Question T7C04
From subelement T7 - T7C
What reading on an SWR meter indicates a perfect impedance match between the antenna and the feed line?
Why is this correct?
A 1:1 SWR reading indicates perfect impedance match because it means the antenna system impedance equals the feed line impedance, with no reflected power. At 1:1, all forward power transfers efficiently to the antenna. The other options are incorrect: 50:50 represents impedance values, not SWR ratio; Zero would indicate no power measurement; Full Scale suggests maximum reflection, the opposite of perfect match.
Memory tip
Remember SWR as a simple fraction: forward power divided by reflected power. When impedances match perfectly, there's no reflection, making this ratio 1:1. Look for the colon (:) in SWR readings—it always expresses a ratio, never individual component values or meter positions.
Learn more
In amateur radio practice, achieving 1:1 SWR is the gold standard because it ensures maximum power transfer from your transmitter through the transmission line to your antenna system. While SWR below 2:1 is generally acceptable for most operations, the 1:1 reading specifically indicates zero reflected power, meaning your 50-ohm transmitter, coaxial cable, and antenna impedances are perfectly matched according to transmission line theory.
Think about it
Why do you think a perfect impedance match (1:1 SWR) doesn't guarantee your antenna will radiate effectively into space?