Which of the following is used to determine if an antenna is resonant at the desired operating frequency?

• A. A multimeter
• B. An antenna analyzer
• C. A SWR meter
• D. A power meter

Answer: (B)

An antenna analyzer is the correct tool for determining if an antenna is resonant at the desired operating frequency. It works by analyzing the impedance of the antenna at different frequencies. When an antenna is resonant, it will have a specific impedance that matches the transmission line, typically close to 50 ohms for most ham radio applications.

An antenna analyzer provides readings such as SWR (Standing Wave Ratio), which can indicate how well the antenna is matched to the transmission line. By tuning the frequency on the analyzer, the operator can see if adjustments are necessary to achieve resonance at their desired operating frequency. This feature is crucial for ensuring efficient transmission and minimizing signal loss.

While a multimeter can measure resistance and continuity, it does not provide information relevant to the frequency characteristics of the antenna. An SWR meter measures the power reflected back from the antenna due to impedance mismatch but does not provide detailed analysis of resonance. A power meter measures the power output from the transmitter but does not indicate the antenna’s resonance at a specific frequency. Thus, the antenna analyzer is distinctly suited for assessing antenna resonance.