What can be done in a Heising modulation...

What can be done in a Heising modulation...

Question 1 of 27070HjZysiG1raJXtLkQlYOr

What can be done in a Heising modulation system to obtain 100% modulation?

Question 1 of 27070

Q

What can be done in a Heising modulation system to obtain 100% modulation?

🔍 Key Concepts

• Heising (constant-current) modulation places the modulator tube, modulation choke, and RF amplifier plate supply in series • In amplitude modulation, 100% modulation means the RF carrier is reduced to zero on negative peaks but not overdriven beyond that • How adding a series resistor or series capacitor in a DC supply path affects current flow and the audio modulation swing

💭 Think About

• Think about what has to happen to the RF amplifier plate (or final stage) DC and audio voltage for 100% modulation to occur in a Heising system • In a Heising circuit, would adding a resistor in series with the DC plate supply tend to increase or limit the available audio voltage swing at the plate? • Would placing a capacitor in a DC grid supply path actually allow DC to pass, or would it mainly pass AC (audio) and block DC—does that help you reach 100% modulation in a Heising setup?

✅ Before You Answer

• Be clear on where the Heising modulation choke and coupling capacitor are normally placed in a classic Heising circuit • Check whether a series resistor in a DC plate line is compatible with the idea of "constant current" that Heising modulation aims for • Verify whether a series capacitor in a DC grid supply is a realistic or standard way to achieve 100% plate modulation in this type of circuit