🙂 @Harry, do you see what you commented there? Do you think it is going to take @Bookwyrm 8 years to solve 10B Umm??? 😉 I know, I know.
When I was at that age I had just started being interested in electronics – 4 years later I built a TRF radio of my own design that won me a school prize.
Such happy times and memorys of my pre-teen age.