I've just bought another BSA charging set (don't ask why, I have no idea other than it was stunningly cheap!).
Anyway, I though it was a little unusual in that it is a 250W American spec. version.
It has the same 100cc BSA engine and fuel tank base but this has been down rated to 1800 RPM (as opposed to the 2200 RPM for the British Army version) which probably accounts for the reduced 250W output rather than the 300W of the British unit.
It has two outputs: 15V DC and 230 V AC @ 60 Hz.
Picture at:
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For all I know these are probably ten-a penny but it struck me as unusual that a British engine was used for an American genset. Possibly the whole thing was made by BSA for the US Army or maybe they bought the engine and base unit and added their own generator to it. There is no real clues on the thing other than various labels referring to American specifications and the oil requirement is apparently 'Oil Lub M-120' (very un-British).