What type of pot core and winding?
the primaries were driven in parallel and the secondaries were connected in series–all phased correctly. This was done as a quick & dirty way of achieving a “step up” and allow for enough power–before core saturation. The specific pot core specs are only important relative to optimum operating frequency: ~10 kHz to ~40 Khz, peaking at ~ 20 kHz. However, this is not critical due to the broadband nature of ferrite transformers. One could use alternate transformer technology: a single large ferrite torrid.
