"Have you tried any kind of tube amplification?" asked Don.
"Not yet. Shall we?"
"Why not? I can still think that the relay tube will amplify if we hook up the input and output loads correctly."
"I've got a tube already hooked up," said Walt. "It's mounted in a panel with the proper voltage supplies and so on. If your resistance calculation is correct, we should get about three thousand times amplification out of it."
He left, and returned in a few minutes with the tube. They busied themselves with the connections, and then Don applied the power.
Nothing happened.
"Run a line from the output back through a voltage-dividing circuit to the in-phase anode," suggested Walt.
"How much?"
"Put a potentiometer in it so we can vary the amount of voltage. After all, Barney Carroll said that the application of voltage in phase with the transmitted power is necessary to the operation of the relay tube. In transmission of D. C., it is necessary to jack up the in-phase anode with a bit of D. C. That's in-phase with a vengeance!"
"What you're thinking is that whatever this sub-level energy is, some of it should be applied to the in-phase anode?"