'I was amazed that, at 15, I knew Ohm's law'

"Wanted: someone interested in radio." I was 15 when I saw the ad in the Berkshire Chronicle. I was very keen on making amplifiers and radio sets, so I applied; I received a letter on BBC paper and went for an interview.

The engineer-in-charge was so amazed that I had heard of Ohm's law – "E over I = R, E over R = I, and E = IR" – that I got the job. In 1941, the BBC was setting up local, low-powered transmitters that were switched off if there was an air raid so they couldn't be used by German planes to navigate. As a "youth in training", my job was to switch the transmitter on in the mornings and off at night, and to check that it, and the feeder land lines, were working.

After the war, I went to the BBC monitoring service in Caversham, a suburb of Reading. It was a big aerial system to listen to radio programmes all over the world. In 1956, they asked for volunteers to transfer to other BBC departments. I said I wanted to go into television, and I was in the Lime Grove studios the next day.

It was very exciting, a wonderful job. Television was all live – there was no recording. In those days, the cameras were heavy and you had to drag the cable behind them and get the other cables out of the way. It wasn't long before I was a senior cameraman. You had to pan the camera from side to side with the left hand, and focus with the right hand. Somebody else was "driving" the motorised dolly. If things hadn't gone well on the Sunday play, say, you dreaded when the play was going to be repeated – again, live – on Thursday. The other crew members used to watch the back of your neck, to see if it was going red.

I was in on the first edition of Blue Peter, and of The Sky at Night, when the producer came down to ruffle Patrick Moore's hair: "It would be better if you look slightly wild." I was behind the camera for a children's programme presented by Huw Wheldon [later presenter of the arts series Monitor] when he did an interview about pets with a boy who brought along his mouse and his eagle. Wheldon remarked how interesting it was that these two, mortal enemies in the wild, were getting on like a house on fire. At which point, the eagle ate the mouse.

Wheldon also once interviewed a small boy who had built a full-sized working harpsichord entirely out of matchsticks. Wheldon asked him, "What are you going to make next?". He then placed one hand rather heavily on the instrument and there was an ominous crunching noise. "Another harpsichord," came the sad reply.

'Paddington Here and Now' by Michael Bond (HarperCollins, £10.99) is out now