Good call E M
This set uses a FBT winding so at 15Kc's. They did make brightener /
isolation in the day,, just use the right kind.
2 tricks for basket cases.
1) there is almost always a one or two ohm resistor in series with the F.
Just jump it out, it will bring the F up to abt 8 V
2) On older sets with an open FBT core you can add one turn to
the F in series. This should be done with a scope so you dont
go too far.
73 Zeno
LFOD !