[wtoeller]

Rob - you are correct. There are no other 150 ohm resistors in the schematic besides the cathode bias resistor. I currently have 6 of these radios and they all have this 'extra' 150 ohm resistor where I indicated! I can only speculate that it was a mid-stream manufacturing change that did not get into the schematic, or, the schematic I have is an earlier (or later) version then what my radios have.

Someone smarter than me will have to deduce why this design was implemented.