## What is the approximate length, in inches, of a quarter-wavelength vertical antenna for 146 MHz?

#### 112

While 112 inches is a substantial length, it is **incorrect **because it’s significantly longer than a quarter wavelength for 146 MHz, which results from a miscalculation of the wavelength formula.

#### 50

50 inches **is not the correct length** because it is longer than the calculated quarter wavelength, indicating an error in applying the wavelength formula for 146 MHz.

#### 19

**19 inches is correct** as it matches the formula output, converting the calculated 1.60 feet to inches for a quarter-wavelength antenna at 146 MHz.

#### 12

12 inches is shorter than the calculated quarter wavelength, **making it incorrect** for a quarter-wavelength antenna intended to operate at 146 MHz.

#### Explanation

Understanding the length of antennas is crucial for efficient radio communication. The question asks about the approximate length of a quarter-wavelength vertical antenna for 146 MHz. Antenna length is directly related to the frequency of the signal it is designed to receive or transmit. The formula to calculate the length of a quarter-wave antenna is L = 234 / F, where L is the length in feet and F is the frequency in megahertz. Applying the given frequency of 146 MHz to this formula gives 1.60 feet. Converting feet to inches (1 foot = 12 inches) results in approximately 19.2 inches, hence nearly 19 inches. This quarter-wave length is essential because it ensures the antenna can effectively resonate at the given frequency, enabling optimal signal transmission and reception. Incorrect lengths affect the antenna’s efficiency, leading to poor communication quality.

T9A08 2022-2026