Updated: Dec 9, 2025 | Source: 2024-2028 Question Pool | Topic: E4B
E4B01E4B

Which of the following factors most affects the accuracy of a frequency counter?

Deep Dive: E4B01

The correct answer is B: Time base accuracy. Which of the following factors most affects the accuracy of a frequency counter is time base accuracy. The time base (reference oscillator) determines frequency counter accuracy. For amateur radio operators, this is important for test equipment. Understanding this helps when using frequency counters.

Why Other Answers Are Wrong

Option A: Incorrect. Input attenuator accuracy doesn't most affect accuracy - time base accuracy does. Attenuator isn't the most important. Option C: Incorrect. Decade divider accuracy doesn't most affect accuracy - time base accuracy does. Divider isn't the most important. Option D: Incorrect. Temperature coefficient of logic doesn't most affect accuracy - time base accuracy does. Temperature coefficient isn't the most important.

Exam Tip

Frequency counter accuracy most affected by = time base accuracy. Think 'F'requency 'C'ounter 'A'ccuracy = 'T'ime 'B'ase 'A'ccuracy. The time base (reference oscillator) determines frequency counter accuracy. Not attenuator, not divider, not temperature - just time base.

Memory Aid

Frequency counter accuracy most affected by = time base accuracy. Think 'F'requency 'C'ounter = 'T'ime 'B'ase. The time base (reference oscillator) determines frequency counter accuracy. Important for test equipment.

Real-World Example

A frequency counter: Its accuracy is most affected by time base accuracy. The time base is the reference oscillator used for counting. If the time base is inaccurate, all frequency measurements will be inaccurate. This is the factor - time base accuracy most affects counter accuracy.

Source & Coverage

Question Pool: 2024-2028 Question Pool

Subelement: E4B

Reference: 2024-2028 Question Pool · E4 - Amateur Practices

Key Concepts

Frequency counter accuracy Time base accuracy Reference oscillator Counter accuracy

Verified Content

Question from the official FCC Extra Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the E4B topic.