At 05:43 AM 8/2/2005, Tom Rauch wrote:
>....You not only had a very poor tower ground, it sounds like
>the entrance panel was never bonded to the power mains
>entrance ground! If we don't bond the entrance panel to the
>utility ground it is a big problem (and goes against the
>national electric code).
>As you painfully found out, ground rods do next to nothing
>for establishing a good ground. A poorly grounded radio
>entrance panel that isn't bonded to the utility entrance is
>also a big problem.
OK - Question. My aluminum entrance panel is in a second-floor
window. The hardline (CATV) comes out of the ground (conduit) alongside
the house, and flexible coax runs from there across a porch roof, maybe 50
feet to the shack window. Where the hardline comes out of the conduit, I
have grounded the shield to the same ground rod as the AC service.
I disconnect everything at the entry panel but don't usually disconnect
equipment from the house AC. With close hits I have had three instances
when I have had arcs from the center conductor of the barrels in the entry
panel to the shell, and thence to ground -- it's pretty startling, but
aside from a little soot, no visible damage.
Two years ago I took a hit on the top of my tower, about 200 feet from the
house. No radio gear was damaged. I lost 2 computers and a phone
answering machine due (I think) to induced voltage on the house Ethernet
wiring, and of course everything electrical on the tower proper (2
rotators, an RCS-4V and a Stackmatch).
Have I done about all I can, given my compromise shack location? Would it
make sense to plug grounding plugs into the barrel connectors, to "assist"
the strike voltage in finding its way to ground?
73, Pete N4ZR
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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