[kalee20]

I've played with chemistry, too - nitrogen tri-iodide is interesting stuff. I read that a single alpha particle is enough to trigger decomposition. But I've only made fractions of a gram - I value my hearing! I did have the sense (just), make a small amount of any explosive mixture first, assess it, before larger quantities.

Moving on from chemistry (the link to 'this hobby' in the thread title is rather tenuous after all), I played with electroplating copper in primary school. Batteries, bulbs, small motors and buzzers were great fun. I had a large electric bell which had a hold-off latch which held the contacts apart, so zero power. But an auxiliary contact bypassed the main to energise the electromagnets, pulling the armature and releasing the latch, after which normal operation commenced. I connected this to my clockwork alarm clock, so that when the alarm went off, the rotating wind-up key touched a carefully-positioned wire, triggering the bell. It was great!

I had a small electronics kit given to me (Denshi), with several resistors, a few capacitors, two transistors, all in plug-in modules which fitted into a baseboard. There was a booklet with 30 projects to make, different radio circuits (I found the reflex circuit the best).

I had my first mains radio given to me when I was 11, by a priest at chatechism class. It was a Ferguson 208U, 3-band, AC/DC. I learned a lot from this and I had much fun. I also took chances I didn't really know about - fitting an extension speaker socket was one of the first things I did, good job the insulation in the output transformer didn't let me down, especially when I used this to feed my father's tape recorder!

The Denshi-kit had a wireless microphone circuit, which I made, this was one of the few which didn't work particularly well. I tried earthing the circuit, using a mains plug's earth pin pushed straight into the socket, which gave a small improvement. I did wonder if coupling to the Ferguson would be improved with a direct connection, so touched the wireless microphone aerial lead to the Ferguson chassis... BANG!! Molten copper shot from the Denshi kit RF coil, out went the Ferguson's light, chastened me... How to learn about live chassis sets plugged in the 'wrong way round!' The Ferguson needed only a replacement panel light (the bypass thermistor was blown to smithereens but that didn't matter), but the Denshi Kit transistors never works again.

And so, through the years, some mains shocks along the way (but never any TV EHT, to this day), the obligatory exploding electrolytics, the firework detonators, the sparks from car ignition coils, the amplifiers designed and built from old TV components, through to a working life in electronics right through to lunchtime today! Now back to the 'Day Job,' which is to debug a 200V piezo transducer drive system!