Besides classical functions and dB conversions, RadioCalc includes a converter of Power to field strength commonly used for EMC/EMS test-set-up. Also impedance can be represented as a function of reflection coefficient (somehow like an electronic Smith-chart). This and many other functions are obtained by clicking into the arrow of the “Conversion off” window.
Thanks to RadioCalc the different dB charts are obsolete by computing the ratios of Power (W) or Voltages (V) according to dB = 10*log(P2/P1) ou dB = 20*log(V2/V1).
Just for a trial : type 100/10 (or just 10) and push the dB button as the ‘W’ mode is chosen, the result will be 10 dB, then choose the ‘V’ mode by clicking in the V button (in the Quick dB window) push again dB, the result is now 20 dB.
From – Temcom – Consulting for test & measurement and electronics in France
(This was Earlier Radiocalc, i have now updated the link to the new site in France)