He reached out
>and grabed the boom and "ZAP" he was hit with a static discharge that could
>be heard on the ground. It made his hand and fingers numb for a few
>seconds, and surprised the heck out of all of us.
>LESSON: When sliding an antenna up a long parallel run of nylon rope,
>discharge it with a grounding wire before touching it.
>LESSON 2: When working at 92' never assume anything. Check and double check
>everything, the thing you least expect will jump up and bite you.
Mick, those of us out here in dry climates are very aware of the "potential"
for creating large potentials as you describe.
I once was removing a balun from a large, wire, log-periodic array used
for ionospheric sounding. Probably a total of 15,000 ft of wire in the
1.6-40 MHz antenna. I knew that once I removed the balun the wire
would be ungrounded and I had to be very careful to stay away from
it. It was a beautiful spring morning with only the lightest of breezes
but that was enough to create a charge that did NOT wait for me to touch
the antenna--it just reached out and grabbed me and knock me to the
ground, even though I was wearing rubber soled shoes.
I have done a few antenna installations with helicopters and the
static created by the down-draft prop-wash is spectacular. You
ALWAYS wait for the pilot to touch to dangling cable from the
antenna that he is carrying to the tower before you grab anything
associated with the helicopter part of the circuit. To do otherwise
can dramatically increase your laundry duties for the week!
Climbing a 300ft tower on a perfectly calm day can be a real
enlightning experience. Not a cloud in the sky and not a hint
of a breeze but a continuous corona of electrical discharge more
than a foot long coming off the top of the lightning rod. I treated
it like a venomous snake!
Glad the only casualty was the underware.
73 John W0UN
FAQ on WWW: http://www.contesting.com/towertalkfaq.html
Administrative requests: towertalk-REQUEST@contesting.com
Sponsored by Akorn Access, Inc & KM9P