[AI2V]

In the Philco Restoration Notebook, its recommended to replace the finicky 36 tube osc/mixer with a 6A7 tube; that requires a substantial amount of rewiring and alterations of the coil.

I've found it much quicker to simply replace the 36 with a 6SJ7 (or 6J7 if you want to keep a glass tube). Using the 6SJ7 requires nothing more than a tube socket change to octal and to bring the grid connection to the base of the socket. No further wiring changes are needed. Using a 6J7 will allow you to keep the grid connection on the top of the tube and requires a tube shield.