Radio gaga

I was pleased to be informed by Jack Grove’s article “Tinkering helps to dial in the joy of learning” (Campus close-up, 23 July) that Saeed Reza Taghizadeh at London Metropolitan University is convinced that, for children, building your own radio is “still a fantastic thing to do”. In my boyhood I certainly tried to construct a crystal set but was dismayed to be told that the essential “cat’s whisker” did not require a real cat. Moving on to proper wirelesses involved trips to London’s Lisle Street, where shops sold off war surplus stuff for keen radio hams. I only managed to build a set that glowed and emitted a constant low-pitched noise known technically as “mains hum”. Nevertheless, visits to Lisle Street in Soho proved to be highly educational.

R. E. Rawles
Honorary research fellow in psychology
University College London