[hsusmann]

OK, so if you touch the grid cap to the RF amp (#78 ) does it
also bring in the signal?

If the answer is yes then the problem is somewhere between
the grid of the 78 and the antenna terminal

If the answer is no then the problem is somewhere between
the 78 tube and the 6A7 grid.

Could be any number of things, open coil being one of
the possibilities. Could also be a missing or broken wire,
a bad connection, a bad capacitor, to name a few.

You're going to just have to start eliminating possibilities
one at a time

Herb