Amateur Extra: What is a Parametric Amplifier?

Variable Capacitor

Today’s exam question comes from the Amateur Extra exam, Sub-element 7 (Practical Circuits) and Section B, (Amplifiers)…  [E7B20] What is a parametric amplifier? A. A type of bipolar operational amplifier with excellent linearity derived from use of very high voltage on the collector B. A low-noise VHF or UHF amplifier relying on varying reactance for … Read more

General: Increasing Inductance

This week’s General question comes from the section on circuit components. [G5C14] Which of the following components should be added to an inductor to increase the inductance? A. A capacitor in series B. A resistor in parallel C. An inductor in parallel D. An inductor in series The answer, is D. An inductor in series.  … Read more

General: Using Wind Power

Which of the following is a disadvantage of using wind as the primary source of power for an emergency station? [G4E11] A. The conversion efficiency from mechanical energy to electrical energy is less than 2 percent B. The voltage and current ratings of such systems are not compatible with amateur equipment C. A large energy … Read more