Shack Grounding

[Tallman]

I know a guy who brought some ground inside. 5 gallon bucket full of dirt with a so239 on the lid.

Those are called "Floating Grounds"??

 

[Slowmover]

Those are called "Floating Grounds"??

Only if he mixed the dirt at 1/3 against 2/3 styrofoam packing beads.

 

[Captain Kilowatt]

A friend of mine worked in the cell phone tower services for one carrier. He had been up the tower most of the day and saw there was a Storm moving into the area. By the time he got down from the tower the storm was very close. Taking shelter inside the equipment feeling safe sat in a chair and took his ease... No sooner than had he relaxed a lightning bolt hit the tower. Not being easily spooked he jumped and hit his head on a shelf. It did not knock him out but he was feeling some pain.
He secured the site and went home and discovered a hole in his right shoe. He decided to go get checked out at the ER and found out how lucky he was. No toes missing, some minor nerve damage but that was it. Well except he needed a shower and a change of skivvies.

Worst place he could have been was inside that building. I was called out during a severe thunderstorm one night to assist the other engineerat one ofour FM sites that wasoff the air. As we approached the site we saw it get hit three times. Deeming it unsafe to approach any closer we went home to await the end of the storm which raged most of the night. We ended up with a blown 4CX250 driver, blown 4CX5000 final, totally wiped three phase rectifier bank, and a fried meter. Not that bad really considering the fireworks. Every breaker in the building was tripped as well.

 

[loosecannon]

thanks BJ thats the info i was looking for.
very cool!
LC

 

[loosecannon]

well i've seen some pretty good suggestions here, but for those that want to do a little better than what others are settling for, here is a diagram of the ultimate grounding setup for your antenna.
WARNING!!!
this is ONLY to be used for CB radio!
any attempt to use this for ham radio will be met with furious ridicule and an instant revocation of your license!

'
LC

 

[BJ radionut]

Looks like a Diagram for under-ground Nuclear Blast

 

[AudioShockwav]

LC
You forgot the rock salt.

73
Jeff

 

[Mustang 131]

There must not have been a common single point ground. If there was current could not flow from one ground point to the other.

Always thought that myself. Separate grounds According to the incident report from the insurance company..and it's your own eyes that can see the damage. After the strike the ground wire insulation melted to ridgid piping ( all new grounding needed) .The j-box coming up from ground blew apart and all the contactors inside the failed. Yes UP FROM EARTH to the MCC. About 30' from the strike, inside the plant.

 

[Flatop]

You might very well change that attitude when Thor throws his mighty hammer Mjolnir at you. All is great until that happens and it only needs to happen once. I know a guy that had an A99 on his house and a single ground rod at the base. $30,000 later after the fire department left and his kitchen cabinets were blown off the walls he decided to do things differently. His radio was in the kitchen and the coax was run behind the cabinets along the wall.

I've got an A99, but I'll take my chances, never had a problem. If lightning strikes it will strike. What damage it will cause, who knows, it's up to the gods. I will cross that bridge if I ever come to it. Maybe your friend should have bolted his kitchen cabinets on properly.

 

[Slowmover]

(Was reading some of Jay in the Mojave old posts on RadioReference early this a.m. and enjoying his antique-y slang of designating high power as The Big Straps).

 

[Captain Kilowatt]

I've got an A99, but I'll take my chances, never had a problem. If lightning strikes it will strike. What damage it will cause, who knows, it's up to the gods. I will cross that bridge if I ever come to it. Maybe your friend should have bolted his kitchen cabinets on properly.

How about YOU define "properly ". That is a rediculous answer actually. Of course they were mounted properly. There is NO electrical code requirement for bolting cabinets to the wall. The freaking LIGHTNING blew the coax cable to hell and back and took out the cabinets in the process.

 

[Tallman]

I've got an A99, but I'll take my chances, never had a problem. If lightning strikes it will strike. What damage it will cause, who knows, it's up to the gods. I will cross that bridge if I ever come to it. Maybe your friend should have bolted his kitchen cabinets on properly.

The problem of leaving it up to the gods is that they have a very perverse sense of humor. As far as crossing that bridge when you come to it, well you might not be here anymore to cross it.
The grounds are for your safety, not just trying to save your gear.

 

[Tokin]

So im rf grounding the shack and lm aware that rf can resonate if the ground lead is of or near certain lengths. Id like to cover 10-11-12 meter range and from using a wavelength calculator I believe im safe with a 50' length. Am I correct?
My other question is what is better to use, 6 awg bare grounding wire or tinned/untinned strap and what width?

 

[Crambone]

So im rf grounding the shack and lm aware that rf can resonate if the ground lead is of or near certain lengths. Id like to cover 10-11-12 meter range and from using a wavelength calculator I believe im safe with a 50' length. Am I correct?
My other question is what is better to use, 6 awg bare grounding wire or tinned/untinned strap and what width?

Well your asking the one question that is sure to stir up arguments and thats anything to do about grounding. Everyone has come to an educated interpretation of the rules. I would suggest going to AARL they have entire sections about grounding. Truth be told when you get into, into it your grounding requirements have a lot to do with you locations soil type and many other factors. Some will megger the grounding system and some will just use a simple ground andthey will be happy.
It is the number one never ending debate questions !

 

[Tokin]

I know it can be a hornets nest of a subject for sure. Im just looking for a non-resonating length to run.
Im in south west florida. Very sandy and my water table is about 3 feet deep. My rod is not more than 6' from my station if I count the 4' from the table top to the floor.
Ive was reading where the army corps of engineers did a study where they found a series of 4 rods connected in series and about 1' deep gave the best results. But im not looking for perfect, just adequate.