Hi Guy,
You got my curiosity up. So, there are 6 radials out of the 60 that I know
where they end. I dragged out the VOM and a long lead (100') to check.
Everything checked okay on those 6. No visible damage where the radials
attach to a 3/4" hard Cu tubing square that is attached to the concrete
pier. The Cu tubing is attached to each leg of the tower.
In addition from each tower leg I have solid #4 Cu going to 8' ground rods
that are 3' from the concrete. The wire continue away from the tower in
these three directions with a ground rod each additional 16' for a total of
4 ground rods for each tower leg. One of the wires that points towards the
house continues for another 40' where it "T's" to a box mounted on the side
of my shed that houses the receive antenna stuff (3' x 3' aluminum plate,
coax switch, preamp, common-mode choke). The ground wire continues to the
large aluminum panel just inside my basement where I have mounted lightning
protection devices for every coax and control wire plus a coax switch. From
the ground attach point of the panel I have a #4 solid wire going out
through the concrete to three 8' ground rods. Total ground rods - 22.
My amp is mounted just above the panel and grounded directly to the panel. I
have a #4 wire going to the ground in the breaker box.
I have my coax, control cables and ground wire continuing to the shack which
is right above the ground panel on the first floor.
All outside ground rod connections are made with Cadwelds.
All coax shields are connected to the bottom of the tower before they go
underground. Also connected the shields where the hardlines terminates on
the tower where I switch to Buryflex for the rotator loops.
Run all coax and control cable inside the Rohn 45 (don't know if that does
any good).
And I even had a witness to the strike. It seems lightning struck a tree
about 300' past my tower very shortly before the tower got hit. My neighbor
looked up to see what got hit. My tower was in line with the tree. He was
standing about 250' from the tower when it got hit. He ran inside after
that. Two close strikes was enough for him.
Maybe someday I will pay a price for not disconnecting anything. But after
doing it this way for 33 years I have suffered virtually no damage.
73,
N2TK, Tony
-----Original Message-----
From: topband-bounces@contesting.com [mailto:topband-bounces@contesting.com]
On Behalf Of Guy Olinger K2AV
Sent: Saturday, July 28, 2012 1:06 AM
To: N2TK, Tony
Cc: topband; donovanf@starpower.net
Subject: Re: Topband: Spark gaps
What is the condition of your 160m radials after the lightning strike? 73,
Guy.
On Fri, Jul 27, 2012 at 7:48 PM, N2TK, Tony <tony.kaz@verizon.net> wrote:
> As a side note, last night when the storm came barreling in with very
> strong winds I was watching the tower as the elements whipped around.
> Bang! First time I saw a direct hit on the tower. Had spots in my eyes
> for a while.
> Tower is about 150' from the kitchen window.
>
> I had everything tuned off but I never disconnect anything.
> Was anxious when I turned on things this morning. Everything is fine
> except the fuse blew on the Prosistel when I turned it on. Replaced
> the fuse and everything is now fine.
> I guess my ground system is working. Couldn't find any burn marks
> anywhere inside or at the tower. With no visual or electrical damage
> maybe the tower has been hit before?
>
> By the way the tower is grounded and I shunt feed it for 160M.
>
> 73,
> N2TK, Tony
>
> -----Original Message-----
> From: topband-bounces@contesting.com [mailto:
> topband-bounces@contesting.com]
> On Behalf Of donovanf@starpower.net
> Sent: Friday, July 27, 2012 10:58 AM
> To: topband
> Subject: Re: Topband: Spark gaps
>
> An air gap using one to two inch diameter balls with only a one or two
> millimeter gap provides a nearly uniform field resulting in the
> fastest breakdown at repeatable and fairly breakdown voltages but
> capable of withstanding kilowatt transmitter power levels.
>
> Ordinary carbon steel balls used in architectural applications should
> provide adequate protection if they are inspected -- and replaced if
> necessary -- after a lightning strike. For example, Wagner Industrial
> sells two inch diameter threaded steel balls for $11.00 each. There
> may be alternative sources.
>
>
> http://www.shopwagnerb2c.com/SPHERES/SPHERES_ST?categoryId=315e03cf-4f
> 11-4ed
> 9-8e89-9fea015509e5&filters=&sortby=1&page=1&pageSize=10&criteria=
>
> Very hard steel balls such as carbon or tungsten are ideal for
> withstanding multiple lightning strikes without need for inspection
> and replacement, but at higher cost.
>
> The balls should be aligned in the horizontal plane, to ensure rain,
> do not bridge the gap. Preferably, the balls should be installed in a
> weather/insect/rhodent proof enclosure.
>
> 73
> Frank
> W3LPL
>
>
> ---- Original message ----
> >Date: Fri, 27 Jul 2012 10:09:16 -0400
> >From: "Tom W8JI" <w8ji@w8ji.com>
> >Subject: Topband: Spark gaps
> >To: "topband" <topband@contesting.com>
> >
> >Has anyone looked at, or looked for, cheap electric fence gaps??
> >
> >My system copper pipes near tower legs work great for me on rigid
> >towers, I can bend them so they spring away from the tower and then
> >slide an inner pipe in or out to set gap distance. I'm thinking of
> >gaps
> for
> wire antennas.
> >
> >Maybe something is good from some other application that is a good
> >bit better than a spark plug.
> >
> >_______________________________________________
> >UR RST IS ... ... ..9 QSB QSB - hw? BK
> _______________________________________________
> UR RST IS ... ... ..9 QSB QSB - hw? BK
>
> _______________________________________________
> UR RST IS ... ... ..9 QSB QSB - hw? BK
>
_______________________________________________
UR RST IS ... ... ..9 QSB QSB - hw? BK
_______________________________________________
UR RST IS ... ... ..9 QSB QSB - hw? BK
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