Most Popular Articles
Don't become a statistic
Broadcast engineering history includes a number of accidental deaths. By its very nature, working with high voltages, heavy equipment and tall towers, is an invitation to trouble. Since the development of radio transmission, a number of well-known (as well as many relatively unknown) engineers have unfortunately lost their lives through even such lamentable accidents as raising a field strength-measuring antenna into a power line over a measuring truck in the dark.
It used to be said that you could distinguish radio engineers by the burns on their hands and forearms, generally produced by RF when working with transmitters and antenna systems. It seems to me that RF alone was not usually solely responsible for many fatalities in our field.
There are many lists extant of precautions to take before working with high voltage pieces of equipment. Lethal incidents may be more often caused by completely unexpected circumstances than from pure, careless accidents.
More than 50 years ago I was director of engineering and general manager of CHCT-TV, Calgary, Canada. Canadian GE was supplying and installing the super turn-style antenna on our 600-foot tower about 20 miles west of Calgary. A fair number of people had gathered to watch and the RCMP was keeping the crowd at least 1,000 feet away from the base of the tower. Just before the antenna raising commenced, one of the riggers asked to ride on the antenna as it was hauled up, in case it fouled the tower or the guys. I said, “No, climb the tower in pace with the antenna.”
The winch started and the antenna began to ascend. It rose slowly and smoothly until, when at about 400 feet, a very strange sound was heard. It was a keening, flute-like note, probably around 3 to 4kHz. The winch stopped.
Suddenly the antenna began to fall! I was concerned lest it foul the guy wires or the central mounting pipe struck the tower and brought it down, too. Very quickly the bottom of the pipe struck the footing and the ground. There was a strange puff of red smoke (the red beacon glass had disintegrated upon impact and I could not find a single piece of red lens at the base of the tower) as the pipe entered the ground for about 7' and gouged the side of the footing. The pipe was bent, two antenna sections were wrecked and one damaged. The rigger who wanted to ride the antenna came down the tower looking rather white and said to me, “Thank you.”
The hoisting cable had failed due to a kink occurring the previous week when another station's antenna was being raised in Saskatchewan. Apparently no one had been concerned about this. The strange flute-like sound was that of the individual strands of the metal cable breaking at the kink. This was truly an accident waiting to happen.
Another potentially fatal accident occurred when we were tuning the transmitter of KAVE -TV, Channel 6, Carlsbad, NM. We had finished installing the transmitter and all the tubes, including a set of mercury vapor rectifiers across the open lower front of the PA cabinet, and applied power. Everything seemed to be working and I was tuning the final.
Suddenly someone hit me on the back of my neck with a baseball bat and at the same time someone else hit me in the groin with another baseball bat. I sank to the floor. There was a smell of burnt clothing and my right knee was very sore. After a moment, I got up, killed the high-voltage circuit and replaced the bottom section of the front of the PA cabinet. This prevented other careless people's knees from contacting the top caps of the 9kV mercury rectifier tubes of the high-voltage supply. I was lucky to be alive. My right hand had been on the metal cabinet and my right knee came in contact with the top cap of a 9kV power supply — good conditions for electrocution.
Acceptable Use Policy blog comments powered by Disqus
[an error occurred while processing this directive]
Today in Radio History
The history of radio broadcasting extends beyond the work of a few famous inventors.
EAS Information More on EAS
The feed provides feeds for all US states and territories.
Need a calendar for your computer desktop? Use one of ours.
Information from manufacturers and associations about industry news, products, technology and business announcements.
Browse Back Issues[an error occurred while processing this directive]
Also in the January Issue
- Trends in Technology: AES-X210, The "Missing Piece" of AES67?
- FCC Proposes Online Publc File Rules for Radio
- RF Engineering: Licensing AM Stations Using Method of Moments
- Field Report: Zoom H6