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G4A - Amateur Radio Practices

General Class

Station receivers: sensitivity, selectivity, noise reduction, intermodulation

13 questions | Updated: Dec 9, 2025

All G0A G0B G1A G1B G1C G1D G1E G2A G2B G2C G2D G2E G3A G3B G3C G4A G4B G4C G4D G4E G5A G5B G5C G6A G6B G7A G7B G7C G8A G8B G8C G9A G9B G9C G9D
G4A01

What is the purpose of the notch filter found on many HF transceivers?
G4A02

What is the benefit of using the opposite or “reverse” sideband when receiving CW?
G4A03

How does a noise blanker work?
G4A04

What is the effect on plate current of the correct setting of a vacuum-tube RF power amplifier’s TUNE control?
G4A05

Why is automatic level control (ALC) used with an RF power amplifier?
G4A06

What is the purpose of an antenna tuner?
G4A07

What happens as a receiver’s noise reduction control level is increased?
G4A08

What is the correct adjustment for the LOAD or COUPLING control of a vacuum tube RF power amplifier?
G4A09

What is the purpose of delaying RF output after activating a transmitter’s keying line to an external amplifier?
G4A10

What is the function of an electronic keyer?
G4A11

Why should the ALC system be inactive when transmitting AFSK data signals?
G4A12

Which of the following is a common use of the dual-VFO feature on a transceiver?
G4A13

What is the purpose of using a receive attenuator?