[TowerTalk] Grounding an Insulated Tower (more)

[Richard L. King]

I have gotten some pretty good advice here so far. Thanks to everyone 
for that. But I have some follow-up questions.

What is the best thing to use for a spark gap? I read there are ball 
types and pointed types and I am not sure what is best. I know that 
if you use a in-line pointed type, you need a drip shield. What else 
should I know about this?

Where can I find commercial products that I can buy to use? Or must 
it all be home-made? Any URLs?

If I build an inductor to place between to upper (insulated) part of 
the tower to the bottom part of the tower, what inductance should it 
be to not effect the 160M operation?

What are the popular common mode chokes to buy for use at 160M? Or is 
there information somewhere for making your own.

I know I am asking a lot of questions that I eventually research and 
figure out for my self. But the insulated tower project here was 
completed yesterday and I am in a rush to get lightning protection 
installed before the next lightning storm. In Texas, we are subject 
to big lightning storms years around.

Thanks.

Richard - K5NA



At 13:09 1/6/2008, Richard L. King wrote:
>Hi everyone. HNY.
>
>I am near completion of a 155 foot 25G tower with an insulator 30 
>feet above ground to use on 160M. I am interested in techniques for 
>grounding for lightning protection and to bleed off noise from rain 
>static, etc.
>
>The tower will be fed directly with the coax to the upper insulated 
>part and the coax shield will be connected to several raised 
>radials. The coax and the radials will NOT be connected to earth 
>ground at the tower.
>
>I am worried that a direct lightning hit might cause me sever 
>problems if I cannot bleed it off somehow. I have thought about 
>lightning spark gaps and maybe a large inductor between the 
>insulated section and the lower part of the tower, but not sure how 
>that will work and what should be the values of those components.
>
>I do plan to ground the lower, unattached, section of the tower with 
>ground rods.
>
>Thanks.
>
>73, Richard - K5NA