Sherlock Ohms: The Case of the Earth Station Stopped by Lightning |
 This
is another great RF troubleshooting saga; in fact, it would make a good
short action film. Designing and implementing proper lightning
protection can be a real challenge - and quite expensive. Lightning
has a nasty habit of seeking out and exploiting weaknesses. Author Rod
Hine doesn't cite improper protection as the culprit for causing his
woes in his telling of, The Case of the "Earth
Station Stopped by Lightning." A couple decades ago I worked with
a team that designed a prototype weather radar system with cobbled-together
parts that included a surplus military phased array antenna. After doing
all the initial design, build and test at our facility, everything was
moved to an open air site that sat at the top of a ridge which was known
to attract lightning like trailer parks attract tornadoes. A fair amount
of effort went into lightning mitigation over the years, so we felt
comfortable hooking into the existing system. All went fine for the
remaining time I was there. About a year later I was talking to an engineer
I had worked with and he said that the system rack had taken a major
lightning strike and had to be totally rebuilt. After immediately being
thankful that I wasn't there to experience the disaster, I was
told that the reason it happened was because the guy who plowed the
site had disconnected a heavy copper ground cable that fed the antenna
and rack to get the plow through, then forgot to reconnect it.
At least that is the story I was told... but I'll deny it in court.
Posted August 21, 2013 |