Ham Radio General Class Practice Test

What is the approximate length for a 1/2-wave dipole antenna cut for 14.250 MHz?

1. 8 feet

2. 16 feet

3. 24 feet

4. 32 feet

The correct answer is: 32 feet

The length of a half-wave dipole antenna can be calculated using the formula: \[ \text{Length (feet)} = \frac{468}{\text{Frequency (MHz)}} \] When using this formula for a frequency of 14.250 MHz: \[ \text{Length} = \frac{468}{14.250} \approx 32.8 \text{ feet} \] Rounding this to a more practical length for antenna construction leads to approximately 32 feet. This length ensures that the antenna, when installed, will efficiently resonate at the target frequency, providing optimal performance in terms of radiation pattern and bandwidth. Other options do not correctly reflect the calculations for a half-wave dipole at this frequency. Lengths significantly shorter than 32 feet would not achieve the resonance needed for effective operation at 14.250 MHz, while lengths much longer would not be suitable for practical installation and tuning in the intended band.