[TowerTalk] Grounding

Thu Sep 5 19:33:32 EDT 2019

Chuck...yes, that was the key.  You got it.

   -----------------------------------Wes Attaway (N5WA)(318) 393-3289 - Shreveport, LAComputer/Cellphone ForensicsAttawayForensics.com   ------------------------------------
-------- Original message --------From: Chuck Dietz <w5prchuck at gmail.com> Date: 9/5/19  4:37 PM  (GMT-06:00) To: "Wes Attaway (N5WA)" <wesattaway at bellsouth.net> Cc: john at kk9a.com, Towertalk Reflector <towertalk at contesting.com> Subject: Re: [TowerTalk] Grounding 
Hi Wes, 
That may have happened before I trenched a wire around the shack and connected the station ground to the electrical box ground. No problems since then.
Chuck W5PR
On Thu, Sep 5, 2019 at 3:58 PM Wes Attaway (N5WA) <wesattaway at bellsouth.net> wrote:
Chuck:

I don't want to start a grounding uproar but it sounds like you didn't have

a good single-point ground system, like what Jim Brown describes in his

papers.   You may have good solid grounding but somewhere there is (or was)

apparently a path between your station ground system and another ground

system (your house electrical ground) even though you probably didn't intend

to have two separate ground systems.  That is really the only explanation

for lightning going to ground via a clock and down through your amp to the

amp's ground.

TV and radio station transmitter/antenna sites routinely get hit by

lightning and they rarely go off the air because of a strike.  I worked as a

control room engineer during summers at Channel 12 in Shreveport (a long,

long time ago when we used vacuum tubes) and I don't recall the station ever

going off the air because of a lightning hit.

I no longer have any beams on tall towers but at my previous station I did

have stacked beams on a 70' tower.  I also had a 2M vertical sticking up at

the very top, which I didn't use very often because I never really enjoyed

2M.  I remember walking down my driveway to get the morning paper and

noticing little pieces of fiberglass and metal on the concrete.  It took a

few episodes of this to get me to look up and then I realized that lightning

was hitting my 2M antenna and slowly whittling it down.  It was only 2' or

3' tall when I noticed this.  Nothing ever happened inside my house or

shack, despite all these hits over a period of 20+ years.

For grounding the antenna coax cables I used ICE arrestors bolted to a heavy

copper bar outside my shack window.  The bar was securely fastened to four

8' copper plated ground rods.  Everything in the shack was grounded to one

single piece of copper strap that ran through the wall to the bar outside. I

also tied this ground to the electrical service ground which, luckily,

wasn't too far away.

At my current QTH I have the same old ICE arrestors, still doing fine.  When

we built our current house about 15-years ago I drove two copper-covered

ground rods into the trench where one of the slab beams was about to be

poured, and directly behind the soon-to-be wall of my operating position.

Four ICE arrestors are mounted to 4" copper strap clamped to the tops of the

rods.  My station ground strap (about 4' long) also goes to this spot.

My thought was, rightly or wrongly, that maybe pouring the slab around the

two ground rods would create some form of Ufer ground.  I don't know whether

this is true or not.

The antenna cables are RG-8 BuryFlex run from shack to 4 spots out in the

backyard.  The cable goes through conduit in the slab and then underground

to the 4 ICE arrestor points.  The arrestors are each mounted on a piece of

4" copper strap tightly clamped to the tops of 8' ground rods.  I covered

the ground points with slightly decorative clay pottery pots.  

I also ran another piece of 4" copper strap from the point behind my

operating desk through the side wall of my shack and out to the same point

where the house electrical and telephone service is grounded. This is about

15' of copper strap.  

All I can say is that we get some pretty big thunderstorms at times here in

NW Louisiana with regular hits in various Pine trees in the area and I have

yet to find or experience any damage anywhere.  I do not ever disconnect

anything, or switch anything to ground, at any time.

I had the advantage of being able to do all this as we were building the

house.  Moving into a house and dealing with whatever you have is another

story and I can see that a lot of hams will encounter some frustrating

problems.  Nevertheless, the single-point theory is good advice from Jim.

Unintentionally having separate ground systems is not good and contributes

to a lot of problems.

   -------------------

Wes Attaway (N5WA)

(318) 393-3289 - Shreveport, LA

Computer/Cellphone Forensics

AttawayForensics.com

   -------------------

-----Original Message-----

From: TowerTalk [mailto:towertalk-bounces at contesting.com] On Behalf Of Chuck

Dietz

Sent: Thursday, September 05, 2019 8:37 AM

To: john at kk9a.com

Cc: Towertalk Reflector

Subject: Re: [TowerTalk] Grounding

I had everything disconnected but the ground and a clock on top of an amp.

Lightning surge came through the power lines, through the clock and in to

the amp on its way to ground.

Now I disconnect the ground.

Chuck W5PR

On Thu, Sep 5, 2019 at 8:01 AM <john at kk9a.com> wrote:

> What ground?  Do you use a seperate ground going from your radio

> chassis to a ground rod? I have my equipment bonded together but no RF

> ground and no RFI issues.

>

> John  KK9A/4

>

>

> K9MA wrote:

>

>

> My theory has always been that, with the station equipment well bonded

> together, it is safe to leave the ground connected, as long as

> EVERYTHING else is disconnected. That leaves no path for current to flow

> through anything. I can disconnect the transmitting antennas with one

> coax, all the control cables and rx antennas with another big connector,

> and power with one 120 and one 240 V plug. That just leaves the ethernet

> cable, which I try not to forget.

>

> In any case, my primary goal is to prevent a fire, and disconnecting the

> ground from the equipment probably wouldn't help there. I hope I never

> have to test that theory.

>

> 73,

>

> Scott K9MA

>

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