I bet the tube rectifier filament supply transformers are getting hard to find now. Rob K5UJ On Wed, Jun 8, 2011 at 8:49 PM, <edwmullin at aol.com> wrote: > My Home Brewed B+ supply has a FW Bridge with 866 tubes, I hand wound the filament transformers for it on old microwave oven cores. ?Works FB OM. ?and looks mighty nice on the peaks! >