Ron's mechanism guide will be of marginal help. He only covers the 45mechanisms. There are a lot of differences between the 45 and 78 machines.Same basic concepts of operation, but lots of little differences. Seeburg manuals are excellent on theory of operation. I had a problem with my M100Aafter getting the selection receiver rebuilt. It wasn't moving the selection levers when a selection was made. It turned out to be a dirty contact in theselection receiver. I've had this machine since 1975, but I never would havefigured it out if I didn't have the manual. The lever should be cancelled as the last operation as the tone arm sets down on the record. Can't tell you off thetop of my head where the pulse comes from though. You've really set yourself a chore in trying to convert this machine back. Yourbest bet might be to find a trashed machine with a complete 78 mechanism andusing that in yours.
David Breneman david_breneman@yahoo.com