US "tubes" = UK "valves".
Shortly after the war my dad trained as a radio fitter in the RAF, repairing valve radios in aeroplanes. Transmitters were larger tham modern microwaves, and had to warm up before use, or risk damage. A great treat I had once was clambering round inside an Avro Shackleton with my dad one evening while he repared something, with dire warnings of "DO NOT TOUCH ANYTHING" ringing in my ears. I was probably allowed in the evening because the officers would be off duty by then.
I remember as a kid he spent his evenings repairing valve TV's for rich people. Ordinary people like us could not afford them, but we got to watch other people's TV sets because he had to test them after repair. We got maybe three evenings free TV from each one. I wonder if we had a TV licence? ( Probably not! )
My modern set is probably only 2 inches front to back, but these old sets were huge. I was able to crawl inside the empty case of one! When we turned them off, the picture would shrink into a small dot which would glow in the centre of the screen for a while. I recall as a small child sometimes staring at the dot with my eyeball right up to it, wondering where the little people had all gone...
During my own RAF service I recall being told that Russian aircraft still used valve electronics rather than transistors, because they were more resistant to EMP from nuclear explosions. I was also told that the valve radars in the nose of some Russian aircraft were powerful enough to cook rabbits some distance in front of the nose of the aircraft. I took the last with some salt, not being sure if they were just testing the credulity of a newcomer.
Oh, and it is a lovely token. Thanks for sharing.
Edited by Anaximander
01/29/2018 5:22 pm