Maybe the pin 4 thing was good practice, remember that the UL41 valve was a relatively new kid on the block at that time and that it had a fairly high value of mutual conductance, the valve manufacturer recommended that a grid stopper when fitted should be connected as close to the valve as possible which to me implies that it should also be located as close to the valve as possible (which it was) There would have been enough room on that corner tag of the tag strip to connect it to along with the coupling capacitor and the grid return resistor if required, so maybe not a bean counting exercise but actually good design practice at that time for a valve that has a high mutual conductance....
Lawrence.
Lawrence.
