ARRL Technician Practice Exam

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Prepare for the ARRL Technician Exam. Study with flashcards and multiple choice questions, each question has hints and explanations. Get ready for your exam!

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What does an SWR reading of 4:1 indicate?

Perfect match between antenna and feed line
Moderate impedance match
Impedance mismatch
Excessive power output

The correct answer is: Impedance mismatch

An SWR reading of 4:1 indicates an impedance mismatch between the antenna and the feed line. SWR, or Standing Wave Ratio, is a measure of the efficiency of power transfer from the transmission line to the load (in this case, the antenna). A perfectly matched system would have an SWR of 1:1, meaning all the power is being sent to the antenna with no reflections. When the SWR reading is 4:1, it signifies that there is a fourfold difference between the maximum and minimum voltage standing waves, indicating a significant portion of the transmitted power is being reflected back. This can result in reduced effectiveness of the antenna and potential damage to the transmitter if high reflections occur. Understanding SWR is crucial for operators to ensure their setup is functioning optimally and to troubleshoot any issues related to power transmission.