Electricity experiment Hiss… crackle… pop

Two schoolboys play with an electronics kit. The instructions contain a warning. What will the boys do?

I’m with my friend Marc, we’re playing together. Marc and I are in the same class at school. I can’t remember the year exactly; it must be 1979 or 1980, we’re in year four or five. Playing with Marc is always an adventure. We set up secret organisations, invent signs and code words. Once we even try to make poison out of cherry stones because Marc has heard somewhere that cherry stones contain prussic acid.

Marc has an old electronics kit that probably once belonged to his father. Out of wires, resistors, transistors and lots of other components, you can construct all kinds of things: a doorbell, for instance, various light circuits or a Morse code machine. The booklet that comes with the kit contains detailed instructions, diagrams, descriptions and explanations. We’ve played with the kit before. On this particular day, Marc's parents are out and we have something special up our sleeves.

One of the instructions in the booklet describes how to make a radio transmitter. The instructions contain a warning: operating a radio station without a licence is prohibited in Germany. Needless to say, we don't have a licence. – But we build the transmitter nonetheless. We put together the necessary components, and we soon realise it’s a lot more difficult than the other experiments we’ve tried. Eventually, we’re sure we’ve assembled everything correctly. We insert the batteries, the electric circuit is closed.

In the kitchen, there’s a radio; we turn it on. Marc goes into the living room and speaks into our transmitter’s microphone while I turn the knob on the kitchen radio to adjust the frequencies. I hear hissing, crackling, popping, whistling, occasionally an actual station. But through the radio I hear nothing from Marc – all I can hear is the sound of him cursing into the microphone in the living room across the hall.

I go through the entire frequency range again, this time much more slowly. Shhhhhhtttt. – What was that? I turn the knob back very carefully. Bbzzzz. Isn't this hissing and crackling different to the sound of the other frequencies? Doesn't it match Marc’s speech rhythm as he continues to recite swear words across the hallway? I listen very carefully: Shhhhttt - - - Ffffffckkkk.