"The second anode takes about two hundred volts worth of eighty-four cycles," explained Barney. "Has a sign that seems to signify 'In Phase,' but I'll be darned if I know with what. Y'know, Jim, this dingbat looks an awful lot like one of the drivers we use in our spaceships and driver-wing fliers."

"Yeah," drawled Jim. "About the same recognition as the difference between Edison's first electric light and a twelve-element, electron multiplier, power output tube. Similarity: They both have cathodes."

"Edison didn't have a cathode—"

"Sure he did. Just because he didn't hang a plate inside of the bottle doesn't stop the filament from being a cathode."

Barney snorted. "A monode, hey?"

"Precisely. After which come diodes, triodes, tetrodes, pentodes, hexodes, heptodes—"

"—and the men in the white coats. How's your patching job?"

"Fine. How's your power-supply job?"

"Good enough," said Barney. "This eighty-four cycles is not going to be a sine wave at two hundred volts; the power stage of the BFO overloads just enough to bring in a bit of second harmonic."

"A beat-frequency-oscillator was never made to run at that level," complained Jim Baler. "At least, not this one. She'll tick on a bit of second, I think."

"Are we ready for the great experiment?"

"Yup, and I still wish I knew what the thing was for. Go ahead, Barney. Crack the big switch!"

Altas held up a restraining hand as Than grasped the main power switch. "Wait," he said. "Does one stand in his sky flier and leave the ground at full velocity? Or does one start an internal combustion engine at full speed?"

"No," said the youngster. "We usually take it slowly."

"And like the others, we must tune our tube. And that we cannot do under full power. Advance your power lever one-tenth step and we'll adjust the deflection anodes."

"I'll get the equipment," said Than. "I forgot that part."

"Never mind the 

 Prev. P 7/26 next