The 11-year-old has been bugging me for a few years now that he wants to build a crystal radio set, and sourcing the parts individually is something of a pain. So when I saw a kit for cheap at a surplus site, I thought: Cool!
Perhaps not. After a couple of tries we got the antenna wire wound onto the cardboard tube (barely — about half an inch so spare on each side when all the turns are solidly butted against each other) only to find that the holes in the molded, foldable plastic sheet that serves as the frame aren’t quite big enough for the tube.
Sorted that. Turns out the tabs that are supposed to lock the frame together when you fold the sides up, don’t. Sorted that too.
Then the 11-year-old, who had been doing pretty well with the instructions, asked me to interpret a paragraph that apparently referred to the two pieces of extra wire in the kit, one of them as “the second wire” and the other as “the other wire”. We duly hooked them up to the places specified. After spending several minutes with the wire stripper trying to find that tiny little thread of metal inside the tough rubber insulator.
Nothing. Nada. Less than the crackling we got just touching the earphone wires to metal objects.
So the kid went back to playing retro video games while I reread the instructions and looked at the circuit to figure out what it thought it did. Turns out “second wire” and “other wire” are synonyms. Time to undo and redo some tiny bolts and washers. Then I read further in the little booklet and found the instructions for connecting one wire to a cold water tap (because we live in a parallel universe where no one invented PEX or nylon and so all water taps are connected to ground) and then holding the other wire in your hand while with your other hands you hold the kit and move the little tuning ball across the antenna.
Did that, actually got some 60-cycle hum. It’s a beginning, and the kid was not entirely disappointed.