SWR Chart

Handy SWR chart shows what the numbers mean, in both how much signal is radiated from the antenna and how much power is reflected back to the transmitter where it is dissipated as heat in the final.

It is easy to see that a too-high SWR leads to an overheated final amplifier because more and more power is bounced back from the antenna into the radio and has nowhere else to go.

The chart assumes a 4 Watt CB, but is accurate for ham radios and other power levels, just use a calculator with the % columns.

Many people obsess over SWR, but anything under 2:1 won't really be noticeable and 2.5:1 or less should not harm a stock transmitter (OK well read the manual to be sure).

With a turned-up radio, the little final is still only rated for those few watts, so a high SWR becomes much more dangerous to it.

Parts of the chart are originally from Firestik.