**Calculator & SWR Function_key as html text**PA2ION, 2018

^{©}

The calculator has a function knob for conversion of '*SWR value to rest energy to the antenna as percent*'

The calculator is built up with HTML text only and is tested to be successfully with both Chrome and Firefox.

Support of braces enable more complex calculations. - *Exponential calculations are not supported!* -

For this example a 'roundabout way' is used to avoid the exponent.

Picture: View of the calculator after adaption of the window dimension.

**SWR**

Impedance difference between antenna and feeder decrease the amount of RF power flowing to the antenna surface.

The SWR meter indicates the health of these constructions. SWR values are between ‘1’(=best match) and higher.

By pressing the function button input of SWR values will be calculated as the remaining energy fraction to the antenna.

Calculation of SWR to Efficiency(%) values:

= (1-(((SWR-1))/((SWR+1)))^{2})*100)

= ((1-(((SWR-1))/((SWR+1)))*(((SWR-1))/((SWR+1))))*100)