For sending up to 500 miles, the boys knew they could use either three or four 5-watt oscillator tubes in parallel, or one 50-watt oscillator tube. They had decided on the latter method, in making their preparations for departure in faraway Seattle. For one thing, and the biggest, transportation was the most important item. And the 50-watt tube set was the more compact. Quickly, then, with Mr. Hampton helping, they got out the various parts from their baggage and made the connections.
Farnum, the Northwest policeman, MacDonald, and Dick and Art, watched with puzzled interest and even awe as the four, working in unison, put together the aerial series condenser, the blocking condenser, the grid condenser, the telegraph key, the chopper, the choke coil in the key circuit, the filament volt-meter, the protective condenser in the power circuit, the storage battery and the motor generator.
Farnum and MacDonald asked questions, although Dick and Art were content to sit silent and watch, keen-eyed, as the construction work progressed. Several times, too, Dick arose and went to the water’s edge to keep watch against surprise. That any would be attempted for the time being, nobody believed, as they figured the enemy would consider them on guard.
As they worked, Jack explained for the benefit of the others. His description of how the low voltage current from the storage battery flowed into one of the windings of the generator and drives it as a motor thus generating higher voltage in the other winding both puzzled and interested them. By the time, the set was ready for use, Farnum, who was something of a mechanic by inclination, had a fair understanding of the set, but MacDonald, though interested, was bewildered.
“I’m fair beat,” he confessed. “Anyhow, just so you boys can make it work!”
“Oh, we’ll make it work, all right,” Frank assured him. “Well, now, to try to call the Post. What’s its call, Mr. MacDonald?”
“I happen to remember,” said MacDonald. “We were all so interested when wireless was put in that Captain Jameson gave us a little lecture on it. He said our call would be JSN, abbreviation for his name. We were to remember it, in case of need, when we were able to get to a wireless station. Well, this is a case of need.”
“I’ll say it is,” said big Bob. “Well, come on, fellows, who’s going to call?”
It was an honor or distinction that each was eager to have, yet each wanted to force it on the others. A friendly argument developed, to which Mr. Hampton, smiling, put an end.
“Look here, boys, we are wasting time. Suppose you draw straws for the privilege. You all know the Morse and Continental codes, so there is no question of ability involved. Here—” breaking three matchsticks into varying lengths and offering them—“take your choice. Longest wins.”