SWR Meter

Overview

A standing wave ratio meter sits in the feedline and samples the forward and reflected waves travelling along it. The ratio of the two tells you how well the load matches the transmitter: 1:1 means everything went out, 2:1 means about 11 percent came back.

A cross-needle meter shows both quantities at once, which is much easier to interpret than a single-needle instrument that must be switched between forward and reflected readings. The meter measures at its own position in the line, so readings taken at the transmitter with a tuner in circuit describe the match the transmitter sees, not the antenna.

Bands and modes

Band coverage

Modes

Safety note

Using it well

• Calibrate the meter on forward power before reading reflected.
• Take readings at low power first, then confirm at the power you will use.
• Measure at the antenna end as well as the transmitter end to find feedline loss.
• Remove the meter from the line once the antenna is known to be good.