[r-t] Double Cambridge cyclic bob Minor

[Jonathan Agg]

Hi,

I've been trying to get a touch of Double Cambridge Cyclic bob minor 
suitable for a quarter peal (I read an archive for this list that said 
an extent was impossible) so was instead trying to find a shorter length 
e.g. 540. However, I've got completely baffled by the falseness, and 
haven't made any serious progress. W H W sH twice gives a 240, but I've 
not managed to extend this further. Does anyone have a composition, or 
means for working one out?

Can anyone prove why an extent is not possible?

Cheers,
Jonathan