Deep Dive: E4E06
The correct answer is C: The appearance of unstable modulated or unmodulated signals at specific frequencies. What type of electrical interference can be caused by computer network equipment is the appearance of unstable modulated or unmodulated signals at specific frequencies. Computer network equipment generates RF interference at specific frequencies. For amateur radio operators, this is important for troubleshooting interference. Understanding this helps when identifying interference sources.
Why Other Answers Are Wrong
Option A: Incorrect. Loud AC hum in audio output isn't from computer network equipment - computer equipment causes RF signals at specific frequencies. AC hum isn't the interference. Option B: Incorrect. Clicking noise at intervals isn't from computer network equipment - computer equipment causes RF signals at specific frequencies. Clicking noise isn't the interference. Option D: Incorrect. Whining-type noise that pulses isn't from computer network equipment - computer equipment causes RF signals at specific frequencies. Whining noise isn't the interference.
Exam Tip
Computer network interference = appearance of unstable modulated or unmodulated signals at specific frequencies. Think 'C'omputer 'N'etwork = 'C'reates 'N'arrowband signals. Computer network equipment generates RF interference at specific frequencies. Not AC hum, not clicking, not whining - just unstable signals at specific frequencies.
Memory Aid
Computer network interference = appearance of unstable modulated or unmodulated signals at specific frequencies. Think 'C'omputer 'N'etwork = 'S'ignals at 'F'requencies. Computer network equipment generates RF interference at specific frequencies. Important for troubleshooting interference.
Real-World Example
Computer network equipment: It can cause electrical interference appearing as unstable modulated or unmodulated signals at specific frequencies. For example, Ethernet switches, routers, and Wi-Fi equipment can generate RF signals that interfere with amateur radio. This is the interference type - unstable signals at specific frequencies.
Source & Coverage
Question Pool: 2024-2028 Question Pool
Subelement: E4E
Reference: 2024-2028 Question Pool · E4 - Amateur Practices
Key Concepts
Verified Content
Question from the official FCC Extra Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the E4E topic.