[radio1]

Looking at it,  there are many different schemes utilizing the field coils in these old radios. It leads me to questions of how they used it. In this case you could substitute resistors for the field coil. In looking at the Philco 70 circuit, replacing the coil with only resistors (which is what I have at the moment), it would seem the screen before the plate (supplied by the coil) would allow the rf ac, from grid to plate, to ride the DC right back into the output transformer, so I wonder this, does the the field coil stop this ac(rf) from entering the output transformer (other sections from which it is intertwined? Very perplexing to me. In substituting just resistors, does it require a choke also? I put the scope on it and saw this DC rail ride the RF back to the output transformer when using resistors and not field coil, does the field coil block screen rf on the dc rail?