An interesting program and actually confirms that the British design for the H-Bomb was based around a spherical secondary instead of the Cylinder that was used by the US 2 stage weapons. The First two British H-bomb tests did actually give a Sizeable Fusion yield (300+ and 120+ KT) , while the middle test was in fact a bloody huge 700+KT Fission Bomb with maybe a bit of DT boosting. First Fizzle by the US was deliberate and that was to see how little Fissile material could be used, while the king of cocking up weapon designs yields was one Edward Teller!!!!