[radiomikee]

I relate this story because it has happened to me before, it is not always easy to notice, and can have serious consequences. I had just finished recapping a 16B chassis, one which I am very familiar with. All the tubes were checked and ready to go. It warmed up fine, but the set seemed not working right, there was some clicking type audio when changing bands, and tlow volume only when touching the second detector, but I got no IF through. A quick voltage survey showed absent voltage on the screen grid of the 77 first AF tube and plate of the 78 QAVC tube. Tracing the feeder to that point, I found the wire which runs from the 1 MEG resistor on the 5th terminal of the filter bank can had been caught under a bakelite block (compressed between the foot of the block and the chassis). After shutting down and extricating it, I could see that the insulation was crushed and the wire had shorted to the chassis!! After freeing it, the radio played like a songbird. If I had not picked up on this for a while, the power transformer may have been at risk. This was my second experience with a similar fault. Another clue was that the 80 rectifier tube had blinked briefly, with a strange light flash inside it, the first time I full powered the chassis, probably as the short developed. So one can never dodge mistakes entirely, and some of them are of our own making!