How would you perform a basic antenna system impedance check using a portable SWR meter?

• A. Connect the meter, calibrate, measure forward and reflected power, and adjust for minimum SWR
• B. Disconnect the antenna and measure coil resistance with a multimeter
• C. Use the meter only to measure RF output without calibration
• D. Replace the feedline with a test cable and assume good match

Answer: (A)

Using an SWR meter to check impedance is about seeing how well the antenna system is matched to the transmitter by comparing forward RF power to reflected RF power. In practice, you place the meter in series with the feedline, calibrate it so the reference plane is at the antenna input, then transmit a test signal and read both forward and reflected power. The ratio (or the displayed SWR) tells you how much power is being reflected due to impedance mismatch. You then adjust the antenna, feedline, or any matching network to reduce the reflected power, driving the SWR down toward a minimum across the frequencies you care about. This direct RF measurement reveals whether the system is properly matched, which is the whole point of an impedance check.

Why the other options don’t fit: measuring coil resistance with a DC multimeter doesn’t tell you how the antenna presents at RF, so it won’t reveal mismatch. using the meter only to measure RF output without calibration won’t show how much is reflected or whether the system is matched. replacing the feedline and assuming a good match skips any measurement and could hide a real impedance problem.