needed resistance value? • For tubes with a screen (tetrodes/pentodes), which currents actually flow through the cathode resistor?

✅ Before You Answer

• Use Ohm’s Law: R = V / I with bias voltage and total no-signal cathode current • Remember that in tetrodes and pentodes, screen current also flows through the cathode, not just plate current • Check which options describe parts of the same correct method rather than different, conflicting methods

How would you determine the cathode-bias resistance necessary to provide correct grid bias for an amplifier?

Bias equals the IR drop across the cathode

Bias is found by dividing the desired DC bias voltage by the total no-signal cathode current

For a tetrode or pentode, the screen current must be added to the plate current

All of the above

🔍 Key Concepts

💭 Think About

✅ Before You Answer