Which of the following frequency ranges is associated with the decameter band?

Which of the following frequency ranges is associated with the decameter band?

• A. 3 MHz - 30 MHz
• B. 3 Hz - 30 Hz
• C. 118 MHz
• D. 400 MHz

Answer: (A)

The decameter band refers to radio waves with wavelengths in the decameter range, about 10 to 100 meters. Frequency and wavelength relate by f ≈ 300 / λ (with f in MHz and λ in meters). For λ = 100 m, f ≈ 3 MHz; for λ = 10 m, f ≈ 30 MHz. So the decameter band spans roughly 3 to 30 MHz. The other options don’t fit: 3 Hz to 30 Hz is ELF, far too low; 118 MHz is in the VHF range; 400 MHz is UHF. Hence the correct range is 3 to 30 MHz.

The decameter band refers to radio waves with wavelengths in the decameter range, about 10 to 100 meters. Frequency and wavelength relate by f ≈ 300 / λ (with f in MHz and λ in meters). For λ = 100 m, f ≈ 3 MHz; for λ = 10 m, f ≈ 30 MHz. So the decameter band spans roughly 3 to 30 MHz. The other options don’t fit: 3 Hz to 30 Hz is ELF, far too low; 118 MHz is in the VHF range; 400 MHz is UHF. Hence the correct range is 3 to 30 MHz.