[radiograham]

Hello all,1950s home built tv circuits are mostly trf designs for simplicity,i wondered if anyone knows of a s/het design that gives constructional details of the if transformers,i am trying to reconstruct the rf deck in a philco bt1840 which i tried to convert to 625 lines years ago,the original coils are long gone i'm afraid.the original if frequencys were vision 13mhertz sound 10mhertz,i have a lot of 1950s p/television mags but have'nt come across anything yet. Graham.