On Saturday, 8 June 2019 09:45:19 UTC+1, Harry Bloomfield wrote:
Steve Walker expressed precisely :

Of a sinewave, not a half-wave rectified sine wave.

Sinewave: 339V / sqrt(2) = 240V RMS

Half-wave rectified sinewave: 339V / 2 = 169.5V RMS

SteveW

169.5v x 0.707= 119.83v RMS..

Lol.