In message "Chris" wrote: > Did you see the phasing dots on the schematic? Can you tell us more about > how you tried to wind the xformer and what type of core you are using? I'm using a 2-pin ferrite "drum" - a similar same type as the one shown on the webpage. I put some double-sided tape on the ferrite, wound 35 turns of wire on clockwise, made a center-tap, added another layer of d/s tape, then wound another 35 turns on anticlockwise. I've wound simple (single-coil) inductors before, but not this sort of thing... Later. -- Phil. | Acorn Risc PC600 Mk3, SA202, 64MB, 6GB, philpem@philpem.me.uk | ViewFinder, 10BaseT Ethernet, 2-slice, http://www.philpem.me.uk/ | 48xCD, ARCINv6c IDE, SCSI ... Once you understand your computer it is obsolete -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist