What is the length in feet of a 1-wavelength antenna at 14.0 MHz?

What is the length in feet of a 1-wavelength antenna at 14.0 MHz?

• A. 66.9 ft
• B. 133.7 ft
• C. 93.4 ft
• D. 49.2 ft

Answer: (A)

A 1-wavelength length equals the wavelength of the radio wave. Use λ = c / f. With f = 14.0 MHz, λ ≈ 3.00×10^8 m/s / 14×10^6 Hz ≈ 21.4 meters. Convert to feet: 21.4 m × 3.28084 ≈ 70.2 feet. So the full-wavelength length at 14 MHz is about 70 feet. Among the given options, 66.9 feet is the closest match to that value, and is the best choice when rounding constants and unit conversions. The other options correspond to lengths that are notably different from one full wavelength at this frequency.

A 1-wavelength length equals the wavelength of the radio wave. Use λ = c / f. With f = 14.0 MHz, λ ≈ 3.00×10^8 m/s / 14×10^6 Hz ≈ 21.4 meters. Convert to feet: 21.4 m × 3.28084 ≈ 70.2 feet. So the full-wavelength length at 14 MHz is about 70 feet. Among the given options, 66.9 feet is the closest match to that value, and is the best choice when rounding constants and unit conversions. The other options correspond to lengths that are notably different from one full wavelength at this frequency.