[Towertalk] Lightning Protection...roof tripods this time

[Pete Smith]

At 11:35 AM 12/13/02 -0600, Tony Casciato, AI9X wrote:
>I appreciate all the research/hard-work/advice that the tower owners have -
>and someday I will have one or more (next QTH) myself. For a small TH2 beam
>at 26', is this enough protection - or too much? I think that most tripod TV
>antennas don't have near this much planning...but its my house!!


For whatever this is worth, I continue to believe that the best lightning 
protection an amateur station can have is to disconnect all conductors 
coming from the tower when the station is not in use.  Our shacks are often 
compromises as to location, and are almost never totally correct and fully 
worked-out with respect to single-point grounding (SPG), etc.  In my case, 
my shack is on the second floor, meaning that my ground line is 30-odd feet 
long and contains several right-angle bends.  What is the likelihood that 
this inductive ground will hold the shack ground at ground potential during 
a direct strike?  Essentially nil.  It's been argued that doesn't matter as 
long as all your equipment is properly grounded to the SPG, because the 
equipment grounds will rise and fall together.  Maybe so, but how can you 
be sure you have achieved that precarious ideal?  We don't need to be 
connected 24/7, so why do it?

I'm knocking wood as I say this, but my station's 104-foot tower has held 
up through 7 thunderstorm seasons so far, and many cloud-to-ground strikes 
within 1000 feet, with no special measures except good tower grounding and 
disconnecting all cables at the bulkhead going into the house.  Maybe it's 
just luck, but ...

73, Pete N4ZR
Sometimes a tower is just a tower