Updated: Dec 9, 2025 | Source: 2022-2026 Question Pool | Topic: T3B
T3B10T3B

What frequency range is referred to as HF?

Deep Dive: T3B10

The correct answer is C: 3 to 30 MHz. HF (High Frequency) refers to the frequency range from 3 MHz to 30 MHz. This includes popular amateur bands like 80 meters (3.5-4.0 MHz), 40 meters (7.0-7.3 MHz), 20 meters (14.0-14.35 MHz), 15 meters (21.0-21.45 MHz), and 10 meters (28.0-29.7 MHz). HF frequencies are capable of long-distance communications through ionospheric propagation. The ionosphere can refract HF signals, allowing them to travel thousands of miles. HF is where most long-distance (DX) amateur radio communications occur. Technician licensees have limited HF privileges (primarily on 10 meters), while General and Extra class operators have full HF privileges.

Why Other Answers Are Wrong

Option A: Incorrect. 300-3000 MHz is UHF, not HF. HF is much lower. Option B: Incorrect. 30-300 MHz is VHF, not HF. HF is 3-30 MHz. Option D: Incorrect. 300-3000 kHz is 0.3-3 MHz, which is mostly below the HF range. HF is 3-30 MHz.

Exam Tip

HF = 3-30 MHz. Remember: HF (High Frequency) is 3 MHz to 30 MHz. This includes 80m, 40m, 20m, 15m, and 10m bands where long-distance communications are possible.

Memory Aid

**H**F = **3**-**3**0 **M**Hz (think 'HF = 3-30 MHz')

Real-World Example

You're operating on 28.4 MHz, which is in the 10-meter band. This frequency is within the HF range (3-30 MHz). Your 10-meter signal can be refracted by the ionosphere, allowing contacts over thousands of miles, which is characteristic of HF propagation.

Source & Coverage

Question Pool: 2022-2026 Question Pool

Subelement: T3B

Reference: FCC Part 97.303

Key Concepts

HF Frequency range 3-30 MHz Ionospheric propagation

Verified Content

Question from the official FCC Technician Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the T3B topic.