Timothy Daniels wrote:

"Michael A. Terrell" wrote:

All I know is that I finally kill filed him on this computer after I got
tired of reading his 'twilight zone' electrical & electronics babble.
I am a former radio & TV broadcast engineer, and if I followed
his or _wacko_tom's warped ideas, I would have had millions of
dollars worth of damage. I had a studio building and STL tower
in Leesburg Florida hit by a direct strike. It blew chunks of concrete
from the building where the rebar and threaded rods ran vertical.
It WAS an excellent example of _wacko_tom's UFER ground,
before the steel vaporized inside damp concrete. 95% of the damage
was caused by the EMP.

[ElectoMagnetic Pulse]

I lost the 11 GHz Cars band STL, the 1A2 type phone system,
all the computer terminals, and had some minor problems with
other electronics. It turned out that the dead terminals all had high
ESR electrolytics,

[Equivalent Series Resistance - the total of all internal resistances
of a capacitor measured in Ohms.]

and that they were working because they were all on UPS

[Uninterruptible Power Supply]

before the strike took out all the electricity. The power 1A2 supply
needed some of the weird WE fuses, one KTU card and was back
in service. The STL

[Studio-to-Transmitter Link (see http://www.fmamtv.com/rdstl.html)]

was mounted on the tower in a steel NEMA box, and lost the LO

[Local Oscillator]

module. It was 20 years old, and at least 10 years obsolete, so it
needed that module updated, anyway.

I started with the phones, then arranged a twice a day courier form
the studio to the transmitter site with U-matic tapes. We rented a
STL transmitter and shipped the damaged system to the OEM for
repair & upgrading. The terminals were down for a day, while I
waited for the new electrolytics. Or viewers didn't even know we
had been hit. Then I moved the microwave racks to a closet in the
corner of the building, and used 4" EMT

[Electrical Metallic Tubing, i.e. metal conduit]

between the rack and the tower. That was 20 years ago. They
have had strikes since then, but no problems.

Would you please sum up what you believe to be prudent
protection (for electronic equipment) from nearby lightning strikes?
I'm thinking of both in single-family homes and in condo/apartment
buildings. What would you do to protect from in-house (or in-building)
surges, such as elevator motors suddenly shorting out, or welding
equipment in use?


The same thing we did in the studios and transmitter sites. Use a
combination of protection at the building's main disconnect, and
individual protection at each critical device. The only thing that I've
lost in the last ten years was when lightning hit a huge pine tree, and
cut the top half of it off. It landed on the ground right over the
buried telephone line, and a second strike blew out the modem and MOV
protection on the phone line. It also destroyed that underground phone
line. The replacement is in 1" PVC conduit to make it easier to
replace, just in case. I live right on the edge of a protected green
belt, in north central Florida. The tallest of those trees would fall a
couple feet from my house.

I lost power from that strike, but no other electronics.


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