I think the definition of 'single point' can be a little tighter than it may
appear:
My remote station is at a former AM broadcast tower - so that is very well
grounded indeed. I also have an APRS digi on the tower (antenna at 260' on a
325' tower). The coax comes down the tower and through a surge suppressor where
it enters the hut. The AC feed is underground for about 500' and is grounded to
the tower ground at the service panel though wide copper strap. There is about
10' of cable between the service panel and the outlets for the APRS digi and
TNC power supplies. A month or two back there must have been a lightning strike
on the tower - I found that the digi and TNC power supply transformers had been
destroyed - the fuses had clearly blown very forcefully. The radio and TNC, as
well as all of the remote station equipment, were totally unharmed.
I can only assume that that 10' of power cable was too much and allowed a large
potential between that and the antenna cable. Either that, or the power company
found a way to put DC on the AC line!
73 Roger
VE3ZI
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