Deep Dive: T3B06
The correct answer is D: Wavelength in meters equals 300 divided by frequency in megahertz. The formula for converting frequency to wavelength in meters is: wavelength (meters) = 300 / frequency (MHz). This formula works because the speed of light is approximately 300,000,000 meters per second, and when you divide by frequency in megahertz (millions of hertz), you get the simplified formula using 300. This is a fundamental formula in amateur radio. For example, 146 MHz (2 meters) gives: wavelength = 300 / 146 = 2.05 meters. The formula works because: wavelength = speed of light / frequency = 300,000,000 m/s / (frequency in Hz). When frequency is in MHz, you divide by 1,000,000, which simplifies to 300 / frequency(MHz).
Why Other Answers Are Wrong
Option A: Incorrect. Multiplying frequency by 300 would give a very large number, not a wavelength. The relationship is division, not multiplication. Option B: Incorrect. Dividing frequency in hertz by 300 doesn't work because the numbers are too large. You need frequency in MHz. Option C: Incorrect. Dividing frequency in MHz by 300 gives the wrong result. You need to divide 300 by the frequency.
Exam Tip
Wavelength formula = 300 / MHz. Remember: Wavelength in meters = 300 divided by frequency in megahertz. This is one of the most important formulas to memorize.
Memory Aid
**W**avelength = **3**00 / **M**Hz (think 'W = 3/M' = 300 divided by MHz)
Real-World Example
You want to know the wavelength of 28.4 MHz (10 meters). Using the formula: wavelength = 300 / 28.4 = 10.56 meters. This confirms it's in the 10-meter band. For 146 MHz (2 meters): wavelength = 300 / 146 = 2.05 meters, confirming it's approximately 2 meters.
Source & Coverage
Question Pool: 2022-2026 Question Pool
Subelement: T3B
Reference: FCC Part 97.3
Key Concepts
Verified Content
Question from the official FCC Technician Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the T3B topic.