One hundred years ago, in the November 1925 issue of Boys’ Life, radio editor Zeh Bouck apparently realized that many scouts already owned a crystal set, and were thinking of upgrading by adding a “bulb”. His column details two methods of doing exactly that. First, he discusses how to replace the crystal detector with a tube, and notes that this option is somewhat less expensive. However, his preference is the second method, namely, keeping the crystal detector as-is and adding one tube as an audio amplifier.  Parts lists are included, and the first method, replacing the detector, would set the scout back $5.80. Adding an audio amplifier would require a transformer, which could cost an additional $1.50 to $5.

He assures that both methods are just about as easy as the A, B, C’s, and he gives detailed instructions.