SWR converter
Convert SWR to return loss and back, and see how much of your transmitter’s power is actually coming back down the feeder.
That's about the same as a good match. About 4% of the power is reflected back.
What it means
How good is that match?
SWR is measured at the meter, not at the antenna. Feeder loss flatters the reading: a long lossy cable can make a bad antenna look well matched.
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Learn
Three things worth knowing
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SWR 2:1 loses half a decibel
11% of the power comes back, which is 0.5 dB of mismatch loss. SWR 3:1 reflects 25%, and even that is only 1.25 dB.
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Standing waves on the line
The forward and reflected waves add and cancel along the cable, leaving a fixed pattern of high and low voltage. SWR is simply the highest divided by the lowest.
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Low SWR is not a good antenna
A dummy load has a perfect 1:1 match and radiates nothing at all. SWR tells you about the match, not about how well the antenna works.
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Popular match conversions
Background
About SWR
When an antenna does not match the feeder, some of the power turns round and comes back. SWR describes that as a ratio of voltages along the line; return loss describes the same thing in decibels.
An SWR of 2:1 sounds alarming but reflects only 11% of the power — a loss of half a decibel, which nobody can hear.