[Reece]

Hey, my head hurts. I looked and looked at that and then it hit me between the eyes. For that radio/phono switch, imagine that you are looking down on the terminals of an old double-pole double-throw porcelain-based Frankenstein knife switch. The two terminals in the middle are the knives which move in unison either up or down. For clarity (or so the Philco draftsman thought by not drawing the complicated wiring) terminal "G" connects to point "G" at the cathode of the third 27 tube from the right. "H" connects to "H" at the grid of the second 27 tube from the right. There is a diagonal connection from the lower left "G" terminal on the switch to the upper right.

When you throw the switch "down," the left-hand knife connects to "G" and the right-hand knife connects to "H." This is the "Phono" position.

When you throw the switch "up," the radio circuit is completed by the left-hand knife and the right-hand knife shorts out the pickup probably to avoid any stray hum pickup. This is the "Radio" position.