Last week, we had a T-storm with one lightning bolt hitting about 100 yards
away. To my surprise, there seems to be very little damage from electricity
surges coming through the AC mains. Instead, it seems to have traveled
along using the CATV coaxial cable, perhaps on the cable shield. In our
house, we lost two cable boxes (out of four installed and operational) ant
the TVs associated with them. The TVs would actually turn on but there was
no picture, indicating the damage was probably done to the TV's front end.
The internet/CATV and phone service were out for several hours. I lost my
ham PC, irrigation system controller, RS-232/USB adapter and I/O board for
the K3 and a Winkeyer. No indication that anything came in through the AC
mains. The same story was true for pretty much all of the 5-6 houses that
were in the immediate area of the lightning strike, i.e. TVs and cable boxes
were blown (but not all of them in a house) and a few other things but very
little damage coming in through the AC mains.
I think this indicates that the AC ground was pretty good for the houses in
the area. On the other side, it would seem that the ground on the cable
system leaves a lot to be desired. We can improve our AC ground, as many of
us have done, but I don't think we can do much about the cable systems
grounding. Anyone had experience with this situation and, if so, how did
you get it fixed and protect yourself from future such events?
Tnx, 73,
Dennis, K2SX (temporarily QRT)
_______________________________________________
CQ-Contest mailing list
CQ-Contest@contesting.com
http://lists.contesting.com/mailman/listinfo/cq-contest
|