One question, 16 responses, 3 answers. I have to ask why Algernon Lacey, Capt Crash, Fallen eagle, Chicken6. A and C, Mount'in Man, Tallbloke and New Bloke felt impelled to post comments that had sod all to do with the question that was asked. Could it be an ego problem?
Congratulations to Oleo, Virgin and John Farley for making creditable attempts to answer, in a text based medium, what really requires a diagrammatic explanation.
I shall now don my flack jacket and await the inevitable stream of vituperation from those whose over-inflated egos I have dented.