What is the term for interference from a signal at twice the IF frequency from the desired signal?

Q: What is the term for interference from a signal at twice the IF frequency from the desired signal?

The correct answer is B: Image response. The correct answer is B: Image response. The term for interference from a signal at twice the IF frequency from the desired signal is image response. Image frequencies are separated from the desired signal by 2×IF, causing interference. For amateur radio operators, this is a common receiver problem. Understanding this helps when troubleshooting interference.

Previous Next

Deep Dive: G8B02

The correct answer is B: Image response. The term for interference from a signal at twice the IF frequency from the desired signal is image response. Image frequencies are separated from the desired signal by 2×IF, causing interference. For amateur radio operators, this is a common receiver problem. Understanding this helps when troubleshooting interference.

Why Other Answers Are Wrong

Option A (Quadrature response): Incorrect. Quadrature response isn't the term for this - image response is the correct term. Quadrature is for I/Q signals, not image interference. Option C (Mixer interference): Incorrect. Mixer interference is too general - image response is the specific term for signals at 2×IF from desired. Mixer interference is too vague. Option D (Intermediate interference): Incorrect. Intermediate interference isn't the standard term - image response is the correct term. Intermediate interference isn't used.

Exam Tip

Interference from signal at 2×IF from desired = image response. Think 'I'mage 'R'esponse = 'I'nterference at 'R'emote frequency (2×IF away). Image frequencies are separated from desired signal by 2×IF, causing interference. Not quadrature, not mixer interference, not intermediate - just image response.

Memory Aid

Interference from signal at 2×IF from desired = image response. Think 'I'mage 'R'esponse = 'I'nterference at 'R'emote frequency. Image frequencies are separated from desired signal by 2×IF, causing interference. Common receiver problem.

Real-World Example

A receiver with 455 kHz IF: Desired signal at 14.200 MHz, LO at 14.655 MHz. Image frequency = 14.655 + 0.455 = 15.110 MHz (2×IF = 910 kHz from desired). A signal at 15.110 MHz can interfere - this is image response. Image frequencies are 2×IF away from desired signals.

Source & Coverage

Question Pool: 2023-2027 Question Pool

Subelement: G8B

Reference: 2023-2027 Question Pool · G8 - Signals and Emissions

Key Concepts

Image response Twice the IF frequency Interference Receiver problems

Official Pool Source

Question text and answer key are synchronized with the current NCVEC General Class pool and mapped to the G8B topic.