Saturday, August 04, 2007


Back in 1971 when I built my first topband rig I needed to power it, so I built from scratch, a nice 300 volt PSU on a shiny new aluminium chassis. BY100 rectifier diodes bought from a rally (which were leaky!) and smoothing capacitors which came from TV sets. I built this up with two ot three 16 microfarad capacitors lined up like missiles on the chassis. The PSU was 'hummy' to say the least, but it powered the transmitter! friend Paul came to my shack to see my new transmitter...

"CQ, CQ, CQ, ....Oh...the PA meter is not reading right"

"CQ, CQ ...what's happening...the inputs dropping...look Paul"

"I'll try again....CQ, CQ ... watch's going down!"


A capacitor bounced from the ceiling and the floor and the shack half filled with disgusting, pungent, oily, waxy white fumes! My ears rang and when I looked round mine and Paul's head and shoulders were above the smoke and everything else was submerged in white smoke! The marks of this catastrophy can still be seen in what is now the garage at my brother's house, the dint in the roof.So what was the cause of this?Remember the 16 microfarad capacitors? They were only rated at 250 volt and my transformer was pumping out near 350 volt into leaky rectifiers! Never again!

The chassis was a mess, buckled and covered in sticky wax and paper, thing is, the explosion went downwards as well which messed up my bench. Bit's of waxy paper could be found for the next few weeks in places you would not imagine!er...Paul didn't come back after that!

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