[Towertalk] Lightning Protection - Conclusion (for me, anyway)

[Tom Rauch]

>      My original query (Must I ground the coax shield ahead of the
> Polyphaser suppressor?) is one of those
> angels-dancing-on-the-head-of-a-pin kind of thing.  It'll never be
> answered objectively (quantitatively.)  So I'm going to have to be
> satisfied in knowing that I have grounded the coax shields at the top
> and bottom of the tower and I have installed suppressors on all coax
> (as well as control cables) coming from said tower.

Grounding and lead layout, IMO that is the key.

I have miles of coax and miles of wires spread over a large area, and 
the tallest tower is over 300 feet tall. The 2-meter metal dipole 
array at the top (connected to a repeater) actually has holes melted 
in its aluminum mast pipe from repeated lightning hits!

I use good single-point grounding at the towers and again at the 
house with bulk-head feedthrough connectors...and that's about all. I 
do have MOV's on power lines and telco lines at the bulkheads, so the 
power lines are clamped at several hundred volts.

Despite the total lack of arrestors of any form on feedlines, and the 
fact I never disconnect any cables (there are far too many to unhook) 
I have never had a major problem with anything from lightning here in 
middle western GA.

On occasion a feedline shield will vanish, or an antenna wire melt in 
half, but basically everything else just keeps on working. 73, Tom 
W8JI
W8JI@contesting.com