Warning! Caution when handling electrical equipment!

A Shocking Tale

by Adam M. Farson, VA7OJ/AB4OJ

I have a hair-raising personal experience to share with you. It brought into sharp focus that well-known caution:

Switch to Safety!

In 1968, whilst working as an RF engineer at the CERN nuclear research centre in Geneva (Switzerland), I got my hand in the 1.4 kV screen supply of a 4CW10,000A. I had done all the wrong things; I was working late, alone, in the RF lab, doing output impedance measurements on a 10 kW 10 MHz amplifier for a particle accelerator.

I was holding the earthed probe of an HP vector impedance meter in my left hand, and reached down with my right hand to press the start button on the HV power panel. Carelessly, I missed the button, and stuck my hand in the live terminal block. I am grateful to Providence that it was only the screen supply; had it been the 5 kV anode supply, my goose would have been cooked - and I with it! I was not even an active amateur at the time.

The resulting shock threw me across the lab, and left me with small scars on both hands.  I still recall that when I got up off the lab floor, 5m away from the beast which had just bitten me, I shook myself off and somehow made my way to the cafeteria (which was open 24/7). I sat down at the bar, and the barman looked at me and said: “Monsieur, you look like death warmed up!” That made me feel just great. I recounted the incident, and the barman grinned at me. “Monsieur, double Courvoisier on the house! I don’t want you dying on me!”

The drink was just what the doctor ordered. It enabled me to face the grilling and the 10mm stack of paperwork which awaited me at the “Sécurité du Travail” (Worksafe) the following morning.

The long-term consequences of all this are a mortal fear of high voltages and a determination that I will never own a tube-type amplifier. Since returning to the HF bands in 1989, I have only run an all-solid-state station; at first 500W, later 1kW (since 1998). I feel relatively safe now. Besides, I am extremely careful working around exposed live equipment.

Copyright © 2007-2015 A. Farson. All rights reserved. Last updated: 29/02/2016