The radio boys were at Bob's house on the dot, all but Jimmy, who to his great disgust had to do some work for his father, and so could not come.
"I suppose we'll have to try to get along someway without his valuable assistance," said Herb. "When he told me he couldn't get here this afternoon he certainly felt sore about it."
"I guess I know how he feels, all right," said Joe. "It would pretty near break his heart not to be able to work on this radio stuff now. I'm crazy for the time to come when we can pick our first message or music out of the air."
"I guess you're no more anxious for that to happen than we are," said
Bob. "Let's go downstairs and see what we can do."
They all made their way to Bob's workroom in the basement, where they found the core well dried and the wire as firmly set on it as the most particular workman could desire.
"Good enough!" exclaimed Bob, examining the core with loving pride. "We'll get this set up in a jiffy, and then we can make the condenser."
Working together, the boys soon had two square blocks sawn out as end pieces, and they centered the core on these and screwed it fast. Then they drilled holes in the two upper corners of the square end pieces to fit two brass rods they had bought at the hardware store. These rods carried each a small sliding spring, or contact, which rubbed along the length of the tuning coil, one on each side. After they had bolted the brass rods securely in place, the coil was ready for use, except that the boys had first to scrape off the insulating enamel in the path of the sliding contacts, so that they could reach the copper coils. A sharp pen knife soon effected this, and the boys found themselves possessed of a neat, substantial tuning coil, at a cost of only a fraction of what it would have been if they had had to buy a coil already made. And in addition they had the satisfaction that comes of a good job well done, which more than compensated them for the labor involved.
"That begins to look like business," exulted Joe. "We'll be putting
Mr. Edison out of business pretty soon."
"Yes, it's lucky he can't see that tuning coil," laughed Bob, "he'd be looking up the want ads in the papers, sure."
"Oh, that coil won't be a patch on the condenser we're going to make," declared Herb.