T3A07: What weather condition might decrease range at microwave frequencies

Q: What weather condition might decrease range at microwave frequencies?

The correct answer is C: Precipitation. The correct answer is C: Precipitation. Precipitation (rain, snow, fog) can decrease range at microwave frequencies because water droplets absorb and scatter microwave signals. The higher the frequency, the more pronounced this effect becomes. Microwave signals are particularly affected by water in the atmosphere. Rain, snow, and even heavy fog contain water that absorbs microwave energy, converting it to heat. This absorption reduces signal strength and decreases communication range. This is why microwave links can be affected by weather - heavy rain can significantly reduce range and signal quality. The effect is much more pronounced at higher microwave frequencies (like 10 GHz and above) than at lower frequencies.

Updated: Dec 9, 2025 | Source: 2022-2026 Question Pool | Topic: T3A

T3A07T3A

What weather condition might decrease range at microwave frequencies?

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Deep Dive: T3A07

The correct answer is C: Precipitation. Precipitation (rain, snow, fog) can decrease range at microwave frequencies because water droplets absorb and scatter microwave signals. The higher the frequency, the more pronounced this effect becomes. Microwave signals are particularly affected by water in the atmosphere. Rain, snow, and even heavy fog contain water that absorbs microwave energy, converting it to heat. This absorption reduces signal strength and decreases communication range. This is why microwave links can be affected by weather - heavy rain can significantly reduce range and signal quality. The effect is much more pronounced at higher microwave frequencies (like 10 GHz and above) than at lower frequencies.

Why Other Answers Are Wrong

Option A: Incorrect. High winds don't directly affect microwave propagation. They might move antennas or cause mechanical issues, but they don't absorb signals. Option B: Incorrect. Low barometric pressure doesn't significantly affect microwave propagation. Weather fronts might, but pressure itself doesn't. Option D: Incorrect. Colder temperatures don't decrease microwave range. In fact, colder air can sometimes improve propagation slightly.

Exam Tip

Microwave range decrease = Precipitation. Remember: Precipitation (rain, snow, fog) decreases microwave range because water absorbs microwave signals. Higher frequencies are more affected.

Memory Aid

**M**icrowave **R**ange **D**ecrease = **M**oisture **R**educes **D**istance (think 'MRD = MRD' = Moisture Reduces Distance)

Real-World Example

You're operating a 10 GHz microwave link that normally works over 20 miles. During a heavy rainstorm, the link becomes unreliable and range drops to only a few miles. The rain is absorbing your microwave signal energy. When the rain stops, your range returns to normal. This is why microwave links can be weather-dependent.

Source & Coverage

Question Pool: 2022-2026 Question Pool

Subelement: T3A

Reference: FCC Part 97.3

Key Concepts

Precipitation Microwave frequencies Signal absorption Range reduction

Verified Content

Question from the official FCC Technician Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the T3A topic.